CN107592013A - Control circuit and method applied to bootstrap capacitor power loss recovery in DC DC converters - Google Patents
Control circuit and method applied to bootstrap capacitor power loss recovery in DC DC converters Download PDFInfo
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- CN107592013A CN107592013A CN201710868710.XA CN201710868710A CN107592013A CN 107592013 A CN107592013 A CN 107592013A CN 201710868710 A CN201710868710 A CN 201710868710A CN 107592013 A CN107592013 A CN 107592013A
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- bootstrap capacitor
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Abstract
The invention discloses the control circuit and method applied to boottrap capacitor power loss recovery in DC DC converters,Including the first main switch,Second main switch,Inductance,Bootstrap capacitor,Second diode,First switch tube drive circuit,Second switch tube drive circuit,D type flip flop and level shifting circuit,This control circuit can solve in DC DC converters bootstrap capacitor and cause showing for system output abnormality or system stalls because small loaded/unloaded causes boottrap capacitor power down,And after the node BS and switching node SW of bootstrap capacitor and the second diode short circuit revocations,Boottrap capacitor recovers to charge automatically,So as to ensure the normal operation of system,And the present invention need not export dummy load,Load under-voltage detection,Timing circuit,Or increase additional flip-flop,So as to simplify circuit design difficulty,Strengthening system stability,Simultaneously,The present invention realizes boottrap capacitor voltage lifting for Cycle by Cycle,Realize that the fast quick-recovery of system is stable.
Description
Technical field
The present invention relates to the DC-DC converter with bootstrap capacitor, more particularly to applied to electricity of being booted in DC-DC converter
Hold the control circuit and method of power loss recovery.
Background technology
Using the DC-DC converter of bootstrap capacitor, small load or it is unloaded when, the switching node cycle becomes big, bootstrap capacitor
Charging ability reduces, cause first switch pipe can not normal ON/OFF, system operation irregularity or be stopped.
To solve the problem, a kind of method is to export increase dummy load in system, but can increase system power dissipation.It is another
Method is increase bootstrap capacitor voltage detecting circuit, when voltage is less than preset value, drags down switching node, is forced to bootstrap capacitor
Charging；This method can introduce larger power consumption, reduce system effectiveness.Also one kind is to increase multiple timing circuits, trigger,
And logic control circuit ensures the charge cycle of bootstrap capacitor and time, this method adds chip cost and circuit is set
Count complexity.
Circuit with bootstrap capacitor DC-DC converter as shown in Figure 1, mainly including circuits below：Opened including the first master
Pipe and the second main switch are closed, the drain electrode of first main switch connects the first power input, the source electrode of first switch pipe
Drain electrode with second switch pipe is connected, and tie point is set into switching node SW, the source ground of the second switch pipe, obtains electric current
Can through the drain electrode for flow direction second switch pipe, in addition to inductance, one end of the inductance and switch from the source electrode of second switch pipe
Node SW connections, the other end of inductance are load outputs, in addition to bootstrap capacitor and the second diode, the bootstrap capacitor
One end is connected with switching node SW, and the other end of bootstrap capacitor is sequentially connected the second diode and second source input, bootstrapping
The tie point of electric capacity and the second diode is node BS so that the electric current of second source output can only be from second source input stream
To bootstrap capacitor, the grid connection first switch tube drive circuit of first main switch, the grid of the second main switch connects
Second switch tube drive circuit is connect, the bootstrap capacitor is used to provide power supply to first switch tube drive circuit；Carried in normal band
In the case of, as shown in Fig. 2 switching node SW cyclically-varyings；First switch pipe is opened, and switching node SW rises, bootstrap capacitor
Voltage can not be mutated, and node BS voltages rise with SW；First switch pipe is closed, and second switch pipe is opened, and switching node SW declines,
Second source starts to start to charge up bootstrap capacitor when SW points are relatively low；Switching tube is with above-mentioned two steps circulation work, bootstrap capacitor electricity
Pressure maintains burning voltage, when converter load current diminishes, as shown in figure 3, switching node SW switch periods are elongated, bootstrap capacitor
Charging interval is shortened, and internal circuit electric charge consumption, bootstrap capacitor voltage is gradually reduced；When converter is changed into zero load, switch
Node SW switch periods are longer, and node SW can tend to be equal to output, and bootstrap capacitor lacks charge cycle, occurs needing first switch
The phenomenon that pipe is opened and can not opened, while output voltage progressively declines.The problem directly results in converter operation irregularity or stopped
Only work.
The content of the invention
Present invention solves the technical problem that it is to provide a kind of control for causing the fast quick-recovery of bootstrap capacitor voltage power down Cycle by Cycle
Circuit processed.
The technical solution adopted for the present invention to solve the technical problems is：One kind is applied to electricity of being booted in DC-DC converter
Hold power loss recovery control circuit, including the first main switch and the second main switch, the drain electrode connection of first main switch
First power input, the source electrode of first switch pipe are connected with the drain electrode of second switch pipe, and tie point is set into switching node SW,
The source ground of the second switch pipe so that electric current can pass through the leakage for flowing to second switch pipe from the source electrode of second switch pipe
Pole, in addition to inductance, one end of the inductance are connected with switching node SW, and the other end of inductance is load outputs, open including
Bootstrap capacitor and the second diode, one end of the bootstrap capacitor are connected with switching node SW, and the other end of bootstrap capacitor is successively
Connect the second diode and second source input so that the electric current of second source output can only flow to from second source input
Bootstrap capacitor, the grid connection first switch tube drive circuit of first main switch, the grid connection of the second main switch
Second switch tube drive circuit, the bootstrap capacitor are used to provide power supply to first switch tube drive circuit；
Also include d type flip flop, the Q output of the d type flip flop drives electricity by level shifting circuit and first switch pipe
Road is connected, and the Qn output ends of the d type flip flop are connected with second switch tube drive circuit, the D inputs connection of the d type flip flop
3rd input power, the d type flip flop triggering end connection CLK clock circuits, in addition to phase inverter and and gate circuit, it is described with
The output end of gate circuit is connected to the reset terminal of d type flip flop, the output end with the first input end of gate circuit and phase inverter
Connection, it is described that pulse width modulating signal, input and the CLK clocks of the phase inverter are connected with the second input of gate circuit
Circuit connects, in addition to is connected to the resistance of switching node SW and the first main switch grid.
The beneficial effects of the invention are as follows：The control circuit of the present invention can solve in DC-DC converter bootstrap capacitor because
Bootstrap capacitor power down is caused to cause the phenomenons of system output abnormality or system stalls, Yi Ji for small loaded/unloaded
After the node BS and switching node SW of bootstrap capacitor and the second diode short circuit revocations, bootstrap capacitor recovers to charge automatically, so as to
The normal operation of guarantee system, and the present invention need not export dummy load, load under-voltage detection, timing circuit, or increase volume
External trigger, so that simplify circuit design difficulty, strengthening system stability, meanwhile, the present invention realizes bootstrap capacitor for Cycle by Cycle
Voltage lifting, realize that the fast quick-recovery of system is stable.
Brief description of the drawings
Fig. 1 is the partial circuit schematic diagram of the DC-DC converter with bootstrap capacitor in the prior art.
Fig. 2 is the part of nodes ripple of the DC-DC converter with bootstrap capacitor in the prior art under larger steady load
Shape figure.
Fig. 3 is under small load or no-load condition, the part of the DC-DC converter with bootstrap capacitor is saved in the prior art
Point oscillogram.
Fig. 4 is the circuit diagram of this control circuit.
Fig. 5 is part of nodes voltage oscillogram of this control circuit under small load or no-load condition.
In figure mark for：First main switch 1, the second main switch 2, inductance 4, bootstrap capacitor 5, the second diode 6, D
Trigger 7, first switch tube drive circuit 8, second switch tube drive circuit 9, level shifting circuit 10, phase inverter 11 and door
Circuit 12, resistance 13.
Embodiment
The present invention is further described with reference to the accompanying drawings and detailed description.
As shown in Figures 4 and 5, a kind of control circuit for being applied to bootstrap capacitor power loss recovery in DC-DC converter, including
First main switch 1 and the second main switch 2, the drain electrode of first main switch 1 connect the first power input, and first opens
The source electrode for closing pipe is connected with the drain electrode of second switch pipe, and tie point is set into switching node SW, the source electrode of the second switch pipe
Ground connection, so that electric current can pass through the drain electrode for flowing to second switch pipe, in addition to inductance 4, the electricity from the source electrode of second switch pipe
One end of sense 4 is connected with switching node SW, and the other end of inductance 4 is load outputs, is opened including the pole of bootstrap capacitor 5 and the 2nd 2
Pipe 6, one end of the bootstrap capacitor 5 are connected with switching node SW, and the other end of bootstrap capacitor 5 is sequentially connected the second diode 6
With second source input, the tie point of the diode 6 of bootstrap capacitor 5 and second is set to node BS so that second source output
Electric current can only flow to bootstrap capacitor 5 from second source input, and the grid connection first switch pipe of first main switch 1 drives
Dynamic circuit 8, the grid connection second switch tube drive circuit 9 of the second main switch 2, the bootstrap capacitor 5 is used to open to first
Close tube drive circuit 8 and power supply is provided；
Also include d type flip flop 7, the Q output of the d type flip flop 7 is driven by level shifting circuit 10 and first switch pipe
Dynamic circuit 8 is connected, and the Qn output ends of the d type flip flop 7 are connected with second switch tube drive circuit 9, and the D of the d type flip flop 7 is defeated
Enter end connection the 3rd input power, the d type flip flop 7 triggering end connection CLK clock circuits, in addition to phase inverter 11 and with door
Circuit 12, the reset terminal that d type flip flop 7 is connected to gate circuit 12 output end, first input with gate circuit 12
End is connected with the output end of phase inverter 11, described to be connected pulse width modulating signal with the second input of gate circuit 12, described
The input of phase inverter 11 is connected with CLK clock circuits, in addition to is connected to switching node SW and the grid of the first main switch 1
Resistance 13.
The operation principle of foregoing circuit is as described below：If the output signal of the Q output of d type flip flop 7 is PWMH, D triggerings
The output signal of the Qn output ends of device 7 is PWML, and in the case of relatively large load, the pwm signal cycle is fixed, and control signal PWM is
Low level, the signal that the reset terminal of d type flip flop 7 receives also is low level always, clock CLK trailing edges triggering d type flip flop 7, is made
The output signal PWMH for obtaining d type flip flop 7 is high level, and PWML is low level, and signal PWMH opens through level-translation circuit and first
Close tube drive circuit 8 and produce first switch pipe drive signal V_Qh, first switch pipe is opened, and second switch pipe, which is in, closes shape
State, when control signal PWM is changed into high level by low level, CLK trailing edges are changed into low level, so that d type flip flop 7
The signal that reset terminal receives is changed into high level, and d type flip flop 7 resets, and signal PWML is changed into high level by low level so that second
Switch tube driving circuit 9 produces drive signal V_QL and opens second switch pipe, while is charged for bootstrap capacitor 5, circulates above-mentioned step
Suddenly, system is in stable state；In the case of small loaded/unloaded, the charge cycle of bootstrap capacitor 5 is elongated, the voltage drop of bootstrap capacitor 5
It is low；The voltage of bootstrap capacitor 5 can not provide driving force for first switch pipe, and the grid of first switch pipe is pulled down to out by resistance 13
Artis SW, first switch pipe are closed, and system output voltage reduces, and pwm signal is low level, and at the T1 moment, clock CLK declines
Control signal PWMH is produced along trigger, and bootstrap capacitor 5 can not provide driving, resistance 13 because of voltage power down for first switch pipe
First switch pipe closed mode is maintained, T2 moment clock CLK are in burst pulse high level, and pwm signal is still low level so that with door
High level is exported, d type flip flop 7 is resetted, control signal PWML output high level, second switch pipe produces drive signal V_QL and is
High level so that second switch pipe is opened, so as to charge for bootstrap capacitor 5, the T3 moment, if bootstrap capacitor 5 still can not be the
One switch tube driving circuit 8 provides driving, then repeatedly said process, control circuit of the invention can solve to convert in DC-DC
Bootstrap capacitor 5 causes system output abnormality or system to stop work because small loaded/unloaded causes the power down of bootstrap capacitor 5 in device
That makees shows, and after node BS and switching node SW the short circuit revocation of the diode 6 of bootstrap capacitor 5 and second, bootstrap capacitor 5 is certainly
Dynamic to recover charging, so as to ensure the normal operation of system, and the present invention need not export dummy load, load under-voltage detection, timing
Circuit, or increase additional flip-flop, so that simplify circuit design difficulty, strengthening system stability, meanwhile, the present invention is by week
Phase realizes the voltage lifting of bootstrap capacitor 5, realizes that the fast quick-recovery of system is stable.
The invention also discloses it is a kind of be applied to DC-DC converter in the power loss recovery of bootstrap capacitor 5 control method, when
In the case of relatively large load, the pwm signal cycle is fixed, and control signal PWM is low level, the signal that the reset terminal of d type flip flop 7 receives
Also it is low level always, clock CLK trailing edges trigger d type flip flop 7 so that the output signal PWMH of d type flip flop 7 is high level,
PWML is low level, and signal PWMH produces first switch pipe driving letter through level-translation circuit and first switch tube drive circuit 8
Number V_Qh, first switch pipe are opened, and second switch pipe is closed, when control signal PWM is changed into high electricity by low level
Usually, CLK trailing edges are changed into low level, so that the signal that the reset terminal of d type flip flop 7 receives is changed into high level, d type flip flop
7 reset, and signal PWML is changed into high level by low level so that second switch tube drive circuit 9 produces drive signal V_QL and opened
Second switch pipe is opened, while is charged for bootstrap capacitor 5, circulates above-mentioned steps, system is in stable state；
When in the case of small loaded/unloaded, the charge cycle of bootstrap capacitor 5 is elongated, the voltage of bootstrap capacitor 5 reduces；Bootstrapping electricity
Driving force can not be provided for first switch pipe by holding 5 voltages, and the grid of first switch pipe is pulled down to switching node SW by resistance 13,
First switch pipe is closed, and system output voltage reduces, and pwm signal is low level, when clock CLK trailing edges trigger produces control
Signal PWMH, and bootstrap capacitor 5 can not provide driving, the maintenance first switch pipe of resistance 13 pass because of voltage power down for first switch pipe
Closed state, when clock CLK is in burst pulse high level, pwm signal is still low level so that exports high level with door, D is triggered
Device 7 resets, and control signal PWML output high level, it is high level that second switch pipe, which produces drive signal V_QL, so that second opens
Close pipe to open, so as to charge for bootstrap capacitor 5, if following instant bootstrap capacitor 5 still can not be first switch tube drive circuit 8
Driving is provided, then repeatedly said process.
Particular embodiments described above, the purpose of the present invention, technical scheme and beneficial effect are carried out further in detail
Describe in detail it is bright, should be understood that the foregoing is only the present invention specific embodiment, be not intended to limit the invention, it is all
Within the spirit and principles in the present invention, any modification, equivalent substitution and improvements done etc., it should be included in the guarantor of the present invention
Within the scope of shield.
Claims (2)
1. it is a kind of be applied to DC-DC converter in bootstrap capacitor power loss recovery control circuit, including the first main switch (1) and
Second main switch (2), the drain electrode of first main switch (1) connect the first power input, the source electrode of first switch pipe
Drain electrode with second switch pipe is connected, and tie point is set into switching node SW, the source ground of the second switch pipe so that electricity
Stream can from the source electrode of second switch pipe by flow to the drain electrode of second switch pipe, in addition to inductance (4), the one of the inductance (4)
End is connected with switching node SW, and the other end of inductance (4) is load outputs, is opened including bootstrap capacitor (5) and the second diode
(6), one end of the bootstrap capacitor (5) is connected with switching node SW, and the other end of bootstrap capacitor (5) is sequentially connected the two or two pole
Manage (6) and second source input so that the electric current of second source output can only flow to bootstrap capacitor from second source input
(5), the grid connection first switch tube drive circuit (8) of first main switch (1), the grid of the second main switch (2)
Second switch tube drive circuit (9) is connected, the bootstrap capacitor (5) is used to provide power supply to first switch tube drive circuit (8)；
It is characterized in that：
Also include d type flip flop (7), the Q output of the d type flip flop (7) passes through level shifting circuit (10) and first switch pipe
Drive circuit (8) is connected, and the Qn output ends of the d type flip flop (7) are connected with second switch tube drive circuit (9), the D triggerings
The D inputs of device (7) connect the 3rd input power, and the triggering end of the d type flip flop (7) connects CLK clock circuits, in addition to anti-
Phase device (11) and described with gate circuit (12), the reset terminal that d type flip flop (7) are connected to gate circuit (12) output end
It is connected with the first input end of gate circuit (12) with the output end of phase inverter (11), described and the second input of gate circuit (12)
Pulse width modulating signal is connected, the input of the phase inverter (11) is connected with CLK clock circuits, in addition to is connected to switch
Node SW and the first main switch (1) grid resistance (13).
A kind of 2. control method for being applied to bootstrap capacitor power loss recovery in DC-DC converter, it is characterised in that：Will including right
Seek a kind of control circuit for being applied to bootstrap capacitor power loss recovery in DC-DC converter described in 1；
When in the case of relatively large load, the pwm signal cycle is fixed, control signal PWM is low level, the reset terminal of d type flip flop (7)
The signal received is also low level always, and clock CLK trailing edges trigger d type flip flop (7) so that the output signal of d type flip flop (7)
PWMH is high level, and PWML is low level, and signal PWMH produces the through level-translation circuit and first switch tube drive circuit (8)
One switching tube drive signal V_Qh, first switch pipe are opened, and second switch pipe is closed, when control signal PWM is by low
When level transitions are high level, CLK trailing edges are changed into low level, so that the signal that the reset terminal of d type flip flop (7) receives becomes
For high level, d type flip flop (7) resets, and signal PWML is changed into high level by low level so that second switch tube drive circuit
(9) produce drive signal V_QL and open second switch pipe, while charged for bootstrap capacitor (5), circulate above-mentioned steps, system is in
Stable state；
When in the case of small loaded/unloaded, bootstrap capacitor (5) charge cycle is elongated, bootstrap capacitor (5) voltage reduces；Bootstrapping electricity
Driving force can not be provided for first switch pipe by holding (5) voltage, and the grid of first switch pipe is pulled down to joint by resistance (13)
Point SW, first switch pipe are closed, and system output voltage reduces, and pwm signal is low level, when clock CLK trailing edges trigger produces
Raw control signal PWMH, and bootstrap capacitor (5) be because voltage power down can not provide driving for first switch pipe, resistance (13) maintenance the
One switching tube closed mode, when clock CLK is in burst pulse high level, pwm signal is still low level so that exports high electricity with door
It is flat, d type flip flop (7) is resetted, control signal PWML output high level, second switch pipe produces drive signal V_QL as high electricity
It is flat so that second switch pipe is opened, so as to be charged for bootstrap capacitor (5), if following instant bootstrap capacitor (5) still can not be the
One switch tube driving circuit (8) provides driving, then repeatedly said process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710868710.XA CN107592013A (en) | 2017-09-22 | 2017-09-22 | Control circuit and method applied to bootstrap capacitor power loss recovery in DC DC converters |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710868710.XA CN107592013A (en) | 2017-09-22 | 2017-09-22 | Control circuit and method applied to bootstrap capacitor power loss recovery in DC DC converters |
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| Publication Number | Publication Date |
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| CN107592013A true CN107592013A (en) | 2018-01-16 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201710868710.XA Pending CN107592013A (en) | 2017-09-22 | 2017-09-22 | Control circuit and method applied to bootstrap capacitor power loss recovery in DC DC converters |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110808573A (en) * | 2019-10-29 | 2020-02-18 | 杰华特微电子（杭州）有限公司 | Switching power supply control circuit, control method and switching power supply |
| CN111478605A (en) * | 2020-04-15 | 2020-07-31 | 深圳市稳先微电子有限公司 | Synchronous rectification control chip and AC-DC system |
| CN111987892A (en) * | 2019-05-22 | 2020-11-24 | 维谛公司 | Drive control method, device, equipment and medium of switching power supply |
| CN113193732A (en) * | 2021-04-27 | 2021-07-30 | 成都稳海半导体有限公司 | Self-adaptive charging bootstrap power supply |
| CN113258764A (en) * | 2021-06-22 | 2021-08-13 | 浙江大学 | High-voltage driving circuit and power module |
| CN113541453A (en) * | 2021-07-05 | 2021-10-22 | 无锡安趋电子有限公司 | High-side bootstrap power supply control system in GaN power tube half-bridge drive |
| CN117155126A (en) * | 2023-03-14 | 2023-12-01 | 荣耀终端有限公司 | Terminal equipment and control method |
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2017
- 2017-09-22 CN CN201710868710.XA patent/CN107592013A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111987892A (en) * | 2019-05-22 | 2020-11-24 | 维谛公司 | Drive control method, device, equipment and medium of switching power supply |
| CN110808573A (en) * | 2019-10-29 | 2020-02-18 | 杰华特微电子（杭州）有限公司 | Switching power supply control circuit, control method and switching power supply |
| CN111478605A (en) * | 2020-04-15 | 2020-07-31 | 深圳市稳先微电子有限公司 | Synchronous rectification control chip and AC-DC system |
| CN111478605B (en) * | 2020-04-15 | 2021-07-06 | 深圳市稳先微电子有限公司 | Synchronous rectification control chip and AC-DC system |
| CN113193732A (en) * | 2021-04-27 | 2021-07-30 | 成都稳海半导体有限公司 | Self-adaptive charging bootstrap power supply |
| CN113258764A (en) * | 2021-06-22 | 2021-08-13 | 浙江大学 | High-voltage driving circuit and power module |
| CN113541453A (en) * | 2021-07-05 | 2021-10-22 | 无锡安趋电子有限公司 | High-side bootstrap power supply control system in GaN power tube half-bridge drive |
| CN113541453B (en) * | 2021-07-05 | 2023-02-03 | 无锡安趋电子有限公司 | High-side bootstrap power supply control system in GaN power tube half-bridge drive |
| CN117155126A (en) * | 2023-03-14 | 2023-12-01 | 荣耀终端有限公司 | Terminal equipment and control method |
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