CN119200735B - A LDO circuit and method for improving output overcharge - Google Patents
A LDO circuit and method for improving output overcharge Download PDFInfo
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- CN119200735B CN119200735B CN202411696922.0A CN202411696922A CN119200735B CN 119200735 B CN119200735 B CN 119200735B CN 202411696922 A CN202411696922 A CN 202411696922A CN 119200735 B CN119200735 B CN 119200735B
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Abstract
本发明公开了一种改善输出过充的LDO电路和方法，包括比较器，第一放大器通过第一NMOS管连接低静态功耗电路，第一分压采样电阻和第二分压采样电阻连接所述低静态功耗电路并生成反馈电压，比较器通过第四PMOS管与低静态功耗电路连接，并基于一个电路内部产生的第二基准电压和驱动电压进行比较，控制所述第四PMOS管开关控制器的开启和关断；第一放大器基于第一基准电压和反馈电压，输出第一电压信号，并通过第一NMOS管和低静态功耗电路输出驱动电压，第二PMOS管基于外部输入电压和驱动电压产生并控制输出电压；通过比较器电路调制驱动电压来控制功率管，以改善在空载下慢速启动时的输出电压过充和改善空载热插拔时输出电压过充。
The present invention discloses an LDO circuit and method for improving output overcharging, comprising a comparator, a first amplifier connected to a low static power consumption circuit through a first NMOS tube, a first voltage-dividing sampling resistor and a second voltage-dividing sampling resistor connected to the low static power consumption circuit and generating a feedback voltage, a comparator connected to the low static power consumption circuit through a fourth PMOS tube, and based on a comparison between a second reference voltage generated inside a circuit and a driving voltage, controlling the on and off of a switch controller of the fourth PMOS tube; the first amplifier outputs a first voltage signal based on the first reference voltage and the feedback voltage, and outputs a driving voltage through the first NMOS tube and the low static power consumption circuit, and the second PMOS tube generates and controls the output voltage based on an external input voltage and the driving voltage; the driving voltage is modulated by the comparator circuit to control the power tube, so as to improve the output voltage overcharging during slow startup under no-load and improve the output voltage overcharging during no-load hot plugging.
Description
Technical Field
The invention relates to the technical field of power management chips, in particular to an LDO circuit and a method for improving output overcharge.
Background
Referring to fig. 2, fig. 2 shows an LDO circuit with static power consumption in the prior art. As shown in fig. 2, the modified circuit may include a circuit input terminal, a circuit output terminal and a ground terminal, a first amplifier, a second amplifier, a third amplifier, a PMOS transistor M3, and an output sampling module.
When the voltage of an external input end is lower than the preset voltage of an output end, the voltage of the output end of the circuit is reduced along with the reduction of the voltage of the input end of the circuit, at the moment, a first sampling signal is reduced, the grid voltage of M1 is increased, the grid voltage of M3 is reduced, the PMOS tube M3 is in a linear region, a third amplifier outputs the grid voltage of M4 based on the drain voltage of M2 and the voltage of the output end, the source voltage of M4 is changed along with the voltage of the output end and has the same value, at the moment, the PMOS tube M2 is in the linear region, the grid, drain and source voltages of the PMOS tube M2 and the grid, drain and source voltages of the PMOS tube M3 are respectively equal, the current IM2 of the PMOS tube M2 and the current IM3 of the PMOS tube M3 are in a mirror image relationship, and the mirror image relationship is that:
The preset voltage at the output end is greater than or equal to the first reference signal, the IM2 is the current of the PMOS tube M2, the IM3 is the current of the PMOS tube M3, (W/L) M2 is the width-to-length ratio of the PMOS tube M2, and (W/L) M3 is the width-to-length ratio of the PMOS tube M3, so that when the voltage at the input end is lower than the preset voltage at the output end, the current of the PMOS tube M2 is:
Thereby avoiding an increase in static power consumption of the circuit caused by current mirror mismatch.
It is clear to those skilled in the art that the method has very high application value in the field of low power consumption and lithium batteries, and is characterized in that under the condition of low VIN, M2 is limited by M4, and the condition of circuit static power consumption increase caused by current mirror mismatch does not occur. In order to improve response data and load capacity, the second stage amplifier of the low-power LDO on the market conventionally uses a P-tube current mirror to copy the current of a power tube, but the prior art has the following drawbacks:
Under no-load conditions, when VIN is low, the overall current is small, that is, the response speed of the op-amp is slow, and the problem of VOUT overcharge can occur, which includes:
When VIN is started at a slow speed, VOUT may be overcharged;
under the condition of VIN residual electric heating plug, VOUT can be overcharged.
Disclosure of Invention
In view of the above-mentioned shortcomings in the current power management chip technology field, the present invention provides an LDO circuit and method for improving output overcharge, which can prevent the problem of output voltage overcharge when the low-speed start and residual electric heat plug are powered on under no load.
In order to achieve the above purpose, the embodiment of the present invention adopts the following technical scheme:
An LDO circuit for improving output overcharge comprises a first amplifier, a first NMOS tube, a second PMOS tube, a low static power consumption circuit, a fourth PMOS tube, a first voltage division sampling resistor, a second voltage division sampling resistor, and an external input voltage First reference voltageAnd output voltageThe power supply circuit is characterized by further comprising a comparator, wherein the comparator is connected with the low-static power consumption circuit through a fourth PMOS tube and controls the on and off of a fourth PMOS tube switch controller based on comparison of a second reference voltage and a driving voltage generated inside the circuit, the first amplifier outputs a first voltage signal based on the first reference voltage and the feedback voltage and outputs a driving voltage through the first NMOS tube and the low-static power consumption circuit, the second PMOS tube generates and controls an output voltage based on an external input voltage and the driving voltage, and the driving voltage is modulated by the comparator circuit to control the power tube.
According to one aspect of the invention, the first NMOS tube is a common source amplifier, the source electrode is grounded, the drain electrode is connected with the drain electrode of the fourth PMOS tube and the low static power consumption circuit, the grid electrode is connected with the output end of the first amplifier and outputs grid electrode driving voltage based on a first voltage signal and bias current provided by low static power consumption, the source electrode of the second PMOS tube is connected with external input voltage, the grid electrode is connected with the low static power consumption circuit, and the drain electrode is connected with a first voltage division sampling resistor.
According to one aspect of the invention, the low static power consumption circuit comprises a first PMOS tube, a third PMOS tube and a second amplifier, wherein the source electrode of the first PMOS tube is connected with the source electrode of the second PMOS tube, the grid electrode of the first PMOS tube is connected with the grid electrode of the second PMOS tube, the drain electrode of the third PMOS tube is connected with the source electrode of the third PMOS tube, the source electrode of the third PMOS tube is connected with the drain electrode of the first PMOS tube and the input end of the second amplifier, the grid electrode of the third PMOS tube is connected with the output end of the second amplifier, and the drain electrode of the third PMOS tube is connected with the drain electrode of the fourth PMOS tube and the drain electrode of the first NMOS tube.
According to one aspect of the invention, the second amplifier and the third PMOS transistor form a buffer, and the drain electrode of the first PMOS transistor is controlled to follow the output voltage based on the output voltage, so as to avoid the increase of static power consumption of the circuit caused by mismatch of current mirror images.
According to one aspect of the invention, the source electrode of the fourth PMOS transistor is connected to the source electrode of the third PMOS transistor, the drain electrode is connected to the driving voltage, the gate electrode is connected to the output end of the comparator, and the fourth PMOS transistor pulls up the driving voltage rapidly when being turned on.
According to one aspect of the invention, a negative feedback loop is formed by a loop formed by a bias current provided by the first amplifier, the first NMOS tube, the low static power consumption circuit, the second PMOS tube, the first sampling voltage dividing resistor and the second sampling voltage dividing resistor, one end of the first voltage dividing resistor is connected to the low static power consumption circuit and the drain electrode of the second PMOS tube, the other end of the first voltage dividing resistor is connected with one end of the second voltage dividing resistor and is connected with a feedback voltage signal, the other end of the second voltage dividing resistor is grounded, the negative feedback loop enables the first reference voltage and the feedback voltage to be consistent, and an output voltage is set through the first sampling voltage dividing resistor and the second sampling voltage dividing resistor, and the output voltage is as follows:
。
The method for improving the low-speed starting output overcharging under no-load comprises the following steps that a comparator is connected with a low-static power consumption circuit through a fourth PMOS tube and is used for comparing based on a second reference voltage and a driving voltage to control the on and off of a switch controller of the fourth PMOS tube, a first amplifier is used for outputting a first voltage signal based on the first reference voltage and the feedback voltage and outputting a driving voltage through a first NMOS tube and the low-static power consumption circuit, and the second PMOS tube is used for generating and controlling the output voltage based on the external input voltage and the driving voltage.
According to one aspect of the invention, in idle slow start, when the external input voltage exceeds the minimum working voltage, the negative feedback loop pulls down the driving voltage to the full-on state of the power tube, the driving voltage is lower than the second reference voltage, the comparator outputs a high level, the switch fourth PMOS tube is in a cut-off state, when the external input voltage is about to be higher than the output voltage set by the first sampling voltage dividing resistor and the second sampling voltage dividing resistor, the negative feedback loop starts to pull up the driving voltage, the comparator outputs a low level after detecting that the driving voltage is higher than the second reference voltage, and the switch fourth PMOS tube is started, so that the power tube is quickly regulated.
The method for improving residual electric heating plug output overcharge under no-load comprises the following steps that a comparator is connected with a low-static power consumption circuit through a fourth PMOS tube and is used for comparing based on a second reference voltage and a driving voltage to control the on and off of a switch controller of the fourth PMOS tube, a first amplifier is used for outputting a first voltage signal based on the first reference voltage and a feedback voltage and outputting a driving voltage through a first NMOS tube and the low-static power consumption circuit, and the second PMOS tube is used for generating and controlling an output voltage based on an external input voltage and the driving voltage.
According to one aspect of the invention, under the condition of pulling out the external input voltage in an idle hot plug mode, when the external input voltage is lower than the output voltage set through the first sampling voltage dividing resistor and the second sampling voltage dividing resistor, the negative feedback loop pulls down the driving voltage to the full-on state of the power tube, the driving voltage is lower than the second reference voltage, the comparator outputs a high level, the switch fourth PMOS tube is in a cut-off state, when the external input voltage is powered on in a hot plug mode, the feedback loop starts to pull up the driving voltage and enables the driving voltage to be higher than the second reference voltage, the comparator detects the rear output low level and turns on the switch fourth PMOS tube, so that the power tube is quickly regulated, and the overcharging of the output voltage is improved.
The low-static-power-consumption power supply circuit has the advantages that the first amplifier is connected with a low-static-power-consumption circuit through a first NMOS tube, a first voltage division sampling resistor and a second voltage division sampling resistor are connected with the low-static-power-consumption circuit and generate feedback voltage, the comparator is connected with the low-static-power-consumption circuit through a fourth PMOS tube and compares the second reference voltage and the driving voltage generated inside the circuit to control the on and off of a switch controller of the fourth PMOS tube, the first amplifier outputs a first voltage signal based on the first reference voltage and the feedback voltage and outputs driving voltage through the first NMOS tube and the low-static-power-consumption circuit, the second PMOS tube generates and controls output voltage based on external input voltage and the driving voltage, and the power tube is controlled by modulating the driving voltage through the comparator circuit so as to improve the over-charging of the output voltage during slow starting under no-load and the over-load hot plug.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a circuit diagram of an LDO circuit for improving output overcharging according to the present invention;
FIG. 2 is a circuit diagram of a prior art LDO circuit for improving output overcharging according to the present invention;
FIG. 3 is a diagram illustrating an effect of no-load hot plug simulation of an LDO circuit for improving output overcharging according to the present invention;
FIG. 4 is a diagram showing a slow start simulation effect of an idle external input voltage of an LDO circuit for improving output overcharge according to the present invention;
FIG. 5 is a graph showing the effect of improving the variation of the quiescent current of an output overcharged LDO circuit according to the present invention with the external input voltage;
FIG. 6 is a diagram showing the effect of no-load hot plug simulation of a non-comparator circuit for improving output overcharging LDO circuit according to the present invention;
FIG. 7 is a diagram showing the effect of slow start simulation of an unloaded external input voltage without a comparator for an LDO circuit with improved output overcharging according to the present invention;
FIG. 8 is a diagram of an embodiment of an LDO circuit for improving output overcharging according to the present invention;
fig. 9 is a fifth diagram of an embodiment of an LDO circuit for improving output overcharge according to the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Embodiment one:
as shown in FIG. 1, the LDO circuit for improving output overcharge comprises a first amplifier, a first NMOS tube A second PMOS tubeLow static power consumption circuit, fourth PMOS tube switchFirst voltage dividing sampling resistorSecond voltage division sampling resistorAnd a comparator, and an external input voltagePower supply, ground voltage GND, first reference voltageAnd output voltage. The first amplifier is connected with the low-static power consumption circuit through a first NMOS tube, and the first voltage division sampling resistor and the second voltage division sampling resistor are connected with the low-static power consumption circuit and generate feedback voltage. The first amplifier is based on a first reference voltageAnd feedback voltageOutput voltage control signal。Is a common source amplifier with the source electrode grounded and the drain electrode connectedAnd the low static power consumption circuit, the grid is connected with the output end of the first amplifier and is based onAnd low static power consumption, and outputting the gate driving voltage。The grid electrode of the (E) is connected with the output end of the comparator, and the drain electrode is connected withAnd the source electrode is connected to the low static power consumption circuit.The source electrode of the transistor is connected with an external input voltage, the gate is connected to the low static power consumption circuit, drain access to the,Based on external input voltageAnd drive voltageControlling output voltageIs of a size of (a) and (b).Is connected with one end of the low static power consumption circuitIs provided with a drain electrode of (c),Is connected with the other end ofOne end of (1) is connected with a feedback voltage signal;The other end of which is grounded. A first amplifier,Bias current provided by low static power consumption circuit,、AndThe loop is formed into a negative feedback loop, and the negative feedback loop makes the reference voltageAnd feedback voltageUniform and pass throughAndSetting the output voltageThe output voltage is: . The output voltage set by the voltage dividing resistor is a preset output voltage. The comparator is based on a second reference voltage generated internally in a circuit And drive voltageComparing to control the switchIs provided for the opening and closing of (a).
The low static power consumption circuit comprises、And a second amplifier, which is coupled to the first amplifier,Source access to (a)And is connected with an external input voltage, gate accessGate, drain access to、A source of (a); Source access to (a) And the drain of the second amplifier and the input terminal of the second amplifier and controlThe grid electrode is connected with the output end of the second amplifier, and the drain electrode is connected withDrain and of (2)Is formed on the drain electrode of the transistor. Wherein the second amplifier andForms a buffer based on the output voltageAnd controlIs connected to the drain follower output voltage of (a)And the static power consumption of the circuit is prevented from being increased due to the mismatching of the current mirror images.
At idle loadIn the case of a slow-start-up,Rise slowly whenAfter exceeding the minimum operating voltage, the negative feedback loop willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upAscending whenWhen the voltage is about to be higher than the preset output voltage, the negative feedback loop starts to pull up slowlyVoltage whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved.
Under the condition of no-load hot plug external input voltage pulling-out, when the external input voltage is removedAfter that, whenBelow a preset levelAfter that, the negative feedback loop is pulled downSo that the power tube is fully opened andFollowing upThe drop-off is carried out, at this time,Voltage is lower thanComparator outputs high level, switchIn the cut-off state whenWhen hot plug is powered on, the negative feedback loop starts to pull upVoltage whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, and the output voltage overcharge is improved. Then whenAbove the preset valueAt the time, since the power tube is regulatedThe overcharge condition of (2) is greatly improved. The no-load condition includes a condition in which no load is connected, and a condition in which the load is hung on the output voltage but the switch turns the load off.
As shown in figure 3 of the drawings,Under the condition of inconsistent residual electric heating plug-in speed,Is a variation of (c). When removingAfter that, the input capacitor is used for supplying power, and the static power consumption of the LDO under no load is small and unchanged, soThe hot plug is charged when the power is dropped at a constant speedWhen the residual power of the power supply is higher than 3.24V, the negative feedback operational amplifier is in a normal regulation state, soUnchanged, whenAt a voltage lower than 3.24V,Start to appear followingChange of drop, simulation effect graphAt the time of powering up at 3uS speed, atWhen falling within the range of 2.99-3.24V,Overcharging occurs andThe closer to the presetThe greater the overcharge, as seen in the above figures,Maximum overcharge was 3.4V (normalWhen the value of the voltage is =4.3v,=3.25V)。
As shown in figure 4 of the drawings,At a rate of 10mS, from 0V to 4.3V,The overcharge is small, the maximum amplitude of the overcharge is 3.256V, and the overcharge is recovered to the preset state after the duration time of the overcharge is about 27mS。
As shown in FIG. 5, the abscissa isThe ordinate is the quiescent current of the entire LDO circuit whenWhen=3.25v, IQ is maximum, and is 1.54uA (normalWhen the value of the voltage is =4.3v, iq=748nA).
As shown in figure 6 of the drawings,The residual heat plugging condition of (2) is the same as that of FIG. 3, but the response speed of the circuit is slow because of not adding a comparison circuit, whenAfter overcharge, the power tube is in an off state untilFalls to a presetAfter that, the negative feedback releases the power tube, so in the simulation graph,After overcharging, it lasts 3-4 seconds.
As shown in figure 7 of the drawings,At a rate of 10mS, from 0V to 4.3V,The maximum amplitude of the overcharge is 3.33V, and the overcharge duration is about 421mS before the overcharge is restored to the preset state。
By changing the partial structure in the present embodiment, the same functions and effects can be obtained in the new embodiment.
The low-static-power-consumption power supply circuit has the advantages that the first amplifier is connected with a low-static-power-consumption circuit through a first NMOS tube, a first voltage division sampling resistor and a second voltage division sampling resistor are connected with the low-static-power-consumption circuit and generate feedback voltage, the comparator is connected with the low-static-power-consumption circuit through a fourth PMOS tube and compares the second reference voltage and the driving voltage generated inside the circuit to control the on and off of a switch controller of the fourth PMOS tube, the first amplifier outputs a first voltage signal based on the first reference voltage and the feedback voltage and outputs driving voltage through the first NMOS tube and the low-static-power-consumption circuit, the second PMOS tube generates and controls output voltage based on external input voltage and the driving voltage, and the power tube is controlled by modulating the driving voltage through the comparator circuit so as to improve the over-charging of the output voltage during slow starting under no-load and the over-load hot plug.
Embodiment two:
as shown in fig. 1, a method for improving output overcharge at low speed under no-load is provided, and the embodiment is based on the LDO circuit of the first embodiment, and the specific method steps of the embodiment are as follows:
S1, in idle load In the case of a slow-start-up,Rise slowly whenAfter exceeding the minimum operating voltage, the negative feedback loop willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upRising.
S2, whenThe voltage is about to be higher than the preset valueAt voltage, the negative feedback loop starts to pull up slowlyA voltage.
S3, whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved.
The partial structure of the LDO circuit in the embodiment can be replaced and changed to obtain a new embodiment of the LDO circuit structure, and the new embodiment has the same functions and effects.
The comparator circuit is modified as in the fourth embodiment. The comparator includes:、、、 Current source 、And。Is grounded at the source and connected to the drainA source of (a); Is connected with the grid electrode and the drain electrode of (C) A gate electrode of (a); Is connected with the source electrode of (C) Drain electrode is connected toA gate electrode of (a); Drain junction of (2) And is connected withGate-to-source connection. Wherein the method comprises the steps of,Based on current sourcesGenerating a reference voltageFor makingGate voltage of (a); based on current sources 、AndVoltage generation ofIs the drain voltage of (2);Generating an output voltage,As a means ofIs provided for the switching control signal of (a). When (when)Will be overcharged and negative feedback will be raisedWhen (1) is in the process ofDetection ofVoltage is higher thanAfter that, the processing unit is configured to,The switch-off is performed and the switch-off is performed,The voltage is at high levelCut off, therebyVoltage becomes low level, switchOpening the valveIs short circuited. At idle loadIn the case of a slow-start-up,Rise slowly whenAfter exceeding the minimum working voltage, the negative feedback operational amplifier willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upAscending whenThe voltage is about to be higher than the preset valueAt voltage, the negative feedback loop starts to pull up slowlyVoltage of the presetFor the output voltage set by the voltage dividing resistorThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved. Under the condition of no-load hot plug, when the saidAfter that, whenBelow a preset levelAfter that, the negative feedback is pulled downSo that the power tube is fully opened andFollowing upThe drop-off is carried out, at this time,Voltage is lower thanComparator outputs high level, switchIn the cut-off state whenWhen hot plug is powered on, the negative feedback loop starts to pull upVoltage whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved. The no-load hot plug condition comprises the condition that no load is connected, and the condition that the load is hung on the output voltage but the switch turns off the load.
The comparator circuit is modified as in embodiment five. The comparator includes:、、、 And a current source . The saidIs grounded at the source and connected at the gateIs connected with the grid electrode and the drain electrode ofA gate drain is connected at the same time; Is grounded at the source and grounded at the drain A drain electrode of (2); Is connected with a second reference voltage Source electrode connected with current source;Is connected with the driving voltage by the grid electrodeSource electrode connected with current sourceDrain electrode is connected toThe drain electrode of the transistor is connected with a first voltage signal in parallel, a current sourceAccessing external input voltage. Wherein the method comprises the steps of、、、And a current sourceConstitute a five-tube amplifier based on the second reference voltageAnd drive voltageComparing and outputting voltage. At idle loadIn the case of a slow-start-up,Rise slowly whenAfter exceeding the minimum working voltage, the negative feedback operational amplifier willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upAscending whenThe voltage is about to be higher than the preset valueAt voltage, the negative feedback loop starts to pull up slowlyVoltage of the presetFor the output voltage set by the voltage dividing resistorThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved. Under the condition of no-load hot plug, when the saidAfter that, whenBelow a preset levelAfter that, the negative feedback is pulled downSo that the power tube is fully opened andFollowing upThe drop-off is carried out, at this time,Voltage is lower thanComparator outputs high level, switchIn the cut-off state whenWhen hot plug is powered on, the negative feedback loop starts to pull upVoltage whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, and the output voltage overcharge is improved. Then whenAbove the preset valueAt the time, since the power tube is regulatedThe overcharge condition is greatly improved. The no-load condition includes a condition in which no load is connected, and a condition in which the load is hung on the output voltage but the switch turns the load off.
As shown in figure 3 of the drawings,Under the condition of inconsistent residual electric heating plug-in speed,Is a variation of (c). When removingAfter that, the input capacitor is used for supplying power, and the static power consumption of the LDO under no load is small and unchanged, soThe hot plug is charged when the power is dropped at a constant speedWhen the residual power of the power supply is higher than 3.24V, the negative feedback operational amplifier is in a normal regulation state, soUnchanged, whenAt a voltage lower than 3.24V,Start to appear followingChange of drop, simulation effect graphAt the time of powering up at 3uS speed, atWhen falling within the range of 2.99-3.24V,Overcharging occurs andThe closer to the presetThe greater the overcharge, as seen in the above figures,Maximum overcharge was 3.4V (normalWhen the value of the voltage is =4.3v,=3.25V)。
As shown in figure 4 of the drawings,At a rate of 10mS, from 0V to 4.3V,The overcharge is small, the maximum amplitude of the overcharge is 3.256V, and the overcharge is recovered to the preset state after the duration time of the overcharge is about 27mS。
As shown in figure 6 of the drawings,The residual heat plugging condition of (2) is the same as that of FIG. 3, but the response speed of the circuit is slow because of not adding a comparison circuit, whenAfter overcharge, the power tube is in an off state untilFalls to a presetAfter that, the negative feedback releases the power tube, so in the simulation graph,After overcharging, it lasts 3-4 seconds.
As shown in figure 7 of the drawings,At a rate of 10mS, from 0V to 4.3V,The maximum amplitude of the overcharge is 3.33V, and the overcharge duration is about 421mS before the overcharge is restored to the preset state。
By changing the partial structure in the present embodiment, the same functions and effects can be obtained in the new embodiment.
The low-static-power-consumption power supply circuit has the advantages that the first amplifier is connected with a low-static-power-consumption circuit through a first NMOS tube, a first voltage division sampling resistor and a second voltage division sampling resistor are connected with the low-static-power-consumption circuit and generate feedback voltage, the comparator is connected with the low-static-power-consumption circuit through a fourth PMOS tube and compares the second reference voltage and the driving voltage generated inside the circuit to control the on and off of a switch controller of the fourth PMOS tube, the first amplifier outputs a first voltage signal based on the first reference voltage and the feedback voltage and outputs driving voltage through the first NMOS tube and the low-static-power-consumption circuit, the second PMOS tube generates and controls output voltage based on external input voltage and the driving voltage, and the power tube is controlled by modulating the driving voltage through the comparator circuit so as to improve the over-charging of the output voltage during slow starting under no-load and the over-load hot plug.
Embodiment III:
As shown in FIG. 1, the method for improving the residual electric hot plug output overcharge under no load is based on the LDO circuit of the first embodiment, and the specific method of the embodiment comprises the following steps of S1 Under the condition of pulling out the seed,Rise slowly whenAfter exceeding the minimum working voltage, the negative feedback operational amplifier willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upRising.
S2, whenThe voltage is about to be higher than the preset valueAt voltage, the negative feedback loop starts to pull up slowlyA voltage.
S3, whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, and the output voltage overcharge is improved. Then whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved.
The partial structure of the LDO circuit in the embodiment can be replaced and changed to obtain a new embodiment of the LDO circuit structure, and the new embodiment has the same functions and effects.
The comparator circuit is modified as in the fourth embodiment. The comparator includes:、、、 Current source 、And。Is grounded at the source and connected to the drainA source of (a); Is connected with the grid electrode and the drain electrode of (C) A gate electrode of (a); Is connected with the source electrode of (C) Drain electrode is connected toA gate electrode of (a); Drain junction of (2) And is connected withGate-to-source connection. Wherein the method comprises the steps of,Based on current sourcesGenerating a reference voltageFor makingGate voltage of (a); based on current sources 、、AndVoltage generation ofIs the drain voltage of (2);Generating an output voltage,As a means ofIs provided for the switching control signal of (a). When (when)Will be overcharged and negative feedback will be raisedWhen (1) is in the process ofDetection ofVoltage is higher thanAfter that, the processing unit is configured to,The switch-off is performed and the switch-off is performed,The voltage is at high levelCut off, therebyVoltage becomes low level, switchOpening the valveIs short circuited. At idle loadIn the case of a slow-start-up,Rise slowly whenAfter exceeding the minimum working voltage, the negative feedback operational amplifier willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upAscending whenThe voltage is about to be higher than the preset valueAt voltage, the negative feedback loop starts to pull up slowlyVoltage of the presetFor the output voltage set by the voltage dividing resistorThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved. Under the condition of no-load hot plug, when the saidAfter that, whenBelow a preset levelAfter that, the negative feedback is pulled downSo that the power tube is fully opened andFollowing upThe drop-off is carried out, at this time,Voltage is lower thanComparator outputs high level, switchAt cut-offState whenWhen hot plug is powered on, the negative feedback loop starts to pull upVoltage whenThe voltage rises but not yet to limit the power tube regulationIn the course of (1) the comparator detects a voltage higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueAt the time, since the power tube is regulatedThe overcharge condition is greatly improved. The no-load hot plug condition comprises the condition that no load is connected, and the condition that the load is hung on the output voltage but the switch turns off the load.
The comparator circuit is modified as in embodiment five. The comparator includes:、、、 And a current source . The saidIs grounded at the source and connected at the gateIs connected with the grid electrode and the drain electrode ofA gate drain is connected at the same time; Is grounded at the source and grounded at the drain A drain electrode of (2); Is connected with a second reference voltage Source electrode connected with current source;Is connected with the driving voltage by the grid electrodeSource electrode connected with current sourceDrain electrode is connected toThe drain electrode of the transistor is connected with a first voltage signal in parallel, a current sourceAccessing external input voltage. Wherein the method comprises the steps of、、、And a current sourceConstitute a five-tube amplifier based on the second reference voltageAnd drive voltageComparing and outputting voltage. At idle loadIn the case of a slow-start-up,Rise slowly whenAfter exceeding the minimum working voltage, the negative feedback operational amplifier willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upAscending whenThe voltage is about to be higher than the preset valueAt voltage, the negative feedback loop starts to pull up slowlyVoltage of the presetFor the output voltage set by the voltage dividing resistorThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved. Under the condition of no-load hot plug, when the saidAfter that, whenBelow a preset levelAfter that, the negative feedback is pulled downSo that the power tube is fully opened andFollowing upThe drop-off is carried out, at this time,Voltage is lower thanComparator outputs high level, switchIn the cut-off state whenWhen hot plug is powered on, the negative feedback loop starts to pull upVoltage whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, and the output voltage overcharge is improved. Then whenAbove the preset valueAt the time, since the power tube is regulatedThe overcharge condition is greatly improved. The no-load condition includes a condition in which no load is connected, and a condition in which the load is hung on the output voltage but the switch turns the load off.
As shown in figure 3 of the drawings,Under the condition of inconsistent residual electric heating plug-in speed,Is a variation of (c). When removingAfter that, the input capacitor is used for supplying power, and the static power consumption of the LDO under no load is small and unchanged, soThe hot plug is charged when the power is dropped at a constant speedWhen the residual power of the power supply is higher than 3.24V, the negative feedback operational amplifier is in a normal regulation state, soUnchanged, whenAt a voltage lower than 3.24V,Start to appear followingChange of drop, simulation effect graphAt the time of powering up at 3uS speed, atWhen falling within the range of 2.99-3.24V,Overcharging occurs andThe closer to the presetThe greater the overcharge, as seen in the above figures,Maximum overcharge was 3.4V (normalWhen the value of the voltage is =4.3v,=3.25V)。
As shown in figure 4 of the drawings,At a rate of 10mS, from 0V to 4.3V,The overcharge is small, the maximum amplitude of the overcharge is 3.256V, and the overcharge is recovered to the preset state after the duration time of the overcharge is about 27mS。
As shown in figure 6 of the drawings,The residual heat plugging condition of (2) is the same as that of FIG. 3, but the response speed of the circuit is slow because of not adding a comparison circuit, whenAfter overcharge, the power tube is in an off state untilFalls to a presetAfter that, the negative feedback releases the power tube, so in the simulation graph,After overcharging, it lasts 3-4 seconds.
As shown in figure 7 of the drawings,At a rate of 10mS, from 0V to 4.3V,The maximum amplitude of the overcharge is 3.33V, and the overcharge duration is about 421mS before the overcharge is restored to the preset state。
By changing the partial structure in the present embodiment, the same functions and effects can be obtained in the new embodiment.
The low-static-power-consumption power supply circuit has the advantages that the first amplifier is connected with a low-static-power-consumption circuit through a first NMOS tube, a first voltage division sampling resistor and a second voltage division sampling resistor are connected with the low-static-power-consumption circuit and generate feedback voltage, the comparator is connected with the low-static-power-consumption circuit through a fourth PMOS tube and compares the second reference voltage and the driving voltage generated inside the circuit to control the on and off of a switch controller of the fourth PMOS tube, the first amplifier outputs a first voltage signal based on the first reference voltage and the feedback voltage and outputs driving voltage through the first NMOS tube and the low-static-power-consumption circuit, the second PMOS tube generates and controls output voltage based on external input voltage and the driving voltage, and the power tube is controlled by modulating the driving voltage through the comparator circuit so as to improve the over-charging of the output voltage during slow starting under no-load and the over-load hot plug.
Embodiment four:
As shown in FIG. 8, an LDO circuit for improving output overcharging comprises a first amplifier, 、Circuit and switch with low static power consumption、、And comparator, and external power supplyPower supply, ground voltage GND, reference voltageAnd an external output voltage. The first amplifier is connected with the low-static power consumption circuit through a first NMOS tube, and the first voltage division sampling resistor and the second voltage division sampling resistor are connected with the low-static power consumption circuit and generate feedback voltage. The first amplifier is based on a first reference voltageAnd feedback voltageOutput voltage control signal。Is a common source amplifier with the source electrode grounded and the drain electrode connectedAnd the low static power consumption circuit, the grid is connected with the output end of the first amplifier and is based onAnd low static power consumption, and outputting the gate driving voltage。The grid electrode of the (E) is connected with the output end of the comparator, and the drain electrode is connected withAnd the source electrode is connected to the low static power consumption circuit.The source electrode of the transistor is connected with an external input voltage, the gate is connected to the low static power consumption circuit, drain access to the,Based on external input voltageAnd drive voltageControlling output voltageIs of a size of (a) and (b).Is connected with one end of the low static power consumption circuitIs provided with a drain electrode of (c),Is connected with the other end ofOne end of (1) is connected with a feedback voltage signal;The other end of which is grounded. A first amplifier,Bias current provided by low static power consumption circuit,、AndThe loop is formed into a negative feedback loop, and the negative feedback loop makes the reference voltageAnd feedback voltageUniform and pass throughAndSetting the output voltageThe output voltage is: . The comparator controls the switch Is provided for the opening and closing of (a). The low static power consumption circuit comprises、And a second amplifier, which is coupled to the first amplifier,Source access to (a)And is connected with an external input voltage, gate accessGate, drain access to、A source of (a); Source access to (a) And the drain of the second amplifier and the input terminal of the second amplifier and controlThe grid electrode is connected with the output end of the second amplifier, and the drain electrode is connected withDrain and of (2)Is formed on the drain electrode of the transistor. Wherein the second amplifier andForms a buffer based on the output voltageAnd controlIs connected to the drain follower output voltage of (a)And the static power consumption of the circuit is prevented from being increased due to the mismatching of the current mirror images.
In this embodiment, the comparator includes:、、、 Current source 、And。Is grounded at the source and connected to the drainA source of (a); Is connected with the grid electrode and the drain electrode of (C) A gate electrode of (a); Is connected with the source electrode of (C) Drain electrode is connected toA gate electrode of (a); Drain junction of (2) And is connected withGate-to-source connection. Wherein the method comprises the steps of,Based on current sourcesGenerating a reference voltageFor makingGate voltage of (a); based on current sources 、AndVoltage generation ofIs the drain voltage of (2);Generating an output voltage,As a means ofIs provided for the switching control signal of (a). When (when)Will be overcharged and negative feedback will be raisedWhen (1) is in the process ofDetection ofVoltage is higher thanAfter that, the processing unit is configured to,The switch-off is performed and the switch-off is performed,The voltage is at high levelCut off, therebyVoltage becomes low level, switchOpening the valveIs short circuited. At idle loadIn the case of a slow-start-up,Rise slowly whenAfter exceeding the minimum working voltage, the negative feedback operational amplifier willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upAscending whenThe voltage is about to be higher than the preset valueAt voltage, the negative feedback loop starts to pull up slowlyVoltage of the presetFor the output voltage set by the voltage dividing resistorThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueAt the time, since the power tube is regulatedThe overcharge condition is greatly improved.
Under the condition of no-load hot plug, when the saidAfter that, whenBelow a preset levelAfter that, the negative feedback is pulled downSo that the power tube is fully opened andFollowing upThe drop-off is carried out, at this time,Voltage is lower thanComparator outputs high level, switchIn the cut-off state whenWhen hot plug is powered on, the negative feedback loop starts to pull upVoltage whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueAt the time, since the power tube is regulatedThe overcharge condition is greatly improved. The no-load hot plug condition comprises the condition that no load is connected, and the condition that the load is hung on the output voltage but the switch turns off the load.
As shown in figure 3 of the drawings,Under the condition of inconsistent residual electric heating plug-in speed,Is a variation of (c). When removingAfter that, the input capacitor is used for supplying power, and the static power consumption of the LDO under no load is small and unchanged, soThe hot plug is charged when the power is dropped at a constant speedWhen the residual power of the power supply is higher than 3.24V, the negative feedback operational amplifier is in a normal regulation state, soUnchanged, whenAt a voltage lower than 3.24V,Start to appear followingChange of drop, simulation effect graphAt the time of powering up at 3uS speed, atWhen falling within the range of 2.99-3.24V,Overcharging occurs andThe closer to the presetThe greater the overcharge, as seen in the above figures,Maximum overcharge was 3.4V (normalWhen the value of the voltage is =4.3v,=3.25V)。
As shown in figure 4 of the drawings,At a rate of 10mS, from 0V to 4.3V,The overcharge is small, the maximum amplitude of the overcharge is 3.256V, and the overcharge is recovered to the preset state after the duration time of the overcharge is about 27mS。
As shown in figure 6 of the drawings,The residual heat plugging condition of (2) is the same as that of FIG. 3, but the response speed of the circuit is slow because of not adding a comparison circuit, whenAfter overcharge, the power tube is in an off state untilFalls to a presetAfter that, the negative feedback releases the power tube, so in the simulation graph,After overcharging, it lasts 3-4 seconds.
As shown in figure 7 of the drawings,At a rate of 10mS, from 0V to 4.3V,The maximum amplitude of the overcharge is 3.33V, and the overcharge duration is about 421mS before the overcharge is restored to the preset state。
By changing the partial structure in the present embodiment, the same functions and effects can be obtained in the new embodiment.
The low-static-power-consumption power supply circuit has the advantages that the first amplifier is connected with a low-static-power-consumption circuit through a first NMOS tube, a first voltage division sampling resistor and a second voltage division sampling resistor are connected with the low-static-power-consumption circuit and generate feedback voltage, the comparator is connected with the low-static-power-consumption circuit through a fourth PMOS tube and compares the second reference voltage and the driving voltage generated inside the circuit to control the on and off of a switch controller of the fourth PMOS tube, the first amplifier outputs a first voltage signal based on the first reference voltage and the feedback voltage and outputs driving voltage through the first NMOS tube and the low-static-power-consumption circuit, the second PMOS tube generates and controls output voltage based on external input voltage and the driving voltage, and the power tube is controlled by modulating the driving voltage through the comparator circuit so as to improve the over-charging of the output voltage during slow starting under no-load and the over-load hot plug.
Fifth embodiment:
As shown in FIG. 9, an LDO circuit for improving output overcharging comprises a first amplifier, 、Circuit and switch with low static power consumption、、And comparator, and external power supplyPower supply, ground voltage GND, reference voltageAnd an external output voltage. The first amplifier is based on a first reference voltageAnd feedback voltageOutput voltage control signal。Is a common source amplifier with the source electrode grounded and the drain electrode connectedAnd the low static power consumption circuit, the grid is connected with the output end of the first amplifier and is based onAnd low static power consumption, and outputting the gate driving voltage。The grid electrode of the (E) is connected with the output end of the comparator, and the drain electrode is connected withAnd the source electrode is connected to the low static power consumption circuit.The source electrode of the transistor is connected with an external input voltage, the gate is connected to the low static power consumption circuit, drain access to the,Based on external input voltageAnd drive voltageControlling output voltageIs of a size of (a) and (b).Is connected with one end of the low static power consumption circuitIs provided with a drain electrode of (c),Is connected with the other end ofOne end of (1) is connected with a feedback voltage signal;The other end of which is grounded. A first amplifier,Bias current provided by low static power consumption circuit,、AndThe loop is formed into a negative feedback loop, and the negative feedback loop makes the reference voltageAnd feedback voltageUniform and pass throughAndSetting the output voltageThe output voltage is: . The comparator controls the switch Is provided for the opening and closing of (a). The low static power consumption circuit comprises、And a second amplifier, which is coupled to the first amplifier,Source access to (a)And is connected with an external input voltage, gate accessGate, drain access to、A source of (a); Source access to (a) And the drain of the second amplifier and the input terminal of the second amplifier and controlThe grid electrode is connected with the output end of the second amplifier, and the drain electrode is connected withDrain and of (2)Is formed on the drain electrode of the transistor. Wherein the second amplifier andForms a buffer based on the output voltageAnd controlIs connected to the drain follower output voltage of (a)And the static power consumption of the circuit is prevented from being increased due to the mismatching of the current mirror images.
In this embodiment, the comparator includes:、、、 And a current source . The saidIs grounded at the source and connected at the gateIs connected with the grid electrode and the drain electrode ofA gate drain is connected at the same time; Is grounded at the source and grounded at the drain A drain electrode of (2); Is connected with a second reference voltage Source electrode connected with current source;Is connected with the driving voltage by the grid electrodeSource electrode connected with current sourceDrain electrode is connected toThe drain electrode of the transistor is connected with a first voltage signal in parallel, a current sourceAccessing external input voltage. Wherein the method comprises the steps of、、、And a current sourceConstitute a five-tube amplifier based on the second reference voltageAnd drive voltageComparing and outputting voltage。
At idle loadIn the case of a slow-start-up,Rise slowly whenAfter exceeding the minimum working voltage, the negative feedback operational amplifier willAnd is pulled down to the full-on state of the power tube, at the moment,Voltage is lower thanComparator outputs high level, switchIn the off-state of the device,Is low in the number of times it is,Rise and follow upAscending whenThe voltage is about to be higher than the preset valueAt voltage, the negative feedback loop starts to pull up slowlyVoltage of the presetFor the output voltage set by the voltage dividing resistorThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, whenAbove the preset valueAt the time, since the power tube is regulatedThe overcharge condition is greatly improved.
Under the condition of no-load hot plug, when the saidAfter that, whenBelow a preset levelAfter that, the negative feedback is pulled downSo that the power tube is fully opened andFollowing upThe drop-off is carried out, at this time,Voltage is lower thanComparator outputs high level, switchIn the cut-off state whenWhen hot plug is powered on, the negative feedback loop starts to pull upVoltage whenThe voltage rises but not yet to limit the power tube regulationDuring (1) the comparator detectsVoltage is higher thanWhen the comparator outputs low level, the switchOpening to enableBecomes a grid-drain connected load, greatly enhancingGuan Lagao ACapability, i.e. fast toThe voltage is pulled up, so that the power tube is quickly regulated, and the output voltage overcharge is improved. Then whenAbove the preset valueWhen the power tube is regulatedThe overcharge condition is greatly improved. The no-load condition includes a condition in which no load is connected, and a condition in which the load is hung on the output voltage but the switch turns the load off.
As shown in figure 3 of the drawings,Under the condition of inconsistent residual electric heating plug-in speed,Is a variation of (c). When removingAfter that, the input capacitor is used for supplying power, and the static power consumption of the LDO under no load is small and unchanged, soThe hot plug is charged when the power is dropped at a constant speedWhen the residual power of the power supply is higher than 3.24V, the negative feedback operational amplifier is in a normal regulation state, soUnchanged, whenAt a voltage lower than 3.24V,Start to appear followingChange of drop, simulation effect graphAt the time of powering up at 3uS speed, atWhen falling within the range of 2.99-3.24V,Overcharging occurs andThe closer to the presetThe greater the overcharge, as seen in the above figures,Maximum overcharge was 3.4V (normalWhen the value of the voltage is =4.3v,=3.25V)。
As can be seen from the above-mentioned figures,Maximum overcharge was 3.4V (normalWhen the value of the voltage is =4.3v,=3.25V)。
As shown in figure 4 of the drawings,At a rate of 10mS, from 0V to 4.3V,The overcharge is small, the maximum amplitude of the overcharge is 3.256V, and the overcharge is recovered to the preset state after the duration time of the overcharge is about 27mS。
As shown in figure 6 of the drawings,The residual heat plugging condition of (2) is the same as that of FIG. 3, but the response speed of the circuit is slow because of not adding a comparison circuit, whenAfter overcharge, the power tube is in an off state untilFalls to a presetAfter that, the negative feedback releases the power tube, so in the simulation graph,After overcharging, it lasts 3-4 seconds.
As shown in figure 7 of the drawings,At a rate of 10mS, from 0V to 4.3V,The maximum amplitude of the overcharge is 3.33V, and the overcharge duration is about 421mS before the overcharge is restored to the preset state。
By changing the partial structure in the present embodiment, the same functions and effects can be obtained in the new embodiment.
The low-static-power-consumption power supply circuit has the advantages that the first amplifier is connected with a low-static-power-consumption circuit through a first NMOS tube, a first voltage division sampling resistor and a second voltage division sampling resistor are connected with the low-static-power-consumption circuit and generate feedback voltage, the comparator is connected with the low-static-power-consumption circuit through a fourth PMOS tube and compares the second reference voltage and the driving voltage generated inside the circuit to control the on and off of a switch controller of the fourth PMOS tube, the first amplifier outputs a first voltage signal based on the first reference voltage and the feedback voltage and outputs driving voltage through the first NMOS tube and the low-static-power-consumption circuit, the second PMOS tube generates and controls output voltage based on external input voltage and the driving voltage, and the power tube is controlled by modulating the driving voltage through the comparator circuit so as to improve the over-charging of the output voltage during slow starting under no-load and the over-load hot plug.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the technical scope of the present invention should be included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (8)
1. An LDO circuit for improving output overcharge comprises a first amplifier, a first NMOS tube, a second PMOS tube, a low static power consumption circuit, a fourth PMOS tube, a first voltage division sampling resistorAnd a second voltage division sampling resistorAnd an external input voltageFirst reference voltageAnd output voltageThe low-static-power-consumption PMOS transistor is characterized by further comprising a comparator, wherein the comparator is connected with the low-static-power-consumption circuit through a fourth PMOS transistor and is used for comparing based on a second reference voltage and a driving voltage generated in the circuit, the on and off of the fourth PMOS transistor are controlled, the first amplifier is used for outputting a first voltage signal based on the first reference voltage and the feedback voltage, the driving voltage is output through the first NMOS transistor and the low-static-power-consumption circuit, the second PMOS transistor is used for generating and controlling the output voltage based on an external input voltage and the driving voltage, the low-static-power-consumption circuit comprises a first PMOS transistor, a third PMOS transistor and a second amplifier, the source electrode of the first PMOS transistor is connected with the source electrode of the second PMOS transistor and is connected with the external input voltage, the drain electrode of the second PMOS transistor is connected with the gate electrode of the third PMOS transistor, the drain electrode of the third PMOS transistor is connected with the source electrode of the drain electrode of the third PMOS transistor, and the drain electrode of the fourth PMOS transistor is connected with the drain electrode of the fourth PMOS transistor.
2. The LDO circuit for improving output overcharge of claim 1, wherein the first NMOS tube is a common source amplifier, a source electrode is grounded, a drain electrode is connected with a drain electrode of a fourth PMOS tube and the low-static power consumption circuit, a grid electrode is connected with an output end of the first amplifier, a grid electrode driving voltage is output based on a first voltage signal and bias current provided by the low-static power consumption circuit, a source electrode of the second PMOS tube is connected with an external input voltage, a grid electrode is connected with the low-static power consumption circuit, and a drain electrode is connected with a first voltage division sampling resistor.
3. The LDO circuit of claim 1, wherein the second amplifier and the third PMOS transistor form a buffer, and the drain of the first PMOS transistor is controlled to follow the output voltage based on the output voltage, thereby avoiding an increase in static power consumption of the circuit due to current mirror mismatch.
4. The LDO circuit for improving output overcharge of claim 1, wherein a loop formed by the first amplifier, the first NMOS tube, the low static power consumption circuit, the second PMOS tube, the first sampling voltage dividing resistor and the second sampling voltage dividing resistor forms a negative feedback loop, one end of the first voltage dividing sampling resistor is connected to the drain electrodes of the low static power consumption circuit and the second PMOS tube, the other end of the first voltage dividing sampling resistor is connected with one end of the second voltage dividing sampling resistor and receives a feedback voltage signal, the other end of the second voltage dividing sampling resistor is grounded, the negative feedback loop enables a first reference voltage to be consistent with the feedback voltage, and an output voltage is set through the first sampling voltage dividing resistor and the second sampling voltage dividing resistor, and the output voltage is that:
。
5. The LDO circuit implementation method based on any one of claims 1 to 4 is characterized in that the comparator is connected with a low-static-power-consumption circuit through a fourth PMOS tube and controls the fourth PMOS tube to be turned on and off based on comparison of a second reference voltage and a driving voltage, the first amplifier outputs a first voltage signal based on the first reference voltage and a feedback voltage and outputs the driving voltage through a first NMOS tube and the low-static-power-consumption circuit, and the second PMOS tube generates and controls the output voltage based on the external input voltage and the driving voltage.
6. The method according to claim 5, wherein in the idle slow start, when the external input voltage exceeds the minimum operating voltage, the driving voltage is pulled down to the full-on state of the second PMOS transistor, the driving voltage is lower than the second reference voltage, and the comparator outputs a high level, the fourth PMOS transistor is in the off state, when the external input voltage is about to be higher than the output voltage set by the first sampling voltage dividing resistor and the second sampling voltage dividing resistor, the driving voltage is pulled up, the comparator detects that the driving voltage is higher than the second reference voltage, and then outputs a low level, and the fourth PMOS transistor is turned on, so that the second PMOS transistor is quickly regulated.
7. The LDO circuit implementation method based on any one of claims 1 to 4 is characterized in that the comparator is connected with a low-static-power-consumption circuit through a fourth PMOS tube and controls the fourth PMOS tube to be turned on and off based on comparison of a second reference voltage and a driving voltage, the first amplifier outputs a first voltage signal based on the first reference voltage and a feedback voltage and outputs the driving voltage through a first NMOS tube and the low-static-power-consumption circuit, and the second PMOS tube generates and controls the output voltage based on an external input voltage and the driving voltage.
8. The method for improving residual electric hot plug output overcharge according to claim 7, wherein under the condition of no-load hot plug external input voltage pulling, when the external input voltage is lower than the output voltage set through the first sampling voltage dividing resistor and the second sampling voltage dividing resistor, the driving voltage is pulled down to be fully on by the second PMOS tube, the driving voltage is lower than the second reference voltage, the comparator outputs a high level, the fourth PMOS tube is in a cut-off state, when the external input voltage is subjected to hot plug power-on, the driving voltage is pulled up to be higher than the second reference voltage, the comparator detects the rear output low level, and the fourth PMOS tube is started, so that the second PMOS tube is quickly regulated, and the output voltage overcharge is improved.
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| CN119200735B true CN119200735B (en) | 2025-03-21 |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103677058A (en) * | 2012-09-07 | 2014-03-26 | 精工电子有限公司 | Voltage regulator |
| CN116501119A (en) * | 2023-04-25 | 2023-07-28 | 无锡裕芯电子科技有限公司 | LDO circuit with static power consumption |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005301439A (en) * | 2004-04-07 | 2005-10-27 | Ricoh Co Ltd | Voltage regulator |
| JP2007219795A (en) * | 2006-02-16 | 2007-08-30 | Matsushita Electric Ind Co Ltd | Voltage regulator |
| JP6008678B2 (en) * | 2012-09-28 | 2016-10-19 | エスアイアイ・セミコンダクタ株式会社 | Voltage regulator |
| JP6170354B2 (en) * | 2013-06-25 | 2017-07-26 | エスアイアイ・セミコンダクタ株式会社 | Voltage regulator |
| CN208608726U (en) * | 2018-08-09 | 2019-03-15 | 厦门安斯通微电子技术有限公司 | A kind of LDO output over-voltage protection structure not increasing quiescent current |
| CN118466658A (en) * | 2024-05-27 | 2024-08-09 | 宁波隔空智能科技有限公司 | Ultralow-power-consumption LDO circuit for solving overshoot of output voltage during power-up and electronic terminal applied by ultralow-power-consumption LDO circuit |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103677058A (en) * | 2012-09-07 | 2014-03-26 | 精工电子有限公司 | Voltage regulator |
| CN116501119A (en) * | 2023-04-25 | 2023-07-28 | 无锡裕芯电子科技有限公司 | LDO circuit with static power consumption |
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