TWI492505B - Power management circuit, and control circuit and control method thereof - Google Patents

Description

Power supply and control circuit and control method thereof

The invention relates to a power supply device and a control circuit and a control method thereof, in particular to a power supply device capable of adjusting an output voltage correspondingly according to a difference in power supply capability of an input terminal, thereby improving overall power supply efficiency and Control circuit and control method.

Please refer to Figure 1A and compare Figure 1B. Figure 1A shows a schematic diagram of a prior art power supply. Figure 1B shows an embodiment of the first operational circuit of the prior art. The power supply 10 can convert an input voltage VIN provided by an input terminal IN to an output voltage VSYS at an output terminal SYS, and charge a battery BAT from the output terminal SYS. The input terminal IN can be coupled to an external power source 18 to receive power from the external power source 18 and generate an input current Iin at the input terminal IN. The output SYS can be coupled to a load 19 to provide an output voltage VSYS from the output SYS to the load 19. As shown in FIG. 1A, the power supply 10 includes a first linear adjustment circuit 11 and a second linear adjustment circuit 12. The first linear adjustment circuit 11 and a second linear adjustment circuit 12 are, for example but not limited to, a low-dropout regulator (LDO). The first linear adjustment circuit 11 includes a first switch 111 and a first operation circuit 112. The first operating circuit 112 is configured to generate a first operational signal S1' for controlling the first switch 111, thereby controlling the first switch 111. As shown in FIG. 1B, the first operational circuit 112 has an error amplifier EA1'. The error amplifier EA1' compares the feedback signal FB1' (representing information related to the output voltage VSYS) with a reference voltage REF to generate a An operation signal S1' is used to control the operation of the first switch 111 to be constantly turned on and to operate in the linear region of the transistor. power supply The supplier 10 can further include a first voltage detecting component 16. The first voltage detecting component 16 is, for example but not limited to, a voltage dividing circuit that generates a feedback signal FB1' representing information related to the output voltage VSYS. One end of the second linear adjustment circuit 12 is electrically connected to the output terminal SYS and the other end thereof is electrically connected to the battery BAT. The second linear adjustment circuit 12 includes a second switch 121 and a second operation circuit 122. The second switch 121 is electrically connected between the output terminal SYS and the battery BAT. When the input terminal IN is powered by the external power source 18, the power provided by the external power source 18 can provide a charging current ICHG to the battery BAT via the output terminal SYS to charge the battery BAT. At this time, the second operation circuit 122 is generated according to the feedback signal FB2' (relevant information representing the battery voltage VBAT of the battery BAT) and the feedback signal FB3' (representing information related to the charging current ICHG through the second switch 121). A second operation signal S2' is used to control the second switch 121 to be constantly turned on and operate in a linear region of the transistor, thereby controlling the output terminal SYS to charge the battery BAT. The power supply 10 can further include a second voltage detecting component 17. The second voltage detecting component 17 is, for example but not limited to, a voltage dividing circuit that generates a feedback signal FB2' representing information about the battery voltage VBAT.

In this prior art, the reference voltage REF shown in FIG. 1B is a fixed value and cannot be adjusted. Therefore, correspondingly, the level of the output voltage VSYS is also a fixed value and cannot be adjusted. However, since the first linear adjustment circuit 11 and the second linear adjustment circuit 12 are both linear adjustment circuits, wherein the switches 111 and 112 are always turned on and operate in the linear region of the transistor, the level of the output voltage VSYS is set. The dilemma. When the level of the output voltage VSYS is closer to the level of the battery voltage VBAT, although the power loss from the output terminal SYS to the battery BAT is small, the power loss from the input terminal IN to the output terminal SYS becomes large. When the level of the output voltage VSYS is closer to the level of the input voltage VIN, although the power loss from the input terminal IN to the output terminal SYS is small, the power loss from the output terminal SYS to the battery BAT becomes large. Therefore, in the prior art, regardless of the level of the output voltage VSYS being closer to the level of the battery voltage VBAT or the level of the input voltage VIN, power loss occurs. And cause overall energy waste.

In view of this, the present invention is directed to the above-mentioned deficiencies of the prior art, and proposes a power supply device and its control circuit and control capable of adjusting the output voltage correspondingly according to the difference in power supply capability of the input terminal, thereby improving the overall power supply efficiency. method.

In one aspect, the present invention provides a power supply for converting an input voltage provided by an input to an output voltage at an output, and for charging a battery from the output. The power supply includes: a power path management circuit, one end of which is electrically connected to the output end, and the other end is electrically connected to the battery to control the output end to charge a current of the battery; a first switch is coupled to the first switch Between the input terminal and the output terminal; a first operating circuit generates a first operation signal according to the output voltage and an adjustment signal, thereby controlling the operation of the first switch, the first operation circuit includes: a first error amplifier, wherein the first feedback signal is compared with a reference voltage of the output voltage to generate the first operation signal; and a reference voltage adjustment circuit, according to the adjustment signal, Adjusting the reference voltage; and detecting a circuit for determining a power supply capability of the input terminal to generate the adjustment signal.

In a preferred embodiment, the detecting circuit has at least one of the following: (1) a connection end connected to the input end; (2) a data processing (DP) end; (3) a data memorizing (DM) end; and/or (4) an identification (ID) end, and the detecting circuit is integrated by one or more of the following methods to determine the power supply capability of the input end To generate the adjustment signal: (1) directly detecting the power supply capability of the input terminal; (2) identifying according to the data received by the data processing terminal and/or a data memory terminal; and/or (3) according to the The identification end receives the identity data of an external power source electrically connected to the input terminal for identification.

In a preferred embodiment, the reference voltage adjustment circuit includes one of the following circuits: a digital analog conversion circuit, a look-up table circuit, an amplification circuit, or a sample and hold circuit.

In a preferred embodiment, the reference voltage adjustment circuit includes: an adder that adds a second feedback signal related to the voltage of the battery and a safety difference or its associated signal to generate a And a selection circuit, according to the adjustment signal, when the adjustment signal indicates that the power supply capability of the input terminal is relatively strong, selecting a first preset voltage level or its associated signal as the reference voltage; When the adjustment signal indicates that the power supply capability of the input terminal is relatively weak, the output of the adder is selected as the reference voltage.

In a preferred embodiment, the reference voltage adjustment circuit includes: an adder that adds a second feedback signal related to the voltage of the battery and a safety difference or its associated signal to generate a And a selection circuit, when the adjustment signal indicates that the power supply capability of the input terminal is relatively strong, determining a first preset voltage level or a related signal as the reference voltage; when the adjustment signal indicates the When the power supply capability of the input terminal is relatively weak, the higher one is selected between (1) a second preset voltage level or its associated signal, or (2) the output of the adder, (1) and (2) above. As a reference voltage.

In a preferred embodiment, the power path management circuit includes: a second switch electrically connected between the output terminal and the battery; and a second operating circuit based on at least the battery voltage or its associated signal And the charging current or its associated signal generates a second operation signal to control the second switch to control the charging current.

In a preferred embodiment, the first operating circuit and the first switch form a first low-dropout regulator (LDO) or a first switched power stage, and the first The second operational circuit and the second switch form a second low dropout linear regulator or a second switched power stage.

In another aspect, the present invention also provides a control circuit for a power supply for controlling a first switch electrically connected between an input terminal and an output terminal, and controlling the electrical connection to the output terminal and a battery a second switch for converting an input voltage provided by the input terminal to an output voltage, and charging a battery from the output terminal, the control circuit comprising: a first operating circuit, at least according to The output voltage is adjusted with a signal Generating a first operation signal for controlling the operation of the first switch, the first operation circuit comprising: a first error amplifier, the first error amplifier correlating a first feedback signal and a reference related to the output voltage Comparing voltages to generate the first operation signal; and a reference voltage adjustment circuit for adjusting the reference voltage according to the adjustment signal; and a detecting circuit for determining a power supply capability of the input terminal to generate the adjustment Signal.

In a preferred embodiment, the control circuit of the power supply further includes: a second operating circuit, generating a second operation signal according to at least the battery voltage or its associated signal and the charging current or its associated signal To control the second switch to control the charging current.

In another aspect, the present invention also provides a power supply control method, comprising the following steps: (A) converting an input voltage provided by an input terminal into an output voltage at an output terminal, and from the output terminal (B) detecting a power supply capability of the input terminal; (C) generating an adjustment signal according to the power supply capability of the input terminal; and (D) adjusting the output voltage according to the adjustment signal.

In a preferred embodiment, the step (A) includes: (A1) generating a first feedback signal according to the output voltage; and (A2) comparing the first feedback signal with a reference voltage to borrow The level of the output voltage is adjusted by the feedback control mode to the level corresponding to the reference voltage.

In a preferred embodiment, a first switch is electrically connected between the input end and the output end, a second switch is electrically connected between the output end and the battery, and step (A2) further comprises: The comparison between the first feedback signal and the reference voltage controls the first switch or the second switch.

In a preferred embodiment, the step (D) comprises: adjusting the output voltage in a two-stage, multi-stage or continuous manner according to the adjustment signal.

In a preferred embodiment, the step (D) includes: when the adjustment signal indicates that the power supply capability of the input terminal is relatively strong, the output voltage is a first fixed value and the fixed value is relatively close to the The level of the input voltage; when the adjustment signal indicates the power supply of the input When the capability is relatively weak, the output voltage is one of the following: (1) the output voltage is a second fixed value and the fixed value is relatively close to the level of the battery voltage; (2) the output voltage is The power supply capability of the input is changed; (3) the output voltage is determined by the sum of the battery voltage and a safety difference; or (4) the output voltage is (a) the battery voltage and the safety difference Vos Addition, or (b) a predetermined voltage level, which is determined by the higher level between (a) and (b) above.

The purpose, technical content, features and effects achieved by the present invention will be more readily understood by the detailed description of the embodiments.

[study]

10‧‧‧Study power supply

11‧‧‧The first linear adjustment circuit

111‧‧‧The first switch

112‧‧‧The first operational circuit

12‧‧‧The second linear adjustment circuit

121‧‧‧The second switch

122‧‧‧The second operating circuit

16‧‧‧The first voltage detecting component

17‧‧‧ Known second voltage detecting component

18‧‧‧Issue external power supply

19‧‧‧Study load

EA1'‧‧‧Custom Error Amplifier

FB1’~FB3’‧‧‧Custom feedback signal

REF‧‧‧Learning reference voltage

S1’‧‧‧The first operational signal

S2’‧‧‧The second operational signal

〔this invention〕

20‧‧‧Power supply

21‧‧‧First switch

22‧‧‧Power Path Management Circuit

221‧‧‧second switch

222‧‧‧Second operation circuit

23‧‧‧Detection circuit

24‧‧‧reference voltage adjustment circuit

241‧‧‧Adder

242‧‧‧Selection circuit

25‧‧‧First operating circuit

26‧‧‧First voltage detecting component

27‧‧‧Second voltage detecting component

28‧‧‧External power supply

29‧‧‧Load

30‧‧‧Control circuit

AL‧‧‧Adjustment signal

BAT‧‧‧Battery

DP‧‧‧ data processing end

DM‧‧‧data memory

EA1‧‧‧Error Amplifier

FB1~FB3‧‧‧Response signal

ICHG‧‧‧Charging current

ID‧‧‧ Identification end

Iin‧‧‧ input current

IN‧‧‧ input

ISYS‧‧‧ output current

L1‧‧‧first inductance

L2‧‧‧second inductance

M1, M2‧‧‧ power transistor switch

M5‧‧‧ first upper bridge switch

M6‧‧‧First lower bridge switch

M7‧‧‧Second upper bridge switch

M8‧‧‧Second lower bridge switch

Q1, Q2‧‧‧ power transistor switch

Q3, Q4‧‧‧Powered transistor switch with adjustable parasitic diode polarity

ST1~ST4, ST41~ST44‧‧‧ steps

SYS‧‧‧ output

S1‧‧‧ first operation signal

S2‧‧‧second operation signal

VA, VB‧‧‧Preset voltage level

VBAT‧‧‧ battery voltage

VIN‧‧‧ input voltage

Vos‧‧‧Safety Difference

Vref1‧‧‧reference voltage

VSYS‧‧‧ output voltage

Figure 1A shows a schematic diagram of a prior art power supply.

Figure 1B shows an embodiment of the first operational circuit of the prior art.

Fig. 2 is a view showing a power supply of an embodiment of the present invention.

Fig. 3A shows an embodiment of the power path management circuit of the present invention.

FIG. 3B shows an embodiment of the first voltage detecting element and the second voltage detecting element.

Figures 4A-4C show several embodiments when the first switch is a power transistor switch.

Figures 5A-5C show several embodiments when the second switch is a power transistor switch.

Figures 6A-6H show that when the first switch is a switched power stage, the first switch can be a synchronous or asynchronous step-down, boost, back-pressure, or buck-boost switching power stage.

Figures 7A-7H show that when the second switch is a switched power stage, the second switch can be a synchronous or asynchronous step-down, boost, back-pressure, or buck-boost switching power stage.

Figure 8 shows an embodiment of the first operational circuit of the present invention.

Figure 9 shows an embodiment of how to adjust the target level of the output voltage VSYS.

Figures 10A-10B show two embodiments of adjusting the output voltage VSYS stepwise or continuously depending on the power supply capability of the input terminal IN.

Figures 11-12 show two other embodiments of how to adjust the target level of the output voltage VSYS.

Figures 13-14 show two other embodiments of the first operational circuit of the present invention.

Fig. 15 is a flow chart showing a control method of a power supply device according to an embodiment of the present invention.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only directions referring to the additional drawings. The drawings in the present invention are intended to illustrate the functional relationship between the various devices and the various elements, and the shapes, thicknesses, and widths are not drawn to scale.

Please refer to FIG. 2, which shows a schematic diagram of a power supply according to an embodiment of the present invention. The power supply 20 can convert an input voltage VIN provided by an input terminal IN to an output voltage VSYS to an output terminal SYS, and charge a battery BAT from the output terminal SYS. The input terminal IN can be coupled to an external power source 28 to receive power from the external power source 28 to generate an input current Iin at the input terminal IN. The output SYS can be coupled to a load 29 to provide an output current ISYS and an output voltage VSYS from the output SYS to the load 29. The power supply 20 includes a first switch 21, a first operating circuit 25, a power path management circuit 22, and a detecting circuit 23. The first switch 21 is coupled between the input terminal IN and the output terminal SYS. The first operation circuit 25 is configured to generate a first operation signal S1 for controlling the first switch 21, thereby controlling the first switch 21. The first operation circuit 25 is based on the feedback signal FB1 representing the related information of the output voltage VSYS (for example, the output voltage VSYS itself or its voltage division signal) and an adjustment signal AL generated by the detection circuit. The first operation signal S1 is generated; how the operation circuit 25 generates the details of the first operation signal S1 and the technical characteristics of the adjustment signal AL are detailed later.

Please refer to FIG. 3A, which shows an embodiment of the power path management circuit of the present invention. One end of the power path management circuit 22 is electrically connected to the output terminal SYS and the other end thereof is electrically connected to the battery BAT. The power path management circuit 22 includes a second switch 221 and a second operating circuit 222, wherein the second switch 221 is electrically connected between the output terminal SYS and the battery BAT. When the input terminal IN is powered by the external power source 28, the power provided by the external power source 28 can provide a charging current ICHG to the battery BAT via the output terminal SYS to charge the battery BAT. At this time, the second operation circuit 222 generates a first according to the feedback signal FB2 (representative information representing the battery voltage VBAT of the battery BAT) and the feedback signal FB3 (representing information related to the charging current ICHG through the second switch 221). The second operation signal S2 controls the second switch 221, thereby controlling the charging of the battery BAT by the output terminal SYS.

In addition to the above arrangement, please refer to FIG. 2, or it may be arranged that: the first operation circuit 25 is based on the feedback signal FB1 (representing information related to the output voltage VSYS) and the feedback signal FB2 (representing the battery voltage VBAT of the battery BAT). Related information, indicated by a broken line) and the adjustment signal AL, the first operation signal S1 is generated to control the first switch 21; the second operation circuit 222 is only based on the feedback signal FB3 (representing the correlation of the charging current ICHG through the second switch 221) Information), a second operation signal S2 is generated to control the second switch 221. Alternatively, the second operation circuit 222 can generate the second operation signal S2 to control the second switch 221 according to the feedback signal FB2 and the feedback signal FB3.

In another embodiment, it may be arranged that the first operation circuit 25 generates the first operation signal S1 to control the first only according to the feedback signal FB2 (representing the information of the battery voltage VBAT of the battery BAT, indicated by a broken line). The second operation circuit 222 is based on the feedback signal FB1 (representing the information related to the output voltage VSYS, indicated by a broken line), the feedback signal FB3 (representing information related to the charging current ICHG through the second switch 221), and the adjustment signal. AL The second operation signal S2 is generated to control the second switch 221.

The same points of the above embodiments are: adjusting the target level of the output voltage VSYS according to the adjustment signal AL, the details of which are detailed later.

In a preferred embodiment, the power supply 20 can selectively include the first voltage detecting component 26 and the second voltage detecting component 27 to detect the output voltage VSYS and the battery voltage VBAT; but if the output voltage VSYS and the battery The level of the voltage VBAT can be processed by the circuit, and the first voltage detecting component 26 and the second voltage detecting component 27 can be omitted. Please refer to FIG. 3B , which shows an embodiment of the first voltage detecting component 26 and the second voltage detecting component 27 , wherein the first voltage detecting component 26 and the second voltage detecting component 27 can be, for example, a resistor-divided piezoelectric component. The circuit takes the partial voltage on the resistor as the feedback signal FB1 and the feedback signal FB2.

In a preferred embodiment, the feedback signal FB3 is obtained, for example, but not limited to, by sensing a charging current ICHG of the second switch 221 via a current sensing component (not shown in FIG. 2); the current sensing component For example, but not limited to, a detecting transistor connected in parallel with the second switch 221 or a detecting resistor connected in series with the path of the charging current ICHG can be implemented in various ways, and the present invention is not limited to being used. any type. The technical details of the feedback control of the feedback signal FB3 are well known to those skilled in the art and will not be described in detail herein.

Please refer to FIG. 4A-4C, which shows several embodiments when the first switch is a power transistor switch, and please refer to FIG. 5A-5C, which shows several when the second switch is a power transistor switch. Example. In a preferred embodiment, the first switch 21 is, for example but not limited to, a first power transistor switch Q1 (as shown in FIG. 4A), and the second switch 221 is, for example but not limited to, a second power. Transistor switch Q2 (as shown in Figure 5A). The first power transistor switch Q1 and the second power transistor switch Q2 are, for example but not limited to, NMOS transistors or PMOS transistors. The first switch 21 and the first operating circuit 25 are, for example but not limited to, a first low-dropout regulator (LDO), a second switch 221 and a second operating circuit 222. For example, but not limited to, a second low drop drop regulator (LDO) can be constructed.

If it is considered to avoid current backflow, the first switch 21 and the second switch 221 can adopt the power transistor switches Q3 and Q4 of the adjustable parasitic diode polarity, as shown in FIGS. 4B and 5B, respectively, having polarity. Parallel diode with adjustable direction. Alternatively, the first switch 21 and the second switch 221 may be respectively combined by two strings of connected transistors, each having a parasitic diode of opposite polarity directions, respectively, M1 and Q1 as shown in FIG. 4C, and 5C, respectively. M2 and Q2 shown in the figure. That is, the first operation signal S1 sent by the first operation circuit 25 or the second operation signal S2 sent by the second operation circuit 222 simultaneously controls the two transistors (or at least controls the parasitic diode to be opposite to the current direction). Transistor).

In addition to forming a low dropout linear regulator or other linear circuit, in other embodiments, the first switch 21 is, for example but not limited to, a power transistor switch that can be a first switched power stage, and the second switch 221, for example However, it is not limited to a power transistor switch that can be a second switched power stage. The first switched power stage can be, for example but not limited to, a synchronous or non-synchronous buck, boost, back-pressure, or buck-boost switching power conversion circuit, as shown in Figures 6A-6H. For example, the first switched power stage may include a first upper bridge switch M5, a first lower bridge switch M6, and a first inductor L1, as shown in FIG. 6A. The second switched power stage can be, for example but not limited to, a synchronous or non-synchronous buck, boost, back-pressure, or buck-boost switching power conversion circuit, as shown in Figures 7A-7H. For example, the second switched power stage can include a second upper bridge switch M7, a second lower bridge switch M8, and a second inductor L2, as shown in FIG. 7A. Correspondingly, the first operating circuit 25 can be, for example but not limited to, a first switching regulator, and the second operating circuit 222 can be, for example but not limited to, a second switching regulator. The technical details of how the first switching regulator generates the first operational signal S1 and the second switched regulator generates the second operational signal S2 are well known to those skilled in the art and will not be described in detail herein.

The following example illustrates how the present invention changes the target level of the output voltage VSYS according to the adjustment signal AL. Please refer to FIG. 8 , which shows the first operation circuit 25 of the present invention. One embodiment. As shown in the figure, in the embodiment of FIG. 8, the detecting circuit 23 is configured to determine the power supply capability of the input terminal IN (that is, the power supply capability of the external power source 28 in FIG. 2), and output the power supply related to the input terminal IN. The ability to adjust the signal AL. The adjustment signal AL can be a one-digit or multi-digit digital signal, or an analog signal. The input detection circuit 23 can determine the power supply capability of the input terminal IN according to, for example but not limited to, one of the following ways: (1) directly detecting the power supply capability of the input terminal IN, for example, extracting current from the input terminal IN. After detecting the change of the input voltage VIN; and/or (2) identifying according to data received by a Data Processing (DP) terminal and/or a Data Memorizing (DM) terminal; and / Or (3) identifying the identity data received by the Identifying (ID) terminal with respect to the external power source 28. If only one of the above methods is used, other unnecessary receiving ends may be omitted (that is, the input detecting circuit 23 is in the "connecting end, the DP end, the DM end, and the ID end connected to the input terminal IN", and is not required. All available).

In the embodiment of FIG. 8, the first operational circuit 25 includes a reference voltage adjustment circuit 24 and an error amplifier EA1. The error amplifier EA1 compares the feedback signal FB1 (representing information about the output voltage VSYS, for example, the output voltage VSYS itself or its divided signal) with an adjustable reference voltage Vref1 to generate the first operational signal S1, Thereby the first switch 21 is controlled (see Fig. 2). According to the principle of feedback control, when the circuit is balanced, the two input terminals of the error amplifier EA1 will be at the same level (assuming that the internal bias of the error amplifier EA1 is ignored), so the reference voltage adjustment circuit 24 is based on the input detection circuit 23. By outputting the (adjustment signal AL) and adjusting the reference voltage Vref1, the level of the feedback signal FB1 can be controlled, and the target level of the output voltage VSYS can be adjusted to the level corresponding to the reference voltage Vref1. The adjustment signal AL outputted by the input detection circuit 23 can be, for example, a digital signal, and the reference voltage adjustment circuit 24 can be, for example, a digital analog conversion circuit or a mapping circuit, which generates a digital signal according to the input digital signal. Corresponding analog output; or the adjustment signal AL output by the input detection circuit 23 can be, for example, an analog signal, and the reference voltage adjustment circuit 24 can be, for example It is an amplifying circuit or a sample-and-hold circuit. The details of the digital analog conversion circuit, the look-up table circuit, the amplification circuit, and the sample-and-hold circuit are well known to those skilled in the art and will not be described herein.

Referring to FIG. 8 and FIG. 9 , FIG. 9 shows an embodiment of how to adjust the target level of the output voltage VSYS. In this embodiment, when the power supply capability of the input terminal IN is strong, the output voltage VSYS is output. The target level is adjusted to a higher level, and when the power supply capability of the input terminal IN is weak, the target level of the output voltage VSYS is adjusted to a lower level. The illustrated output voltage VSYS has only two target levels, but of course it can also be designed into multiple target levels and adjusted stepwise or continuously according to the power supply capability of the input terminal IN, as shown in Figures 10A and 10B. Show. In the article, "the power supply capability of the input terminal IN is strong" means that the input terminal IN can supply a larger amount of current and the voltage level does not decrease significantly. "The power supply capability of the input terminal IN is weak" means the opposite situation. As for how much current is considered to be "a larger amount", the visual application needs to be defined by the line.

Figure 11 shows another embodiment of how to adjust the target level of the output voltage VSYS. In this embodiment, when the power supply capability of the input terminal IN is strong, the target level of the output voltage VSYS is adjusted to a higher level. Quasi (preset voltage level VA), when the power supply capability of the input terminal IN is weak, the target bit criterion of the output voltage VSYS changes with the battery voltage VBAT, and there is a safety difference Vos between the output voltage VSYS and the battery voltage VBAT (That is, the output voltage VSYS is determined by the sum of the battery voltage VBAT and a safety difference Vos).

Figure 12 shows another embodiment of how to adjust the target level of the output voltage VSYS. In this embodiment, when the power supply capability of the input terminal IN is strong, the target level of the output voltage VSYS is adjusted to a higher level. Quasi (preset voltage level VA), when the power supply capability of the input terminal IN is weak, the output voltage VSYS is composed of (1) the sum of the battery voltage VBAT and the safety difference Vos, or (2) a predetermined voltage level. Quasi-VB, the higher the level between (1) and (2) is determined. The purpose of this arrangement is to make the output voltage VSYS at least not lower than the preset voltage level VB to ensure that the load 29 (see Figure 2) that accepts the output voltage VSYS can operate normally.

Corresponding to the embodiment of FIGS. 11 and 12, in FIG. 8, the reference voltage adjustment circuit 24 can additionally receive the feedback signal FB2 (relevant information representing the battery voltage VBAT of the battery BAT), and according to the adjustment signal AL and feedback The signal FB2 determines how to adjust the reference voltage Vref1. In detail, FIG. 13 shows the first operation circuit 25 and the reference voltage adjustment circuit 24 which can cooperate with the embodiment of FIG. 11, wherein the first operation circuit 25 includes the reference voltage adjustment circuit 24 and the error amplifier EA1, and the reference voltage The adjustment circuit 24 includes an adder 241 and a selection circuit 242. The adder 241 adds the feedback signal FB2 and the safety difference value Vos or its associated signal, and the selection circuit 242 determines whether to select the preset voltage level VA or its associated signal or the adder 241 according to the adjustment signal AL. The output is used as the reference voltage Vref1. The above "or its related signal" is because: if the feedback signal FB2 is the partial voltage of the battery voltage VBAT, the safety difference Vos should also take the corresponding proportional value (ie "correlated signal") before the feedback signal FB2 is added; if the feedback signal FB1 is the voltage division of the output voltage VSYS, the preset voltage level VA should also be input to the selection circuit 242 after taking the corresponding proportional value (ie, "correlated signal").

Fig. 14 shows a first operation circuit 25 and a reference voltage adjustment circuit 24 which can be combined with the embodiment of Fig. 12. This embodiment is similar to the embodiment of Fig. 13, except that the selection circuit 242 determines whether or not to use the adjustment signal AL. The preset voltage level VA or its associated signal is used as the reference voltage Vref1; if not, the higher one is selected as the reference voltage Vref1 in the preset voltage level VB or its associated signal and the output of the adder 241.

The above embodiment is described by taking the first operation circuit 25 as the feedback signal FB1 and the adjustment signal AL; if the second operation circuit 222 (refer to FIG. 3A) receives the feedback signal FB1 and the adjustment signal AL, it is also available. A similar approach is implemented and will not be repeated.

Please refer to Figure 15 again. Fig. 15 is a flow chart showing a control method of a power supply device according to an embodiment of the present invention. First, the power supply capability of the input terminal IN is detected (step ST1), and the power supply capability of the input terminal IN is judged to be strong (step ST2). If the power supply capability of the input terminal IN is strong, the output voltage VSYS can be set to a fixed value and close to the input voltage VIN (step ST3), as shown in steps 9, 11, Figure 12 shows the higher VSYS. If the power supply capability of the input terminal IN is weak, proceed to step ST4, and select one of ST41 to ST44: Step ST41: Set the output voltage VSYS to a fixed value and approach the battery voltage (as shown by the lower VSYS in FIG. 9). Or step ST42: the output voltage VSYS changes with the power supply capability of the input terminal IN (as shown by VSYS in FIGS. 10A-10B); or step ST43: the output voltage VSYS is summed by the battery voltage VBAT and the safety difference Vos To determine (as shown in the lower VSYS diagram in Figure 11); or step ST44: the output voltage VSYS is the sum of the battery voltage VBAT and the safety difference Vos, or the preset voltage level VB, the level between the two The winner decides (as shown in the lower VSYS in Figure 12).

In one embodiment, the first operational circuit 25, the power path management circuit 22, and the detection circuit 23 may be integrated into a control circuit 30 in whole or in part by integrated circuit fabrication techniques (see FIG. 2).

The feature and advantage of the present invention is that the reference voltage Vref1 can be adjusted according to whether the power supply capability of the input terminal IN is strong or weak, and accordingly the output voltage VSYS is adjusted correspondingly to improve the overall power supply efficiency.

The present invention has been described with reference to the preferred embodiments thereof, and the present invention is not intended to limit the scope of the present invention. In the same spirit of the invention, various equivalent changes can be conceived by those skilled in the art. All such modifications may be made in accordance with the teachings of the present invention, and the scope of the present invention should be construed to cover the above and other equivalents. In addition, any embodiment of the present invention is not required to achieve all of the objects or advantages, and therefore, any one of the claims is not limited thereto.

20‧‧‧Power supply

21‧‧‧First switch

22‧‧‧Power Path Management Circuit

23‧‧‧Detection circuit

25‧‧‧First operating circuit

26‧‧‧First voltage detecting component

27‧‧‧Second voltage detecting component

28‧‧‧External power supply

29‧‧‧Load

30‧‧‧Control circuit

AL‧‧‧Adjustment signal

BAT‧‧‧Battery

DP‧‧‧ data processing end

DM‧‧‧data memory

FB1~FB3‧‧‧Response signal

ICHG‧‧‧Charging current

ID‧‧‧ Identification end

Iin‧‧‧ input current

IN‧‧‧ input

ISYS‧‧‧ output current

SYS‧‧‧ output

S1‧‧‧ first operation signal

S2‧‧‧second operation signal

VBAT‧‧‧ battery voltage

VIN‧‧‧ input voltage

VSYS‧‧‧ output voltage

Claims (18)

A power supply device for converting an input voltage provided by an input terminal to an output voltage for outputting an output terminal, and for charging a battery from the output terminal, the power supply device comprising: a power path management circuit, One end is electrically connected to the output end, and the other end is electrically connected to the battery to control the output end to charge a current of the battery; a first switch is coupled between the input end and the output end; a first operating circuit, based on the output voltage and an adjustment signal, generating a first operation signal for controlling operation of the first switch, the first operation circuit comprising: a first error amplifier, the first error amplifier Comparing a first feedback signal related to the output voltage with a reference voltage to generate the first operation signal; and a reference voltage adjustment circuit, adjusting the reference voltage according to the adjustment signal; and a detection circuit For determining the power supply capability of one of the inputs, the adjustment signal is generated. The power supply device of claim 1, wherein the detecting circuit has at least one of the following: (1) a connection end connected to the input end; (2) a data processing (DP) (3) a Data Memorizing (DM) end; and/or (4) an identification (ID) end, and the detecting circuit is determined by one or more of the following methods: The power supply capability of the input terminal to generate the adjustment signal: (1) directly detecting the power supply capability of the input terminal; (2) identifying the data received by the data processing terminal and/or a data memory terminal; and/or (3) According to the identification data received by the identification terminal, an external power source electrically connected to the input terminal To identify. The power supply device of claim 1, wherein the reference voltage adjustment circuit comprises one of the following circuits: a digital analog conversion circuit, a look-up table circuit, an amplification circuit, or a sample and hold circuit. The power supply device of claim 1, wherein the reference voltage adjustment circuit comprises: an adder, the second feedback signal related to the voltage of the battery and a safety difference value or a related signal thereof Adding to generate a total signal; and a selection circuit, according to the adjustment signal, when the adjustment signal indicates that the power supply capability of the input terminal is relatively strong, selecting a first preset voltage level or its associated signal as The reference voltage; when the adjustment signal indicates that the power supply capability of the input terminal is relatively weak, the output of the adder is selected as the reference voltage. The power supply device of claim 1, wherein the reference voltage adjustment circuit comprises: an adder, the second feedback signal related to the voltage of the battery and a safety difference value or a related signal thereof Adding to generate a total signal; and a selection circuit, when the adjustment signal indicates that the power supply capability of the input terminal is relatively strong, determining a first predetermined voltage level or its associated signal as the reference voltage; The adjustment signal indicates that the power supply capability of the input terminal is relatively weak, in (1) a second preset voltage level or its associated signal, or (2) the output of the adder, above (1) (2) The higher one is selected as the reference voltage. The power supply device of claim 1, wherein the power path management circuit comprises: a second switch electrically connected between the output terminal and the battery; and a second operation circuit, at least according to the battery The voltage or its associated signal and the charging current or its associated signal generate a second operational signal to control the second switch and thereby control This charging current is made. The power supply device of claim 6, wherein the first operating circuit and the first switch constitute a first low-dropout regulator (LDO) or a first switching power And the second operating circuit and the second switch form a second low dropout linear regulator or a second switched power stage. A control circuit for a power supply for controlling a first switch electrically connected between an input terminal and an output terminal, and controlling a second switch electrically connected between the output terminal and a battery to input the input The terminal provides one input voltage to be converted into an output voltage at the output end, and charges a battery from the output end, the control circuit includes: a first operating circuit, at least according to the output voltage and an adjustment signal, generating a first An operation signal for controlling operation of the first switch, the first operation circuit comprising: a first error amplifier, the first error amplifier comparing a first feedback signal associated with the output voltage with a reference voltage And generating a first operation signal; and a reference voltage adjustment circuit, adjusting the reference voltage according to the adjustment signal; and a detection circuit for determining a power supply capability of the input terminal to generate the adjustment signal. The control circuit of the power supply device of claim 8, wherein the detecting circuit has at least one of the following: (1) a connection end connected to the input end; (2) a data processing (Data Processing) , DP); (3) a Data Memorizing (DM) end; and/or (4) an Identifying (ID) end, and the detecting circuit is integrated by one or more of the following means To determine the power supply capability of the input terminal to generate the adjustment signal: (1) directly detecting the power supply capability of the input terminal; (2) identifying according to the data received by the data processing terminal and/or a data memory terminal; and/or (3) according to the identity data of the external power source that is electrically connected to the input terminal. Identification. The control circuit of the power supply device of claim 8, wherein the reference voltage adjustment circuit comprises one of the following circuits: a digital analog conversion circuit, a look-up table circuit, an amplification circuit, or a sample and hold circuit. The control circuit of the power supply device of claim 8, wherein the reference voltage adjustment circuit comprises: an adder, a second feedback signal and a safety difference value related to a voltage of the battery or The correlation signals are added to generate a total signal; and a selection circuit is selected according to the adjustment signal, when the adjustment signal indicates that the power supply capability of the input terminal is relatively strong, selecting a first preset voltage level or The correlation signal is used as the reference voltage; when the adjustment signal indicates that the power supply capability of the input terminal is relatively weak, the output of the adder is selected as the reference voltage. The control circuit of the power supply device of claim 8, wherein the reference voltage adjustment circuit comprises: an adder, a second feedback signal and a safety difference value related to a voltage of the battery or The correlation signals are added to generate a total signal; and a selection circuit is configured to determine a first predetermined voltage level or its associated signal as the reference when the adjustment signal indicates that the power supply capability of the input terminal is relatively strong. Voltage; when the adjustment signal indicates that the power supply capability of the input terminal is relatively weak, at (1) a second preset voltage level or its associated signal, or (2) the output of the adder, above (1) (2) The higher of the two is selected as the reference voltage. The control circuit of the power supply device of claim 8, further comprising: a second operating circuit, generating a second operation signal according to at least the battery voltage or its associated signal and the charging current or its associated signal To control the second switch and control This charging current is made. A power supply control method includes the following steps: (A) converting an input voltage provided by an input terminal to an output voltage to an output terminal, and charging a battery from the output terminal; (B) detecting the a power supply capability at the input; (C) generating an adjustment signal based on the power supply capability of the input; and (D) adjusting the output voltage based on the adjustment signal. The control method of claim 14, wherein the step (A) comprises: (A1) generating a first feedback signal according to the output voltage; and (A2) generating the first feedback signal and a reference voltage In comparison, the level of the output voltage is adjusted to the level corresponding to the reference voltage by feedback control. The control method of claim 15, wherein a first switch is electrically connected between the input end and the output end, a second switch is electrically connected between the output end and the battery, and step (A2) The method further includes: controlling the first switch or the second switch according to a comparison result between the first feedback signal and the reference voltage. The control method of claim 14, wherein the step (D) comprises: adjusting the output voltage in a two-stage, multi-stage or continuous manner according to the adjustment signal. The control method of claim 14, wherein the step (D) comprises: when the adjustment signal indicates that the power supply capability of the input terminal is relatively strong, the output voltage is a first fixed value and the fixed value is Relatively close to the level of the input voltage; when the adjustment signal indicates that the power supply capability of the input terminal is relatively weak, the output voltage is one of the following: (1) the output voltage is a second fixed value and the The fixed value is relatively close to the level of the battery voltage; (2) the output voltage changes with the power supply capability of the input; (3) the output voltage is determined by the sum of the battery voltage and a safety difference; or (4) The output voltage is determined by (a) the sum of the battery voltage and the safety difference Vos, or (b) a predetermined voltage level, and the higher level between the above (a) and (b) To decide.