CN201063548Y - Switch power supply and pulsewidth modulation controller thereof - Google Patents
Switch power supply and pulsewidth modulation controller thereof Download PDFInfo
- Publication number
- CN201063548Y CN201063548Y CNU2007201462893U CN200720146289U CN201063548Y CN 201063548 Y CN201063548 Y CN 201063548Y CN U2007201462893 U CNU2007201462893 U CN U2007201462893U CN 200720146289 U CN200720146289 U CN 200720146289U CN 201063548 Y CN201063548 Y CN 201063548Y
- Authority
- CN
- China
- Prior art keywords
- voltage
- under
- input terminal
- output
- positive input
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model provides a novel switch power supply with photocouple short-circuit break-circuit protection and the pulse width modulation PWM controller thereof. The power supply adopts an emitter or a source to drive, the PWM controller judges the failure state of the photocouple by detecting a driving end or a feedback end and makes an compulsory system entrance to reboot the program, realizes the photocouple short-circuit break-circuit protection while no peripheral circuit device and cost are increased, and also further improves the protection to the short-circuit of the system output.
Description
Technical field
The utility model relates to the field of power management of AC-DC, more particularly, relates to and adopts pulse width modulation mode to carry out the AC-DC Switching Power Supply and the Pwm controller thereof of field of power management, especially the small-power emitter or the source drive of power conversion.
Background technology
At present, pulse width modulation (PWM) power supply control technology adopts base stage or gate driving more, and short-circuit protection all is to realize by detecting feedback end voltage or current detecting terminal voltage.When surpassing certain threshold voltage, its voltage also can keep a period of time, control chip is judged system's output short-circuit, system enters start-up mode, set up through system's operation after relatively long start-up time, detect voltage simultaneously, if still there is then process time-delay in system short-circuit fault, system enters startup again.Its protection mechanism too when the optocoupler short interruption.The defective that this protected mode is brought is: the first, and when short-circuit detecting, system keeps maximum power loss between time delay, causes device failure and aircraft bombing easily for small-power power especially.The second, make the control chip complex structure, need to increase extra time-delay and control circuit.
For emitter or source drive power circuit, the power input VCC of control chip share with the output feedback end, output feedback end voltage descends during output short-circuit, by setting under-voltage UVLO threshold voltage, when VCC voltage during less than this under-voltage UVLO threshold voltage, judge output short-circuit, system enters start-up mode.Circuit start is by the system start-up circuit and by emitter or source electrode VCC slowly to be charged, be raised to default starting resistor after, system works.When the optocoupler short circuit or when opening circuit, VCC drops to system restart after the UVLO threshold value, because the ancillary coil in the circuit provides enough energy always, start-up circuit voltage is very high, and VCC moment is raised to starting resistor, and system starts working.Under this state, a large amount of power of system cost and bear big voltage stress can cause device failure or aircraft bombing when serious.
The utility model content
The utility model provides novel PWM controller and uses this kind PWM controller switches power circuit; improved the start-up mode of Switching Power Supply; make system under the condition that does not increase additional devices, realize the protection of optocoupler short interruption, further improved the output short circuit protection of system simultaneously.
According to first aspect of the present utility model, a kind of pulse width modulation (PWM) controller is provided, comprise 4 ports: voltage input end, voltage output end, discharge end and ground end, this PWM controller comprises:
Start module, be connected between voltage input end and the voltage output end;
First under-voltage comparator, positive input terminal is connected to voltage input end, and negative input end is connected to a reference voltage;
Error amplifier, positive input terminal are connected to the positive input terminal of first under-voltage comparator, and negative input end connects described reference voltage;
Band-gap reference circuit provides described reference voltage;
Oscillator produces local oscillating frequency;
The PWM Logic control module is connected to the output of first under-voltage comparator, error amplifier and oscillator;
Drive circuit is connected to the output of PWM Logic control module, and the pwm signal of being exported by the PWM Logic control module drives;
Switching tube is connected to drive circuit;
Second under-voltage comparator, positive input terminal connects the positive input terminal of error amplifier, and negative input end connects described reference voltage;
Charge/discharge control circuit is connected to the output of second under-voltage comparator, is also connected to the startup module;
The logic control pipe is connected to the output of charge/discharge control circuit, is also connected to discharge end.
According to an embodiment of the present utility model, the positive input terminal of first under-voltage comparator of this PWM controller is connected to voltage input end by first resistance; The positive input terminal of error amplifier is connected to the positive input terminal of first under-voltage comparator by second resistance, and the voltage of the positive input terminal of error originated from input amplifier is error voltage; The positive input terminal of second under-voltage comparator is connected to the positive input terminal of error amplifier by the 3rd resistance; The logic control pipe is connected to discharge end by the 4th resistance.
According to an embodiment of the present utility model, the positive input terminal of second under-voltage comparator of this PWM controller is also held by the 4th resistance with being connected to; Switching tube is held by the 5th resistance with being connected to.
According to an embodiment of the present utility model, this PWM controller is when being short-circuited, the voltage of voltage input end drops to the first under-voltage voltage, the upset of first under-voltage comparator, the PWM Logic control module turn-offs system works but does not restart, the pipe of logic control is simultaneously opened, and the discharge end discharge makes voltage atdischarge end zero setting, the 4th resistance control current limliting; When voltage input end voltage continues to drop to the second under-voltage voltage, the upset of second under-voltage comparator, the logic control pipe turn-offs, and starts module simultaneously and is unlocked, and system restarts.
According to second aspect of the present utility model, a kind of Switching Power Supply is provided, one start-up circuit is connected to the limit, source of a transformer, the secondary of transformer has a feedback circuit, the output signal of transformer secondary is fed back to the PWM controller that is positioned at limit, transformer source by an optocoupler, and this PWM controller comprises:
Voltage input end, voltage output end, discharge end and ground end, this PWM controller comprises:
Start module, be connected between voltage input end and the voltage output end;
First under-voltage comparator, positive input terminal is connected to voltage input end, and negative input end is connected to a reference voltage;
Error amplifier, positive input terminal are connected to the positive input terminal of first under-voltage comparator, and negative input end connects described reference voltage;
Band-gap reference circuit provides described reference voltage;
Oscillator produces local oscillating frequency;
The PWM Logic control module is connected to the output of first under-voltage comparator, error amplifier and oscillator;
Drive circuit is connected to the output of PWM Logic control module, and the pwm signal of being exported by the PWM Logic control module drives;
Switching tube is connected to drive circuit;
Second under-voltage comparator, positive input terminal connects the positive input terminal of error amplifier, and negative input end connects described reference voltage;
Charge/discharge control circuit is connected to the output of second under-voltage comparator, is also connected to the startup module;
The logic control pipe is connected to the output of charge/discharge control circuit, is also connected to discharge end.
According to the third aspect of the present utility model, a kind of pulse width modulation (PWM) controller is provided, it is characterized in that, comprise 4 ports: voltage input end, voltage output end, discharge end and ground end, this PWM controller comprises:
Start module, be connected between voltage input end and the voltage output end;
First under-voltage comparator, positive input terminal is connected to voltage input end, and negative input end is connected to a reference voltage;
Error amplifier, positive input terminal are connected to the positive input terminal of first under-voltage comparator, and negative input end connects described reference voltage;
Band-gap reference circuit provides described reference voltage;
Oscillator is connected to the output that starts the module and first under-voltage comparator, produces local oscillating frequency;
Sampling hold circuit is connected to the output that starts module;
The PWM Logic control module is connected to the output of first under-voltage comparator, error amplifier, oscillator and sampling hold circuit;
Drive circuit is connected to the output of PWM Logic control module, and the pwm signal of being exported by the PWM Logic control module drives;
Switching tube is connected to drive circuit;
The 3rd under-voltage comparator, positive input terminal connects the positive input terminal of sampling hold circuit, and negative input end connects described reference voltage;
Charge/discharge control circuit is connected to the output of the 3rd under-voltage comparator, is also connected to the PWM Logic control module;
The logic control pipe is connected to the output of charge/discharge control circuit, is also connected to discharge end.
According to an embodiment of the present utility model, the positive input terminal of first under-voltage comparator in this PWM controller is connected to voltage input end by first resistance; The positive input terminal of error amplifier is connected to the positive input terminal of first under-voltage comparator by second resistance, and the voltage of the positive input terminal of error originated from input amplifier is error voltage; The logic control pipe is connected to discharge end by the 4th resistance.
According to an embodiment of the present utility model, the positive input terminal of the error amplifier in this PWM controller is also held by the 3rd resistance with being connected to; Switching tube is held by the 5th resistance with being connected to.
According to an embodiment of the present utility model, the voltage of each periodic sampling sustaining voltage output of the sampling hold circuit in this PWM controller, and with a threshold voltage relatively, voltage output end voltage will raise when short circuit, when voltage output end voltage is higher than described threshold voltage, the upset of the 3rd under-voltage comparator, charge/discharge control circuit turn-offs the PWM Logic control module and quits work, open the logic control pipe simultaneously, the discharge end discharge; When voltage input end voltage was reduced to under-voltage voltage, the upset of first under-voltage comparator restarted.
According to fourth aspect of the present utility model, a kind of Switching Power Supply is provided, one start-up circuit is connected to the limit, source of a transformer, the secondary of transformer has a feedback circuit, the output signal of transformer secondary is fed back to the PWM controller that is positioned at limit, transformer source by an optocoupler, and this PWM controller comprises:
Start module, be connected between voltage input end and the voltage output end;
First under-voltage comparator, positive input terminal is connected to voltage input end, and negative input end is connected to a reference voltage;
Error amplifier, positive input terminal are connected to the positive input terminal of first under-voltage comparator, and negative input end connects described reference voltage;
Band-gap reference circuit provides described reference voltage;
Oscillator is connected to the output that starts the module and first under-voltage comparator, produces local oscillating frequency;
Sampling hold circuit is connected to the output that starts module;
The PWM Logic control module is connected to the output of first under-voltage comparator, error amplifier, oscillator and sampling hold circuit;
Drive circuit is connected to the output of PWM Logic control module, and the pwm signal of being exported by the PWM Logic control module drives;
Switching tube is connected to drive circuit;
The 3rd under-voltage comparator, positive input terminal connects the positive input terminal of sampling hold circuit, and negative input end connects described reference voltage;
Charge/discharge control circuit is connected to the output of the 3rd under-voltage comparator, is also connected to the PWM Logic control module;
The logic control pipe is connected to the output of charge/discharge control circuit, is also connected to discharge end.
Two kinds of PWM controllers that the utility model provides and the Switching Power Supply of using these two kinds of PWM controllers have respectively been improved the start-up mode of Switching Power Supply; make system under the condition that does not increase additional devices; realize the protection of optocoupler short interruption, further improved the output short circuit protection of system simultaneously.
Wherein, at a kind of PWM controller and adopt in the implementation of switching circuit of this kind PWM controller; detecting voltage input end voltage drops to behind the first under-voltage threshold voltage system and turn-offs and quit work but do not restart; system entered start-up mode after voltage input end voltage continued to drop to the second under-voltage threshold voltage; drop to the second under-voltage threshold voltage period P WM control chip at voltage input end voltage by the first under-voltage threshold voltage system is comprised that start-up circuit is arranged to initial condition; carry out complete start-up course to guarantee next periodic system; thereby reduce short-circuit dissipation and current/voltage, reach the purpose of protection.
At a kind of PWM controller and adopt in the implementation of switching circuit of this kind PWM controller, PWM monitoring control devices switching tube emitter or source voltage terminal, when detecting it greater than a threshold voltage, system quits work and with the start-up circuit initialization, when voltage input end voltage was reduced to under-voltage threshold voltage, system restarted.
Description of drawings
The above and other feature of the utility model, character and advantage will be by becoming more obvious below in conjunction with accompanying drawing to the description of embodiment, and in the accompanying drawings, identical Reference numeral is represented identical feature all the time, wherein:
Fig. 1 shows the structure chart according to the PWM controller of an embodiment of the present utility model;
Fig. 2 shows the structure chart according to the PWM controller of another embodiment of the present utility model;
Fig. 3 shows the emitter with the protection of optocoupler short interruption and drives inverse-excitation type AD-DC Switching Power Supply structure chart;
Fig. 4 shows the oscillogram according to important voltage node in the switching power circuit of the present utility model.
Embodiment
At first with reference to shown in Figure 1, Fig. 1 shows the structure chart according to the PWM controller of an embodiment of the present utility model.It is a kind of pulse width modulation (PWM) controller, it is characterized in that, comprises 4 ports: voltage input end VCC, voltage output end VOUT, discharge end VA and ground end GND, and this PWM controller comprises:
First under-voltage comparator (UVLO) 202, positive input terminal is connected to voltage input end VCC, and negative input end is connected to a reference voltage Vref; According to embodiment shown in Figure 1, the positive input terminal of first under-voltage comparator 202 is connected to voltage input end VCC by first resistance 212;
Band-gap reference circuit (Band Gap) 205 provides reference voltage Vref; With reference to embodiment shown in Figure 1, above-mentioned reference voltage Vref is provided for the negative input end of first under-voltage comparator 202, error amplifier 204 and second under-voltage comparator 209;
PWM Logic control module 206 is connected to the output of first under-voltage comparator 202, error amplifier 204 and oscillator 203;
Second under-voltage comparator (UVLO) 209, positive input terminal connects the positive input terminal of error amplifier 204, and negative input end connects reference voltage Vref; With reference to embodiment shown in Figure 1, the positive input terminal of second under-voltage comparator 209 is connected to the positive input terminal of error amplifier 204 by the 3rd resistance 214;
Charge/discharge control circuit 210 is connected to the output of second under-voltage comparator 209, is also connected to start module 201;
Continue with reference to embodiment shown in Figure 1, the positive input terminal of second under-voltage comparator 209 is also held GND by the 4th resistance 215 with being connected to; And switching tube 208 is also held GND by the 5th resistance 217 with being connected to.
According to an embodiment, this switching tube 208 and logic control pipe 211 all adopt MOS to close and realize.
The operation principle of said PWM controller is as follows:
When being short-circuited, such as because optocoupler when being short-circuited, the voltage of voltage input end VCC drops to the first under-voltage voltage, 202 upsets of first under-voltage comparator, PWM Logic control module 206 turn-offs system works but does not restart, the pipe of logic control simultaneously 211 is opened, and discharge end VA discharge makes the zero setting of discharge end VA voltage, the 4th resistance 216 control current limlitings;
When voltage input end VCC voltage continues to drop to the second under-voltage voltage, 209 upsets of second under-voltage comparator, logic control pipe 211 turn-offs, and starts module 201 simultaneously and is unlocked, and system restarts.
Adopt above-mentioned PWM controller shown in Figure 1, the utility model also provides a kind of Switching Power Supply, one start-up circuit is connected to the limit, source of a transformer, the secondary of transformer has a feedback circuit, and the output signal of transformer secondary is fed back to the PWM controller that is positioned at limit, transformer source by an optocoupler.
With reference to shown in Figure 3, Fig. 3 shows the emitter with the protection of optocoupler short interruption and drives inverse-excitation type AD-DC Switching Power Supply structure chart.
Wherein, start-up circuit is positioned at the limit, source of transformer 102, and start-up circuit comprises resistance 103, resistance 106, electric capacity 111 and power switch pipe 124.Start-up circuit is by one group of supplementary aid, and comprising: resistance 104, resistance 105, diode 118, diode 122, electric capacity 114 are connected to the limit, source of transformer 102.
The secondary of transformer 102 has a feedback circuit, and feedback circuit comprises resistance 108, resistance 109, electric capacity 117, voltage reference circuit 121 and optocoupler 101.Also by one group of supplementary aid, comprising: resistance 107, electric capacity 115, electric capacity 116, diode 120, inductance 123 are connected to the secondary of transformer 102 to feedback circuit.Wherein, this optocoupler 101 comprises four outside ports: first port one 1 is connected to the discharge output VA of PWM controller; Second port one 2 is connected to the voltage input end VCC of PWM controller; The 3rd port one 3 is connected to the secondary of transformer 102 by resistance 107 and diode 120; The 4th port one 4 is connected to feedback circuit.
Wherein, the structure of this PWM controller 100 can comprise 4 outside ports as shown in Figure 1: voltage input end VCC, voltage output end VOUT, discharge end VA and ground end GND, and the internal structure of this PWM controller comprises:
First under-voltage comparator (UVLO) 202, positive input terminal is connected to voltage input end VCC, and negative input end is connected to a reference voltage Vref; The positive input terminal of first under-voltage comparator 202 is connected to voltage input end VCC by first resistance 212;
Band-gap reference circuit 205 provides reference voltage Vref; Above-mentioned reference voltage Vref is provided for the negative input end of first under-voltage comparator 202, error amplifier 204 and second under-voltage comparator 209;
PWM Logic control module 206 is connected to the output of first under-voltage comparator 202, error amplifier 204 and oscillator 203;
Second under-voltage comparator (UVLO) 209, positive input terminal connects the positive input terminal of error amplifier 204, and negative input end connects reference voltage Vref; The positive input terminal of second under-voltage comparator 209 is connected to the positive input terminal of error amplifier 204 by the 3rd resistance 214;
Charge/discharge control circuit 210 is connected to the output of second under-voltage comparator 209, is also connected to start module 201;
The positive input terminal of this second under-voltage comparator 209 is also held GND by the 4th resistance 215 with being connected to; And switching tube 208 is also held GND by the 5th resistance 217 with being connected to.
According to an embodiment, this switching tube 208 and logic control pipe 211 all adopt MOS to close and realize.
Switching power circuit as shown in Figure 3, critical piece wherein comprises: PWM controller 100, optocoupler 101, transformer 102, power switch pipe 124.By resistance 108,109, electric capacity 117, the feedback circuit that voltage reference circuit 121 and optocoupler 101 formed feeds back to the power input VCC of the PWM controller 100 on limit, transformer 102 source with transformer 102 secondary output signals, thereby the conducting duty ratio that PWM controller 100 is regulated power switch pipe 124 according to the height of power input VCC voltage reaches the purpose of adjusting output.Voltage input end VCC provides power supply for PWM controller 100 simultaneously.Start-up circuit is by resistance 103,106, and electric capacity 111 and power switch pipe 124 are formed.Power supply powers up or system when restarting, and input voltage slowly charges through 103 pairs of electric capacity 111 of resistance, and the power output end OUT of PWM controller 100 follows the lifting of discharge output VA voltage by switching tube 124.Pass through the startup module 201 of inner PWM controller 100 inside again, power input VCC also follows power output end OUT voltage and rises, PWM controller 100 starts after reaching the power output end VCC threshold voltage Vs of setting, start-up circuit insulating power supply output OUT and power input VCC, system's operate as normal are turn-offed in pulse output simultaneously.
When switching power circuit is worked, after optocoupler 101 breaks down two states is arranged.A kind of is first port one 1 and second section mouth 12 short circuit of optocoupler 101; discharge output VA voltage is dragged down by power input VCC is clamped; thereby off switch pipe 124; owing to there is not pulse; transformer 102 secondary do not have energy supply power input VCC; cause power input VCC voltage to descend; when reducing to threshold value; promptly during the first under-voltage voltage U VLO, first under-voltage comparator, 202 counter-rotatings in the PWM controller 100, output signal is turn-offed the PWM internal circuit; system enters restarting mode; because VA is clamped by power input VCC for the discharge output, system can't restart, and forms protection.
When other short interruption takes place optocoupler 101, system power supply input VCC will can not get energy and cause voltage to descend, and discharge end VA raises owing to ancillary coil continues to provide electric current simultaneously.Switching Power Supply shown in Figure 3 is utilized the design of PWM controller, detects the fault of optocoupler, and the control system action is protected.
With reference to figure 2, Fig. 2 shows the structure chart according to the PWM controller of another embodiment of the present utility model.It also is a kind of pulse width modulation (PWM) controller, comprises 4 ports: voltage input end VCC, voltage output end VOUT, discharge end VA and ground end GND, and this PWM controller comprises:
First under-voltage comparator 202, positive input terminal is connected to voltage input end VCC, and negative input end is connected to a reference voltage Vref; With reference to embodiment shown in Figure 2, the positive input terminal of first under-voltage comparator 202 is connected to voltage input end VCC by first resistance 212;
Band-gap reference circuit 205 provides described reference voltage Vref;
Sampling hold circuit 220 is connected to the output that starts module 201;
PWM Logic control module 206 is connected to the output of first under-voltage comparator 202, error amplifier 204, oscillator 203 and sampling hold circuit 220;
The 3rd under-voltage comparator 221, positive input terminal connects the positive input terminal of sampling hold circuit 220, and negative input end connects described reference voltage Vref;
Charge/discharge control circuit 210 is connected to the output of the 3rd under-voltage comparator 221, is also connected to PWM Logic control module 206;
Continuation is with reference to figure 2, and the positive input terminal of error amplifier 204 is also held GND by the 3rd resistance 214 with being connected to; Switching tube 208 is held GND by the 5th resistance 217 with being connected to.
The operation principle of said PWM controller is as follows:
The voltage of sampling hold circuit 220 each periodic sampling sustaining voltage output OUT, and with a threshold voltage relatively, voltage output end OUT voltage will raise when short circuit, when voltage output end OUT voltage is higher than described threshold voltage, 221 upsets of the 3rd under-voltage comparator, charge/discharge control circuit 210 turn-offs PWM Logic control module 206 and quits work, and opens logic control pipe 211 simultaneously, discharge end VA discharge; When voltage input end VCC voltage was reduced to under-voltage voltage, 202 upsets of first under-voltage comparator restarted.
Adopt above-mentioned PWM controller shown in Figure 2, the utility model also provides a kind of Switching Power Supply, one start-up circuit is connected to the limit, source of a transformer, the secondary of transformer has a feedback circuit, and the output signal of transformer secondary is fed back to the PWM controller that is positioned at limit, transformer source by an optocoupler.
With reference to shown in Figure 3, Fig. 3 shows the emitter with the protection of optocoupler short interruption and drives inverse-excitation type AD-DC Switching Power Supply structure chart.
Wherein, start-up circuit is positioned at the limit, source of transformer 102, and start-up circuit comprises resistance 103, resistance 106, electric capacity 111 and power switch pipe 124.Start-up circuit is by one group of supplementary aid, and comprising: resistance 104, resistance 105, diode 118, diode 122, electric capacity 114 are connected to the limit, source of transformer 102.
The secondary of transformer 102 has a feedback circuit, and feedback circuit comprises resistance 108, resistance 109, electric capacity 117, voltage reference circuit 121 and optocoupler 101.Also by one group of supplementary aid, comprising: resistance 107, electric capacity 115, electric capacity 116, diode 120, inductance 123 are connected to the secondary of transformer 102 to feedback circuit.Wherein, this optocoupler 101 comprises four outside ports: first port one 1 is connected to the discharge output VA of PWM controller; Second port one 2 is connected to the voltage input end VCC of PWM controller; The 3rd port one 3 is connected to the secondary of transformer 102 by resistance 107 and diode 120; The 4th port one 4 is connected to feedback circuit.
Wherein, the structure of this PWM controller 100 can comprise 4 outside ports as shown in Figure 1: voltage input end VCC, voltage output end VOUT, discharge end VA and ground end GND, and the internal structure of this PWM controller comprises:
First under-voltage comparator 202, positive input terminal is connected to voltage input end VCC, and negative input end is connected to a reference voltage Vref; With reference to embodiment shown in Figure 2, the positive input terminal of first under-voltage comparator 202 is connected to voltage input end VCC by first resistance 212;
Band-gap reference circuit 205 provides described reference voltage Vref;
Sampling hold circuit 220 is connected to the output that starts module 201;
PWM Logic control module 206 is connected to the output of first under-voltage comparator 202, error amplifier 204, oscillator 203 and sampling hold circuit 220;
The 3rd under-voltage comparator 221, positive input terminal connects the positive input terminal of sampling hold circuit 220, and negative input end connects described reference voltage Vref;
Charge/discharge control circuit 210 is connected to the output of the 3rd under-voltage comparator 221, is also connected to PWM Logic control module 206;
Two kinds of implementations that the utility model provides have been introduced new structure and have been detected and judge optocoupler short circuit or short circuit; and in time cut off system works; make the system start-up circuit revert to initial condition; the discharge output VA zero setting of PWM controller; make the next one restart relatively long initial power-up start-up course of time of process experience; thereby reduced the loss of electric current and voltage, on the basis that does not increase system cost substantially, realized the protection of optocoupler short interruption device impact and power.
The switching circuit that the utility model provides the PWM controller and adopts this kind PWM controller, PWM monitoring control devices switching tube emitter or source voltage terminal, when detecting it greater than a threshold voltage, system quits work and with the start-up circuit initialization, when voltage input end voltage was reduced to under-voltage threshold voltage, system restarted.
The foregoing description provides to being familiar with the person in the art and realizes or use of the present utility model; those skilled in the art can be under the situation that does not break away from invention thought of the present utility model; the foregoing description is made various modifications or variation; thereby protection range of the present utility model do not limit by the foregoing description, and should be the maximum magnitude that meets the inventive features that claims mention.
Claims (10)
1. a pulse width modulation (PWM) controller is characterized in that, comprises 4 ports: voltage input end (VCC), voltage output end (VOUT), discharge end (VA) and ground end (GND), and this PWM controller comprises:
Start module (201), be connected between voltage input end (VCC) and the voltage output end (VOUT);
First under-voltage comparator (202), positive input terminal are connected to voltage input end (VCC), and negative input end is connected to a reference voltage (Vref);
Error amplifier (204), positive input terminal is connected to the positive input terminal of first under-voltage comparator (202), and negative input end connects described reference voltage (Vref);
Band-gap reference circuit (205) provides described reference voltage (Vref);
Oscillator (203) produces local oscillating frequency;
PWM Logic control module (206) is connected to the output of first under-voltage comparator (202), error amplifier (204) and oscillator (203);
Drive circuit (207) is connected to the output of PWM Logic control module (206), and the pwm signal of being exported by PWM Logic control module (206) drives;
Switching tube (208) is connected to drive circuit (207);
Second under-voltage comparator (209), positive input terminal connects the positive input terminal of error amplifier (204), and negative input end connects described reference voltage (Vref);
Charge/discharge control circuit (210) is connected to the output of second under-voltage comparator (209), is also connected to start module (201);
Logic control pipe (211) is connected to the output of charge/discharge control circuit (210), is also connected to discharge end (VA).
2. PWM controller as claimed in claim 1 is characterized in that,
The positive input terminal of first under-voltage comparator (202) is connected to voltage input end (VCC) by first resistance (212);
The positive input terminal of error amplifier (204) is connected to the positive input terminal of first under-voltage comparator (202) by second resistance (213), and the voltage of the positive input terminal of error originated from input amplifier (204) is error voltage (VCC_Err);
The positive input terminal of second under-voltage comparator (209) is connected to the positive input terminal of error amplifier (204) by the 3rd resistance (214);
Logic control pipe (211) is connected to discharge end (VA) by the 4th resistance (216).
3. PWM controller as claimed in claim 2 is characterized in that,
The positive input terminal of described second under-voltage comparator (209) is also held (GND) by the 4th resistance (215) with being connected to;
Switching tube (208) is held (GND) by the 5th resistance (217) with being connected to.
4. PWM controller as claimed in claim 3 is characterized in that,
When being short-circuited, the voltage of voltage input end (VCC) drops to the first under-voltage voltage, first under-voltage comparator (202) upset, PWM Logic control module (206) turn-offs system works but does not restart, logic control pipe (211) is opened simultaneously, discharge end (VA) discharge makes the zero setting of discharge end (VA) voltage, the 4th resistance (216) control current limliting;
When voltage input end (VCC) voltage continues to drop to the second under-voltage voltage, second under-voltage comparator (209) upset, logic control pipe (211) turn-offs, and starts module (201) simultaneously and is unlocked, and system restarts.
5. Switching Power Supply, one start-up circuit is connected to the limit, source of a transformer, and the secondary of transformer has a feedback circuit, and the output signal of transformer secondary is fed back to the PWM controller that is positioned at limit, transformer source by an optocoupler, it is characterized in that this PWM controller comprises:
Voltage input end (VCC), voltage output end (VOUT), discharge end (VA) and ground end (GND), this PWM controller comprises:
Start module (201), be connected between voltage input end (VCC) and the voltage output end (VOUT);
First under-voltage comparator (202), positive input terminal are connected to voltage input end (VCC), and negative input end is connected to a reference voltage (Vref);
Error amplifier (204), positive input terminal is connected to the positive input terminal of first under-voltage comparator (202), and negative input end connects described reference voltage (Vref);
Band-gap reference circuit (205) provides described reference voltage (Vref);
Oscillator (203) produces local oscillating frequency;
PWM Logic control module (206) is connected to the output of first under-voltage comparator (202), error amplifier (204) and oscillator (203);
Drive circuit (207) is connected to the output of PWM Logic control module (206), and the pwm signal of being exported by PWM Logic control module (206) drives;
Switching tube (208) is connected to drive circuit (207);
Second under-voltage comparator (209), positive input terminal connects the positive input terminal of error amplifier (204), and negative input end connects described reference voltage (Vref);
Charge/discharge control circuit (210) is connected to the output of second under-voltage comparator (209), is also connected to start module (201);
Logic control pipe (211) is connected to the output of charge/discharge control circuit (210), is also connected to discharge end (VA).
6. a pulse width modulation (PWM) controller is characterized in that, comprises 4 ports: voltage input end (VCC), voltage output end (VOUT), discharge end (VA) and ground end (GND), and this PWM controller comprises:
Start module (201), be connected between voltage input end (VCC) and the voltage output end (VOUT);
First under-voltage comparator (202), positive input terminal are connected to voltage input end (VCC), and negative input end is connected to a reference voltage (Vref);
Error amplifier (204), positive input terminal is connected to the positive input terminal of first under-voltage comparator (202), and negative input end connects described reference voltage (Vref);
Band-gap reference circuit (205) provides described reference voltage (Vref);
Oscillator (203) is connected to the output that starts module (201) and first under-voltage comparator (202), produces local oscillating frequency;
Sampling hold circuit (220) is connected to the output that starts module (201);
PWM Logic control module (206) is connected to the output of first under-voltage comparator (202), error amplifier (204), oscillator (203) and sampling hold circuit (220);
Drive circuit (207) is connected to the output of PWM Logic control module (206), and the pwm signal of being exported by PWM Logic control module (206) drives;
Switching tube (208) is connected to drive circuit (207);
The 3rd under-voltage comparator (221), positive input terminal connects the positive input terminal of sampling hold circuit (220), and negative input end connects described reference voltage (Vref);
Charge/discharge control circuit (210) is connected to the output of the 3rd under-voltage comparator (221), is also connected to PWM Logic control module (206);
Logic control pipe (211) is connected to the output of charge/discharge control circuit (210), is also connected to discharge end (VA).
7. PWM controller as claimed in claim 6 is characterized in that,
The positive input terminal of first under-voltage comparator (202) is connected to voltage input end (VCC) by first resistance (212);
The positive input terminal of error amplifier (204) is connected to the positive input terminal of first under-voltage comparator (202) by second resistance (213), and the voltage of the positive input terminal of error originated from input amplifier (204) is error voltage (VCC_Err);
Logic control pipe (211) is connected to discharge end (VA) by the 4th resistance (216).
8. PWM controller as claimed in claim 7 is characterized in that,
The positive input terminal of described error amplifier (204) is also held (GND) by the 3rd resistance (214) with being connected to;
Switching tube (208) is held (GND) by the 5th resistance (217) with being connected to.
9. PWM controller as claimed in claim 8 is characterized in that,
The voltage of each periodic sampling sustaining voltage output (OUT) of sampling hold circuit (220), and with a threshold voltage relatively, voltage output end when short circuit (OUT) voltage will raise, when voltage output end (OUT) when voltage is higher than described threshold voltage, the 3rd under-voltage comparator (221) upset, charge/discharge control circuit (210) turn-offs PWM Logic control module (206) and quits work, and opens logic control pipe (211) simultaneously, discharge end (VA) discharge;
When voltage input end (VCC) when voltage is reduced to under-voltage voltage, first under-voltage comparator (202) upset restarts.
10. Switching Power Supply, one start-up circuit is connected to the limit, source of a transformer, and the secondary of transformer has a feedback circuit, and the output signal of transformer secondary is fed back to the PWM controller that is positioned at limit, transformer source by an optocoupler, it is characterized in that this PWM controller comprises:
Start module (201), be connected between voltage input end (VCC) and the voltage output end (VOUT);
First under-voltage comparator (202), positive input terminal are connected to voltage input end (VCC), and negative input end is connected to a reference voltage (Vref);
Error amplifier (204), positive input terminal is connected to the positive input terminal of first under-voltage comparator (202), and negative input end connects described reference voltage (Vref);
Band-gap reference circuit (205) provides described reference voltage (Vref);
Oscillator (203) is connected to the output that starts module (201) and first under-voltage comparator (202), produces local oscillating frequency;
Sampling hold circuit (220) is connected to the output that starts module (201);
PWM Logic control module (206), be connected to first under-voltage comparator (202),
The output of error amplifier (204), oscillator (203) and sampling hold circuit (220);
Drive circuit (207) is connected to the output of PWM Logic control module (206), and the pwm signal of being exported by PWM Logic control module (206) drives;
Switching tube (208) is connected to drive circuit (207);
The 3rd under-voltage comparator (221), positive input terminal connects the positive input terminal of sampling hold circuit (220), and negative input end connects described reference voltage (Vref);
Charge/discharge control circuit (210) is connected to the output of the 3rd under-voltage comparator (221), is also connected to PWM Logic control module (206);
Logic control pipe (211) is connected to the output of charge/discharge control circuit (210), is also connected to discharge end (VA).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201462893U CN201063548Y (en) | 2007-08-07 | 2007-08-07 | Switch power supply and pulsewidth modulation controller thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201462893U CN201063548Y (en) | 2007-08-07 | 2007-08-07 | Switch power supply and pulsewidth modulation controller thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201063548Y true CN201063548Y (en) | 2008-05-21 |
Family
ID=39451934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2007201462893U Expired - Lifetime CN201063548Y (en) | 2007-08-07 | 2007-08-07 | Switch power supply and pulsewidth modulation controller thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201063548Y (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102035182A (en) * | 2010-11-26 | 2011-04-27 | 中国科学院上海技术物理研究所 | Universal type short circuit isolation protection circuit for flyback switching power supply |
| CN102263515A (en) * | 2011-03-31 | 2011-11-30 | 深圳市富满电子有限公司南山分公司 | AC-DC (alternating current-direct current) power conversion chip and power conversion circuit |
| CN101630173B (en) * | 2009-08-20 | 2012-06-20 | 四川和芯微电子股份有限公司 | CMOS band-gap reference source circuit with low flash noise |
| CN102736718A (en) * | 2011-04-11 | 2012-10-17 | 深圳市凯丰达科技有限公司 | Pulse width modulation switching power supply |
| CN102843050A (en) * | 2012-07-12 | 2012-12-26 | 上海新进半导体制造有限公司 | Method and circuit for improving system output characteristics of switch power supply |
| CN103414322A (en) * | 2013-08-27 | 2013-11-27 | 成都芯源系统有限公司 | Control circuit, switch converter and control method thereof |
| CN101959339B (en) * | 2009-07-17 | 2014-03-05 | 上海沙丘微电子有限公司 | High-voltage LED driving chip dual-power supply circuit |
| CN105186859A (en) * | 2014-09-17 | 2015-12-23 | 成都芯源系统有限公司 | Switching converter and method for discharging output terminal thereof |
| CN106612065A (en) * | 2015-10-17 | 2017-05-03 | 英特希尔美国公司 | Enhanced fault reporting in voltage regulators |
| CN116819166A (en) * | 2023-08-31 | 2023-09-29 | 苏州贝克微电子股份有限公司 | High-voltage end undervoltage detection circuit |
-
2007
- 2007-08-07 CN CNU2007201462893U patent/CN201063548Y/en not_active Expired - Lifetime
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101959339B (en) * | 2009-07-17 | 2014-03-05 | 上海沙丘微电子有限公司 | High-voltage LED driving chip dual-power supply circuit |
| CN101630173B (en) * | 2009-08-20 | 2012-06-20 | 四川和芯微电子股份有限公司 | CMOS band-gap reference source circuit with low flash noise |
| CN102035182A (en) * | 2010-11-26 | 2011-04-27 | 中国科学院上海技术物理研究所 | Universal type short circuit isolation protection circuit for flyback switching power supply |
| CN102263515A (en) * | 2011-03-31 | 2011-11-30 | 深圳市富满电子有限公司南山分公司 | AC-DC (alternating current-direct current) power conversion chip and power conversion circuit |
| CN102736718A (en) * | 2011-04-11 | 2012-10-17 | 深圳市凯丰达科技有限公司 | Pulse width modulation switching power supply |
| CN102843050A (en) * | 2012-07-12 | 2012-12-26 | 上海新进半导体制造有限公司 | Method and circuit for improving system output characteristics of switch power supply |
| CN102843050B (en) * | 2012-07-12 | 2015-07-22 | 上海新进半导体制造有限公司 | Method and circuit for improving system output characteristics of switch power supply |
| CN103414322A (en) * | 2013-08-27 | 2013-11-27 | 成都芯源系统有限公司 | Control circuit, switch converter and control method thereof |
| CN103414322B (en) * | 2013-08-27 | 2015-11-25 | 成都芯源系统有限公司 | Control circuit, switch converter and control method thereof |
| CN105186859A (en) * | 2014-09-17 | 2015-12-23 | 成都芯源系统有限公司 | Switching converter and method for discharging output terminal thereof |
| CN105186859B (en) * | 2014-09-17 | 2018-06-19 | 成都芯源系统有限公司 | Switching converter and method for discharging output terminal thereof |
| CN106612065A (en) * | 2015-10-17 | 2017-05-03 | 英特希尔美国公司 | Enhanced fault reporting in voltage regulators |
| CN106612065B (en) * | 2015-10-17 | 2020-06-12 | 英特希尔美国公司 | Enhanced fault reporting in a voltage regulator |
| CN116819166A (en) * | 2023-08-31 | 2023-09-29 | 苏州贝克微电子股份有限公司 | High-voltage end undervoltage detection circuit |
| CN116819166B (en) * | 2023-08-31 | 2023-11-03 | 苏州贝克微电子股份有限公司 | High-voltage end undervoltage detection circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201063548Y (en) | Switch power supply and pulsewidth modulation controller thereof | |
| CN102263544B (en) | IGBT driving circuit with electrification protection | |
| CN101989810B (en) | Method and apparatus for implementing a power converter input terminal voltage discharge circuit | |
| CN108964426B (en) | Control chip of synchronous rectifier tube and AC-DC system | |
| CN103227559A (en) | Method of forming a switched mode power supply controller device with an off mode and structure therefor | |
| CN101674026B (en) | Low standby loss control circuit of switching power supply capable of automatically detecting load | |
| CN110406381B (en) | Power battery precharge switching device based on IGBT module | |
| CN102685971B (en) | Conversion controller | |
| CN101976959B (en) | Controller and adjustment and control method for controller | |
| CN102523654A (en) | Drive circuit of LED light source, control circuit thereof and control method thereof | |
| CN105576955A (en) | High voltage starting circuit and high voltage starting method | |
| CN203722218U (en) | Electrostatic protection device, intelligent power module and variable frequency household appliance | |
| CN101944856B (en) | Control circuit of switching power supply for primary side control | |
| CN112103920A (en) | DC/DC converter overcurrent protection circuit | |
| CN102157919A (en) | Boost power supply conversion device | |
| CN202424502U (en) | Switching power supply circuit | |
| CN110829383A (en) | Multi-mode protection circuit of double-winding secondary feedback switching power supply | |
| CN214900648U (en) | Power management chip and switching power supply management system | |
| CN214100893U (en) | Solar lawn lamp control circuit with low standby power consumption | |
| CN117458833B (en) | Battery-powered frequency converter low-power-consumption startup awakening circuit and frequency converter | |
| CN101399500A (en) | Resonance semi-bridge power source controller | |
| CN113098103A (en) | Power-down discharge circuit and method and power management system | |
| CN116565808A (en) | Primary side feedback FB pin short-circuit protection circuit and method | |
| CN207475402U (en) | Integrated super-pressure start-up circuit and Switching Power Supply in the controller | |
| CN113206536B (en) | Charging circuit capable of realizing short-circuit protection and automatic restart |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20080521 |
|
| CX01 | Expiry of patent term |