CN103687148A - Led drive circuit - Google Patents
Led drive circuit Download PDFInfo
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- CN103687148A CN103687148A CN201210345809.9A CN201210345809A CN103687148A CN 103687148 A CN103687148 A CN 103687148A CN 201210345809 A CN201210345809 A CN 201210345809A CN 103687148 A CN103687148 A CN 103687148A
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Abstract
The invention provides an LED drive circuit which, according to a pulse width modulation signal, provides a drive current corresponding to the pulse width modulation signal to an LED source at least containing one LED without distortion. The LED drive circuit has a voltage supply module which has an output end for outputting a supply voltage, a voltage supply control module which receives the pulse width modulation signal and keeps the output current of the voltage supply module stable according to the pulse width modulation signal to make the supply voltage stable, a power amplifier which receives the pulse width modulation signal and the supply voltage and performs power amplification on the supply voltage and outputs a power amplification signal corresponding to a pulse width which is defined by the pulse width modulation signal, and a modulation output module which modulates the power amplification signal and outputs a drive current corresponding to the pulse width.
Description
Technical field
The present invention relates to a kind of LED and drive loop.
Background technology
In the product with LED is manufactured, LED drives loop to be used to the luminous of driving LED always.On market, common a kind of LED drives loop to have voltage supply module, BUF and filtration module now.It exports a supply voltage by voltage supply module, by BUF, is accepted pulse width modulating signal (pwm signal) and supply voltage and supply voltage is cushioned, and makes its power amplification.Voltage after power amplification is the filtering modulation of module after filtering, thereby obtain a drive current, LED is driven, and makes it luminous.
Obviously, the luminosity of LED regulates by pwm signal.
And the variation of pwm signal can affect the stable of supply voltage that voltage supply module exports.
Corresponding relation curve synoptic diagram between Fig. 7 driving voltage that to be the former LED output voltage that drives the voltage supply module in loop export with this LED driving loop, wherein, a represents the profile of the supply voltage of voltage supply module, and b represents that LED drives the profile of the resulting drive current in loop.As shown in Figure 2, when the supply voltage of voltage supply module declines suddenly, the driving voltage that LED drives loop to obtain increases slow especially.
Fig. 8 is that former LED drives the curve synoptic diagram that adds the corresponding pulse duration of pwm signal and gained drive current in loop, and wherein, c is inputted pulse duration and the ideal relationship curve of gained drive current, and obviously, this curve is straight line; D is inputted pulse duration and the actual relationship curve of gained drive current, and obviously, it is a curve.As shown in Figure 3, when the corresponding pulse duration of pwm signal of input is 0.1, the drive current that ideally LED drives loop to obtain is 60mA, but the actual drive current obtaining only has 46.004mA, when pulse duration is 0.5, the drive current that ideally LED drives loop to obtain should be 300.00mA, but the actual drive current obtaining only has 257.14mA,, we wish high-high brightness that the luminosity of LED is LED 50% time, the luminous intrinsic brilliance of LED only has 40% of its high-high brightness.Thereby can find out, while adjusting the brightness of LED by adjusting pwm signal, the actual drive current obtaining more or less be all less than the drive current that ideally should obtain, thereby the light that LED is sent is all on the weak side, has affected comfort level when human eye is watched LED.
This kind of situation is the variation due to pulse width modulating signal, cause that voltage supply module drives the supply spread of voltage of the buffering area (BUF) in loop to LED, thereby make BUF when accepting supply voltage, occur distorted signals, cause this LED to drive the drive current that loop obtains to drive the pwm signal institute corresponding brightness in loop not corresponding with this LED of input, thereby LED cannot reach needed brightness.
The present invention carries out in order to solve above-mentioned problem, object is to provide a kind of LED to drive loop to avoid this distorted signals causing because of the supply spread of voltage that BUF receives, thereby makes LED drive loop to can not get the problem of the drive current corresponding with pwm signal.
Summary of the invention
The inventor, in order to solve above-mentioned problem, has adopted following structure.
The present invention relates to a kind of LED and drive loop, according to pulse width modulating signal, at least containing the LED source of a LED, provide corresponding drive current, it is characterized in that having: voltage supply module, has supply voltage of an output output; Supply voltage control module, thus accept pulse width modulating signal and make the outputting current steadily of voltage supply module allow supply voltage become stable according to pulse width modulating signal; Power amplifier, accepts pulse width modulating signal and carries out power amplification and export a power amplification signal corresponding with pulse width modulating signal with supply voltage and to supply voltage; And modulation output module, a drive current corresponding with pulse width modulating signal is modulated and exported to power amplification signal.
Invention effect and effect
By LED involved in the present invention, drive loop, because supply voltage control module is accepted pulse width modulating signal, and according to pulse width modulating signal, make the outputting current steadily of voltage supply module, thereby allow supply voltage become stable, thereby it is still stable when pulse width modulating signal changes, to supply voltage, and BUF acknowledge(ment) signal also there will not be distortion, thereby LED source can light according to the corresponding brightness of pulse width modulating signal.
Accompanying drawing explanation
Fig. 1 is the structural representation that the present invention LED in an embodiment drives loop;
Fig. 2 is the circuit diagram that the LED of the present invention in embodiment mono-drives loop;
Fig. 3 is that the LED of the present invention in embodiment mono-drives supply voltage in loop and the graph of relation of driving voltage;
Fig. 4 is that the LED of the present invention in embodiment mono-drives the pulse duration in loop and the curve chart of drive current;
Fig. 5 is the circuit diagram that the LED of the present invention in embodiment bis-drives loop;
Fig. 6 is the circuit diagram that the LED of the present invention in embodiment tri-drives loop.
Fig. 7 is that former LED drives the supply voltage in loop and the relation curve schematic diagram of driving voltage;
Fig. 8 is that former LED drives the pulse duration in loop and the curve chart of drive current;
Embodiment
The present invention relates to a kind of LED and drive loop, according to pulse width modulating signal, at least containing the LED source of a LED, provide corresponding drive current.It comprises voltage supply module as a kind of example, has supply voltage of an output output; Supply voltage control module, thus accept pulse width modulating signal and make the outputting current steadily of voltage supply module allow supply voltage become stable according to pulse width modulating signal; Power amplifier, accepts pulse width modulating signal and carries out power amplification and export a power amplification signal corresponding with pulse width modulating signal with supply voltage and to supply voltage; And modulation output module, a drive current corresponding with pulse width modulating signal is modulated and exported to power amplification signal.
As a kind of concrete example, it is a PMOS circuit consisting of not gate, resistance and PMOS that LED involved in the present invention drives the supply voltage control module in loop, the input of not gate is accepted pulse width modulating signal, and output connects the grid of PMOS; The source electrode of PMOS is connected with one end of resistance, and drain electrode is connected with the output of voltage supply module; The other end ground connection of resistance.This LED drives the modulation output module in loop to consist of filter and current mirror circuit, and total resistance of power amplifier and filter equates with the resistance of supplying the resistance in voltage control module.
As the concrete example of another kind, it is a nmos circuit consisting of not gate, resistance and NMOS that LED involved in the present invention drives the supply voltage control module in loop, the input received pulse bandwidth modulation signals of not gate, its output is connected with the grid of NMOS; The source ground of NMOS, drain electrode is connected with one end of resistance; The other end of resistance is connected with the output of voltage supply module.This LED drives the modulation output module in loop to consist of filter and current mirror circuit, and total resistance of power amplifier and filter equates with the resistance of supplying the resistance in voltage control module.
As a kind of concrete example of next, it is BUF that LED involved in the present invention drives the power amplifier in loop, supply voltage control module is a nmos circuit consisting of not gate, resistance and another BUF, the input of not gate is accepted pulse width modulating signal, and output connects the input of another above-mentioned BUF; One end of the output contact resistance of another above-mentioned BUF, an output that connects voltage supply module in two other link, another ground connection; The other end ground connection of resistance.This LED drives the modulation output module in loop to consist of filter and current mirror circuit, and total resistance of power amplifier and filter equates with the resistance of supplying the resistance in voltage control module.
Below in conjunction with the drawings and specific embodiments, the present invention is elaborated.
LED involved in the present invention drives loop, and being used to provides corresponding drive current according to pulse width modulating signal (pwm signal) at least containing the LED source of a LED.
Embodiment mono-
Fig. 1 is the structural representation that the LED in the present embodiment drives loop.As shown in Figure 1, LED drives loop 100 to consist of voltage supply module 110, supply voltage control module 120, power amplifier 130, modulation output module 140.
Supply voltage control module 120 is for accepting pulse width modulating signal 200, thereby thereby according to described pulse width modulating signal, the outputting current steadily of voltage supply module 110 being allowed supplies voltage V
sbecome stable.
Fig. 2 is the circuit diagram that in the present embodiment, LED drives loop.As shown in Figure 2, the function of supply voltage control module 120 is that circuit by consisting of not gate 121, PMOS122 and resistance 123 is realized.The input of not gate 121 is accepted pwm signal, and output connects the grid of PMOS; The source electrode of PMOS122 is connected with one end of resistance 123, and drain electrode is connected with the output of voltage supply module 110; The other end ground connection of resistance 123.
The supply voltage V that power amplifier 130 is exported for accepting pwm signal and voltage supply module
s, and to supply voltage V
scarry out power amplification, thus a power amplification signal corresponding with the pulse duration being determined by pwm signal of output.
In order to realize above function, this power amplifier 130 consists of a buffer, be BUF130(buffer), this BUF130 is provided with that a link is connected with the output of voltage supply module 110, link ground connection, input receive pwm signal 200 and one with the output of modulating output module 140 and being connected.
The output current that 142 pairs of filters 141 of current mirror circuit are exported carries out mirror image, thereby obtains a drive current I corresponding with this output current
out(attribute corresponding with this drive current is driving voltage to the voltage of voltage source 300) comes each LED in driving LED source luminous, and this drive current is steady state value.
At this LED, drive in loop 100 resistance of resistance 123 and BUF130 and filter 141 series connection and total resistance of formation equates.
Below in conjunction with 2 couples of LED of accompanying drawing, drive the operation principle in loop to describe.
When input LED drives the pwm signal in loop 200 to be electronegative potential, the not gate 121 in supply voltage control module 120 is accepted this electronegative potential and is oppositely made it become high potential to this electronegative potential, thereby exports this high potential.Cannot conducting thereby the grid of PMOS122 receives this high potential, no current is by resistance 123, thus in supply voltage control module 120, no current passes through, and the electric current that flows through supply voltage control module 120 is denoted as to I
2, i.e. I
2equal zero.
And the supply voltage of voltage supply module 110 outputs is accepted in BUF130 conducting, thereby have electric current to flow through BUF, this electric current is denoted as I
1, this electric current I
1flow through BUF, BUF is to this electric current I
1thereby corresponding supply voltage carry out one of power amplification output with by pwm signal, determined the corresponding power amplification signal of pulse duration.141 pairs of these power amplification signals of filter in modulation output module 140 carry out modulated filter and export an output current corresponding with pulse duration to current mirror circuit 142, this filter is in the process that power amplification signal is modulated, and electric capacity 145 wherein, electric capacity 46 constantly charge.142 pairs of these output currents of current mirror circuit carry out mirror image, thereby obtain a drive current I
out, this drive current I
outlED in driving LED source is luminous, thereby LED can come luminous according to the corresponding brightness of pwm signal.
When input LED drives the pwm signal 200 in loop 100 to be high potential, BUF130 cannot conducting, thereby cannot accept the supply voltage V that voltage supply module 110 is exported
s.Thereby I
1equal zero, thereby the capacitor discharge of now modulating in the filter in output module 140 maintains the luminous of LED source.
And the not gate 121 of supplying in voltage control module 120 is accepted this high potential and this high potential is carried out oppositely, thus an electronegative potential of output.Thereby the grid of PMOS is accepted this electronegative potential conducting, thereby I
2non-vanishing, I
2through resistance 123.
Because the resistance of resistance 123 equates and supply with total resistance that BUF130 and filter 141 series connection form voltage control module is connected formation circuit parallel connection with BUF130 and filter 141, thereby when being low-voltage, pwm signal flows through the electric current I of BUF
1equal to flow through when pwm signal is high voltage the electric current I of resistance 123
2thereby, having guaranteed no matter at pwm signal, be high voltage or low-voltage, the supply voltage of voltage supply module output is all a steady state value, thereby receives stable supply voltage V during BUF130 conducting
sthereby time there will not be the phenomenon of distorted signals, thereby the luminosity in LED source is corresponding with pwm signal.
Fig. 3 is that LED in the present embodiment drives supply voltage in loop and the corresponding relation figure of driving voltage.As shown in Figure 3, e is the supply voltage curve that voltage supply module is exported, and f is for finally inputing to the driving voltage curve in LED source, obviously, due to the stable output of supply voltage, thereby the shape that LED drives loop 100 resulting driving voltages is also just corresponding to the shape of pwm signal.
Fig. 4 is that the LED in the present embodiment drives the pulse duration in loop and the curve chart of drive current.As shown in Figure 4, g is the pulse duration and the relation curve of drive current that LED in the present embodiment drives loop to obtain, and this curve is very close to straight line, and this g line is intimate parallel and be close to c line.When pulse duration corresponding to pwm signal is 0.5, the drive current that desirable LED drives loop to obtain is 300mA, the drive current that in the present embodiment, LED drives loop to obtain is 313.78, the luminosity of wishing LED source at us is its maximum 50% time, it is 52.3% of its maximum, the very approaching ideally desired luminosity obtaining that the drive current that adopts the LED in the present embodiment to drive loop 100 to obtain makes the luminosity in LED source.Because this curve is very close to straight line, and is close to and equals c line, thereby other on this curve are put resulting brightness and are also just close to and equal ideal value.Compare with d line, efficiently and effectively makes LED source luminous according to the corresponding brightness of pwm signal, and has improved the luminous efficiency in LED source.
The effect of embodiment mono-and effect
In sum, it is steady state value that LED in the present embodiment drives loop 100 to adopt a supply voltage control module 120 consisting of not gate 121, PMOS122 and resistance 123 to realize the supply voltage that voltage supply module inputs to BUF130, thereby the phenomenon that occurs distortion while having avoided BUF130 acknowledge(ment) signal, thereby the relation curve between the pulse duration obtaining and drive current is close to as straight line, thereby the LED in LED source can be luminous according to the corresponding brightness of pulse duration.
Embodiment bis-
It is below the explanation to embodiment bis-.For with embodiment mono-in identical inscape, give identical symbol, and omit identical explanation.
Fig. 5 is the circuit diagram that the LED in the present embodiment drives loop.As shown in Figure 5, LED drives loop 400 to comprise voltage supply module 110, supply voltage control module 220, power amplifier 130, modulation output module 140.This LED drives loop 400 to be used to at least containing the LED source of a LED, provide corresponding drive current I according to pulse width modulating signal (pwm signal)
out.
Supply voltage control module 220 is the nmos circuits that consist of not gate 221, NMOS222 and resistance 223, and the input of not gate 221 receives pwm signal, and its output is connected with the grid of NMOS222; The source ground of NMOS222, drain electrode is connected with one end of resistance 223; The other end of resistance 223 is connected with the output of voltage supply module.
At this LED, drive in loop 400 resistance of resistance 223 and BUF130 and filter 141 series connection and total resistance of formation equates.
Below in conjunction with 5 couples of LED of accompanying drawing, drive the operation principle in loop to describe.
When input LED drives the pwm signal in loop 400 to be electronegative potential, the not gate 221 in supply voltage control module 220 is accepted this electronegative potential and is oppositely made it become high potential to this electronegative potential, thereby exports this high potential.The grid of NMOS222 receives this high potential, and NMOS cannot conducting, so no current is by resistance 223, thereby in supply voltage control module 220, no current passes through, and the electric current that this is flow through to supply voltage control module 220 is denoted as I
2, i.e. this I
2be now zero.
And BUF130 is when the pwm signal receiving is electronegative potential, conducting, thus accept the supply voltage V of voltage supply module 110 outputs
sthereby, there is electric current to flow through BUF130, this electric current is denoted as I
1, this electric current I
1flow through BUF, BUF is to this electric current I
1thereby corresponding supply voltage carry out one of power amplification output with by pwm signal, determined the corresponding power amplification signal of pulse duration.141 pairs of these power amplification signals of filter in modulation output module 140 carry out modulated filter and export an output current corresponding with pulse duration to current mirror circuit 142, this filter is in the process that power amplification signal is modulated, and electric capacity 145 wherein, electric capacity 46 constantly charge.142 pairs of these output currents of current mirror circuit carry out mirror image, thereby obtain a drive current, and the LED in this drive current driving LED source is luminous, thereby LED can come luminous according to the corresponding brightness of pwm signal.
When input LED drives the pwm signal in loop 400 to be high potential, BUF130 cannot conducting, thereby cannot accept the supply voltage that voltage supply module 110 is exported.Thereby no current is from BU F output, i.e. I
1now equal zero, thereby the electric capacity 145 in the filter 141 in modulation output module 140 and electric capacity 146 electric discharges maintain the luminous of LED source.
And the not gate 221 of supplying in voltage control module 220 is accepted this high potential and oppositely made it become electronegative potential to this high potential, thereby export this electronegative potential.The grid of NMOS222 receives this electronegative potential, and because the drain electrode of NMOS is connecting one end of resistance 223, and the other end of this resistance 223 connects the output of voltage supply module, thus NMOS222 conducting,, have electric current I
2by resistance 223, i.e. I
2non-vanishing.
Because the resistance of resistance 223 equates and supply with total resistance that BUF130 and filter 141 series connection form voltage control module is connected formation circuit parallel connection with BUF130 and filter 141, thereby when being low-voltage, pwm signal flows through the electric current I of BUF130
1equal to flow through when pwm signal is high voltage the electric current I of resistance 223
2thereby, guaranteed no matter at pwm signal, be high voltage or low-voltage, the supply voltage V of voltage supply module output
sbe all a steady state value, thereby thereby while receiving stable supply voltage during BUF130 conducting, there will not be the phenomenon of distorted signals, thus the luminosity in LED source is corresponding with pwm signal.
The effect of embodiment bis-and effect
It is steady state value that LED in the present embodiment two drives loop 400 to adopt supply voltage control module 220 consisting of not gate 221, NMOS222 and resistance 223 to realize the supply voltage that voltage supply module inputs to BU F130, thereby the phenomenon that occurs distortion while having avoided BU F130 acknowledge(ment) signal, thereby the relation curve between the pulse duration obtaining and drive current is close to as straight line, LED in LED source can be luminous according to the corresponding brightness of pulse duration, makes this LED drive loop 400 also to have and effect identical in embodiment mono-.
Embodiment tri-
It is below the explanation to embodiment tri-.For with embodiment mono-in identical inscape, give identical symbol, and omit identical explanation.
Fig. 6 is the circuit diagram that the LED in the present embodiment drives loop.As shown in Figure 6, LED drives loop 500 to comprise voltage supply module 110, supply voltage control module 320, power amplifier 130, modulation output module 140.It is to be also used to at least containing the LED source of a LED, provide corresponding drive current according to pulse width modulating signal (pwm signal) that this LED drives loop 500.
Supply voltage control module 320 consists of not gate 321, BUF322 and the resistance 323 identical with BUF130 structure.Wherein, the input of not gate 321 is accepted pwm signal, and its output connects the input of BUF322; One end of the output contact resistance 323 of BUF322, one in two other link of this BUF322 connects voltage supply module 110, another ground connection; The other end ground connection of resistance 323.
At this LED, drive in loop 500 resistance of resistance 323 and BUF130 and filter 141 series connection and total resistance of formation equates.
Obviously, when input LED drives the pwm signal in loop 500 to be electronegative potential, BUF130 conducting, and 321 pairs of these electronegative potentials of not gate in supply voltage control module carry out anti-phase, thereby output high potential, BUF322 cannot conducting, thus in voltage control module, no current passes through.
Due to BUF130 conducting, thus a drive current I of the final output of current mirror circuit
out, LED sends in source the brightness corresponding with pwm signal.
When input LED drives the pwm signal in loop 500 to be high potential, BUF130 cannot conducting, and no current is through BUF130, and the electric capacity 145 in filter 141 and electric capacity 146 electric discharges are luminous thereby LED continues.And not gate 321 in supply voltage control module by high potential an anti-phase and electronegative potential of output, thereby BUF322 conducting has electric current to pass through resistance 323.
Because the resistance of resistance 323 equates and supply with total resistance that BUF130 and filter 141 series connection form voltage control module is connected formation circuit parallel connection with BUF130 and filter 141, thereby the electric current that flows through BUF130 when pwm signal is low-voltage equals to flow through when pwm signal is high voltage the electric current of resistance 223, thereby guaranteed no matter at pwm signal, be high voltage or low-voltage, the supply voltage V of voltage supply module output
sbe all a steady state value, thereby receive stable supply voltage V during BUF130 conducting
sthereby time there will not be the phenomenon of distorted signals, thereby the luminosity in LED source is corresponding with pwm signal.
Embodiment tri-effect and effects
In sum, employing in the present embodiment three supply voltage control module 320 being formed by not gate 321, BUF322 and resistance 323 to have realized the supply voltage that voltage supply module inputs to BUF130 be steady state value, thereby the phenomenon that occurs distortion while having avoided BUF130 acknowledge(ment) signal, thereby the relation curve between the pulse duration obtaining and drive current is close to as straight line, LED in LED source can be luminous according to the corresponding brightness of pulse duration, makes this LED drive loop 500 can access and effect identical in embodiment mono-; In addition, because the BUF322 adopting in this supply voltage control module 320 is identical with the structure of BUF130 as power amplifier, make this LED drive loop 500 designs succinctly, simple in structure.
Claims (7)
1. according to pulse width modulating signal, at least containing the LED source of a LED, provide the LED of corresponding drive current to drive a loop, it is characterized in that having:
Voltage supply module, has supply voltage of an output output;
Supply voltage control module, thus accept pulse width modulating signal and make the outputting current steadily of described voltage supply module allow described supply voltage become stable according to described pulse width modulating signal;
Power amplifier, accepts pulse width modulating signal and carries out power amplification and export a power amplification signal corresponding with the pulse duration being determined by described pulse width modulating signal with described supply voltage and to described supply voltage; And
Modulation output module, modulates and exports a described drive current corresponding with described pulse duration to described power amplification signal.
2. LED according to claim 1 drives loop, it is characterized in that:
Wherein, described supply voltage control module is a PMOS circuit consisting of not gate, PMOS and resistance,
The input of described not gate is accepted described pulse width modulating signal, and its output connects the grid of described PMOS;
The source electrode of described PMOS is connected with one end of described resistance, and its drain electrode is connected with the output of described voltage supply module;
The other end ground connection of described resistance.
3. LED according to claim 2 drives loop, it is characterized in that:
Wherein, described modulation output module consists of filter and current mirror circuit,
Total resistance of described power amplifier and described filter equates with the resistance of described resistance.
4. LED according to claim 1 drives loop, it is characterized in that:
Wherein, described supply voltage control module is a nmos circuit consisting of not gate, NMOS and resistance,
The input of described not gate receives described pulse width modulating signal, and its output is connected with the grid of described NMOS;
The source ground of described NMOS, drain electrode is connected with one end of described resistance;
The other end of described resistance is connected with the output of described voltage supply module.
5. LED according to claim 4 drives loop, it is characterized in that:
Wherein, described modulation output module consists of filter and current mirror circuit,
Total resistance of described power amplifier and described filter equates with the resistance of described resistance.
6. LED according to claim 1 drives loop, it is characterized in that:
Wherein, described power amplifier is BUF
Described supply voltage control module is a circuit consisting of not gate, resistance and another BUF identical with described power amplifier structure,
The input of described not gate is accepted described pulse width modulating signal, and its output connects the input of described another BUF;
The output of described another BUF connects one end of described resistance, and one in two other link connects described voltage supply module, another ground connection;
The other end ground connection of described resistance.
7. LED according to claim 6 drives loop, it is characterized in that:
Wherein, described modulation output module consists of filter and current mirror circuit,
Total resistance of described power amplifier and described filter equates with the resistance of described resistance.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210345809.9A CN103687148A (en) | 2012-09-18 | 2012-09-18 | Led drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210345809.9A CN103687148A (en) | 2012-09-18 | 2012-09-18 | Led drive circuit |
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|---|---|
| CN103687148A true CN103687148A (en) | 2014-03-26 |
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|---|---|---|---|
| CN201210345809.9A Pending CN103687148A (en) | 2012-09-18 | 2012-09-18 | Led drive circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104168692A (en) * | 2014-07-03 | 2014-11-26 | 宁波摩米创新工场电子科技有限公司 | LED large power drive circuit |
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| CN101034875A (en) * | 2006-03-07 | 2007-09-12 | 美国芯源系统股份有限公司 | Class d audio amplifier with PWM and feedback |
| CN101345513A (en) * | 2007-07-11 | 2009-01-14 | 原景科技股份有限公司 | Switching type audio power amplifier capable of suppressing audio noise |
| US20110109294A1 (en) * | 2009-11-10 | 2011-05-12 | Maxim Integrated Products, Inc. | Method for determining pre-bias in a switch-mode controller |
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- 2012-09-18 CN CN201210345809.9A patent/CN103687148A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1653683A (en) * | 2001-03-26 | 2005-08-10 | 哈曼国际工业有限公司 | Pulse Width Modulation Amplifier Enhanced with Digital Signal Processor |
| CN101034875A (en) * | 2006-03-07 | 2007-09-12 | 美国芯源系统股份有限公司 | Class d audio amplifier with PWM and feedback |
| CN101345513A (en) * | 2007-07-11 | 2009-01-14 | 原景科技股份有限公司 | Switching type audio power amplifier capable of suppressing audio noise |
| US20110109294A1 (en) * | 2009-11-10 | 2011-05-12 | Maxim Integrated Products, Inc. | Method for determining pre-bias in a switch-mode controller |
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| CN104168692A (en) * | 2014-07-03 | 2014-11-26 | 宁波摩米创新工场电子科技有限公司 | LED large power drive circuit |
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Owner name: RICOH MICROELECTRONICS CO., LTD. Free format text: FORMER OWNER: RICOH CO. LTD. Effective date: 20150306 |
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Effective date of registration: 20150306 Address after: Japan's Osaka Ikeda City Ji 13 No. 1 room Applicant after: Ricoh Microelectronics Co., Ltd. Address before: Tokyo, Japan, Japan Applicant before: Ricoh Co., Ltd. |
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Effective date of abandoning: 20170822 |