CN103675425B - Self-adaptive quasi-resonance valley detection circuit of flyback switching power supply - Google Patents

Self-adaptive quasi-resonance valley detection circuit of flyback switching power supply Download PDF

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Publication number
CN103675425B
CN103675425B CN201210349383.4A CN201210349383A CN103675425B CN 103675425 B CN103675425 B CN 103675425B CN 201210349383 A CN201210349383 A CN 201210349383A CN 103675425 B CN103675425 B CN 103675425B
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quasi
detection circuit
resonance
circuit
signal
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CN103675425A (en
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张翌
张义
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Shangahi Duty Cycle Semiconductor Co., Ltd.
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SHANGAHI DUTY CYCLE SEMICONDUCTOR CO Ltd
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Abstract

The invention discloses a self-adaptive quasi-resonance valley detection circuit of a flyback switching power supply. The self-adaptive quasi-resonance valley detection circuit comprises a secondary side inductance current zero-cross detection circuit, an FB (full bridge) voltage zero-cross detection circuit, a signal processing circuit and a timing circuit. The quasi-resonance valley occurring time can be predicted through the timing circuit according to the periodicity of quasi-resonance signals by detecting the secondary-side inductance current zero-cross signal of the flyback switching power supply as well as the voltage zero-cross signal on an auxiliary winding voltage divider of the flyback switching power supply, thereby realizing quasi-resonance valley conduction of the flyback switching power supply. The self-adaptive quasi-resonance valley detection circuit provided by the invention can be used for not only the flyback switching power supply, but also a buck switching power supply, a boost switching power supply, a buck-boost switching power supply and so on without being affected by the parameter changes of peripheral devices of the flyback switching power supply.

Description

A kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit
Technical field
The present invention relates to a kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit, is mainly used in inverse-excitation type Switching Power Supply (or voltage-dropping type, booster type, buck-boost type) quasi-resonance trough conduction mode, so as to reduce switching loss and raising EMI performances.
Background technology
In order to reduce the power attenuation of Switching Power Supply and improve electromagnetic interference (EMI) performance, Sofe Switch is because have low Conduction loss and be widely used.
By taking quasi-resonance inverse-excitation type switch power-supply as an example, such as Fig. 1, a typical quasi-resonance inverse-excitation type switch power-supply includes: Transformer and output rectifier and filter 101, a feedback resistive network 102, a former limit pwm chip 103, one NMOS power switch pipes 105, and a resistance 106.
Transformer and output rectifier and filter 101 are used to for exchange input electric energy to be transformed into secondary output VOUT.Its The former limit of middle transformer is coupled to input power VIN.The secondary of transformer is coupled to output commutation diode D1 and filter capacitor C1.The assists winding of transformer is coupled to feedback resistive network 102.
Feedback resistive network 102 is used to produce signal VFB, and it feeds back output electricity when NMOS power switch pipes 105 are closed VOUT is to former limit pwm chip 103 for pressure.
Feedback signal VFB that former limit pwm chip 103 is produced according to feedback resistive network 102, by quasi-resonance trough Detection circuit 301 produce VALLEY signals to PWM logic circuits 303 setting signal end S, as a result by drive circuit 304 from And uprise GATE signals.Signal GATE should uprise to reduce NMOS when quasi-resonance signal VFB reaches its trough the lowest point Conduction loss on power switch pipe 105.At this moment NMOS power switch pipes 105 are turned on, and primary electrical electrification is produced on resistance 106 The induced signal VCS of stream.VCS is produced through the former limit inductance peak current detection circuit 302 of former limit pwm chip 103 The reset signal end R of RESET signal to PWM logic circuits 303.Its result passes through drive circuit 304 so that GATE signals become Low, at this moment NMOS power switch pipes 105 end, and transformer assists winding output voltage AUX, and feedback resistive network 102 feedback signals VFB for generating are proportional with the drain voltage of NMOS power switch pipes 105.
Turn off thus by the conducting of periodic NMOS power switch pipes 105, it is given birth to by former limit pwm chip 103 Into the control of GATE signals, it is defeated that exchange input VIN electric energy is converted to direct current by transformer and output rectifier and filter 101 Go out VOUT energy.
But want to control the moment of the conducting of NMOS power switch pipes 105 just in the trough of quasi-resonance feedback voltage V FB The lowest point is not easy to.Shadow of the detection circuit of existing inverse-excitation type switch power-supply quasi-resonance trough by the change of peripheral source device parameters Ring, for example, primary surveys the inductance value of inductance, the parasitic capacitance of power switch pipe, parasitic capacitance of transformer etc..Its result be During batch production, it is impossible to ensure all to turn in the trough of quasi-resonance, so as to affect performance.
A kind of detection circuit such as Fig. 2 of existing inverse-excitation type switch power-supply quasi-resonance trough. it is the circuit by periphery Quasi-resonance trough (a) is detected indirectly by means of inverse-excitation type switch power-supply assists winding.B () to (d) shows key waveforms.Da It is that a diode is used for clamper " Sync " signal so as to which voltage is not less than -0.3V.Ca, together with the Ra of resitstance voltage divider, Rb and Rc, generates the Vsync signals of a constant delay time constant.There is the time delay of about 200ns in view of the inside of chip (FSQ510 of fairchild company), quasi-resonance valley detection can reach the time of low valve valve VSL and add by adjusting Vsync voltages The delay of upper chip internal 200ns is realizing.
This quasi-resonance valley detection circuit receives external component, the such as inductance value of primary side inductance, power switch pipe The impact of parasitic capacitance, the parasitic capacitance of transformer etc., therefore can be compared with only in the case of known inductance value and parasitic capacitance Good work, (but it still changes with the change of circuit board and the change of inductance value).In order to be able to be applied to more applications, need Set up external circuit to adjust different time delays, to reach the purpose of quasi-resonance valley detection.
But, this extra outer detecting circuit increased the quantity and PCB sizes of components and parts, thus increased cost.
Another existing quasi-resonance valley detection circuit (US20080116870) by assists winding quasi-resonance signal and Its postpones signal is compared relatively to realize valley detection.Its schematic diagram is as shown in figure 3, the oscillogram of wherein each point is as shown in Figure 4.
In Fig. 3, in voltage translator circuit 205, signal delay follower 206 produces the postpones signal of a V1 voltages V2.V2 voltages are lifted to V3.V1 reflects the voltage drop in primary side power switch tube S W1.Comparator 208 compare V1 and It is delayed by the voltage V3 with lifting, so as to produce quasi-resonance trough signal Valley.When V1 is in trough, Valley signals by Low to high saltus step.
Likewise, because the delay of the V1 signals of the generation of signal delay follower 206 can not track the change of outer member, Such as the primary inductance value for surveying inductance, the parasitic capacitance of power switch pipe, parasitic capacitance of transformer etc., this valley detection circuit is same The impact of sample also peripheral component parameter, so as to cause valley detection incorrect.
In sum, one is needed not by the quasi-resonance valley detection circuit of peripheral component parametric variations, it should With more preferable adaptivity, while do not increase any peripheral circuit, to reach more preferable economy.
The content of the invention
For problems of the prior art, the purpose of the present invention is:A kind of adaptive flyback switching electricity is provided Source quasi-resonance valley detection circuit, it can not be by peripheral component parametric variations and with more preferable adaptivity, together When do not increase any peripheral circuit.
The technical solution adopted for the present invention to solve the technical problems is:
A kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit, the quasi-resonance valley detection circuit bag Include:Secondary side inductive current zero cross detection circuit, FB voltage zero-crossing detection circuits, signal processing circuit and timing circuit, wherein, The input of secondary side inductive current zero cross detection circuit and FB voltage zero-crossing detection circuits receives a voltage VFB, secondary side electricity Output end TRB of inducing current zero cross detection circuit is connected to the first input end of signal processing circuit, FB voltage zero-cross detection electricity The output end on road is connected to the second input of signal processing circuit, and two output ends Q1 of signal processing circuit and VALLEY divide It is not connected to the corresponding input of timing circuit, it is the 3rd defeated that output end Q2 of timing circuit is connected to signal processing circuit Enter end, output end VALLEY of the signal processing circuit exports a signal.
The voltage VFB is provided by assists winding divider.
The secondary side inductive current zero cross detection circuit detects secondary side inductive current by detection voltage VFB Zero-acrross ing moment, so that it is determined that the start time of quasi-resonance.
The FB voltage zero-crossing detection circuits detect the zero-acrross ing moment of FB voltages by detection voltage VFB, so that it is determined that Moment of the AUX quasi-resonances signal through a quarter cycle.
When the signal processing circuit is by the zero passage of the zero-acrross ing moment of the secondary side inductive current and the FB voltages Carve the time used by the detection output AUX quasi-resonances signal experience a quarter cycle.
The timing circuit experiences a quarter by receiving the AUX quasi-resonances signal that the signal processing circuit is detected Time used by cycle, further calculate moment of the AUX quasi-resonances signal through 1/2nd cycles.
The AUX quasi-resonances signal is exactly AUX quasi-resonances signal through trough paddy through the moment in 1/2nd cycles The moment at bottom.
The signal that output end VALLEY by signal processing circuit is exported is used to control the lowest point of power switch pipe leads It is logical, so as to realize low conduction loss and high EMI performances.
The invention has the beneficial effects as follows:Because quasi-resonance valley detection circuit of the present invention is by detecting secondary side inductive current Zero crossing and FB voltage over zero and the Q1 signals that produce can effectively track the change of peripheral component parameter, such as primary The inductance value of side inductance, the parasitic capacitance of power switch pipe, parasitic capacitance of transformer etc., so quasi-resonance trough of the present invention inspection Slowdown monitoring circuit has the change to the primary inductance value for surveying inductance, the parasitic capacitance of power switch pipe, the parasitic capacitance of transformer etc. Adaptivity, not changed by it is affected and remains to make power switch pipe effectively in the valley conduction of quasi-resonance waveform.
At the same time quasi-resonance valley detection circuit of the present invention does not increase any peripheral circuit yet, so as to save into This.
Description of the drawings
Fig. 1 is a typical quasi-resonance inverse-excitation type switch power-supply circuit;
Fig. 2 is the detection circuit and its oscillogram of an existing inverse-excitation type switch power-supply quasi-resonance trough;
Fig. 3 is the detection circuit of another existing inverse-excitation type switch power-supply quasi-resonance trough;
Fig. 4 is to illustrate the oscillogram of the implementing circuit shown in Fig. 3;
Fig. 5 is the circuit block diagram of the present invention;
Fig. 6 is to illustrate the oscillogram of circuit shown in Fig. 5.
Specific embodiment
In conjunction with the accompanying drawings, the present invention is further detailed explanation.These accompanying drawings are simplified schematic diagram, only with The basic structure of the illustration explanation present invention, therefore it only shows the composition relevant with the present invention.
Presently in connection with accompanying drawing 5, the present invention is further detailed explanation.Quasi-resonance valley detection circuit 301 of the present invention is wrapped Inverse-excitation type switch power-supply secondary side inductive current zero cross detection circuit 401 is included, on inverse-excitation type switch power-supply assists winding divider Voltage zero-crossing detection circuit 402, a timing circuit 403, an and signal processing circuit 404.
When secondary side inductive current is discharged into zero, secondary side inductive current zero cross detection circuit 401 can produce one On along saltus step TRB signals, deliver to signal processing circuit 404.The upper edge of this TRB signal correspond to rising for AUX quasi-resonance signals Begin the moment.At the same time, when AUX voltages fall to zero, FB zero cross detection circuits 402 can be produced on one along the TRAMP of saltus step Signal, delivers to signal processing circuit 404.The upper edge of this TRAMP signal correspond to AUX quasi-resonances signal through a quarter cycle When moment.Signal processing circuit 404 according to receive TRB and TRAMP signal generation AUX quasi-resonances signal experience four/ The Q1 signals of time used by one cycle, deliver to timing circuit 403 as the reference signal of timing.Then the foundation of timing circuit 403 This chronograph reference signal Q1 predicts moment of the AUX quasi-resonances signal through 1/2nd cycles through Timing Processing, so as to produce Along the Q2 signals of saltus step on raw one, and loopback Q2 signals are to signal processing circuit 404.Q2 is upper to be exactly along the saltus step corresponding moment AUX quasi-resonant voltages are at trough the lowest point, thus signal processing circuit 404 produces VALLEY signals according to Q2 signals, send To the setting signal end S of PWM logic circuits 303, its result by drive circuit 304 so that GATE signals are uprised, NMOS work( Rate switching tube 105 is turned on.The such moment of the conducting of NMOS power switch pipes 105 just corresponding A UX (or NMOS power switch pipes 105 drain voltages) quasi-resonance signal at the trough the lowest point moment, so as to realize quasi-resonance valley conduction.Above-mentioned quasi-resonance trough inspection The key point waveform of slowdown monitoring circuit 301 is as shown in Figure 6.
Within the quasi-resonance time of AUX signals, quasi-resonance cycle time is determined by following equation
Wherein Tring is quasi-resonance cycle time, and Lp is transformer primary side inductance value, and Cpar is NMOS power switch pipes The summation of all parasitic capacitances of 105 drain electrodes, including the parasitic capacitance of power switch pipe 105, parasitic capacitance of transformer etc..By Quasi-resonance Period Formula learns that the change of Lp and Cpar can cause quasi-resonance the lowest point for different pcb board and different NMOS Power switch pipe is different.
Quasi-resonance valley detection circuit 301 of the present invention is by detection secondary side inductive current zero crossing and FB voltage zero-cross The Q1 signals put and produce can effectively track the change of Lp and Cpar.For example, if Lp/Cpar becomes big, Q1 will be elongated, Vice versa.Then according to the time of Q1, using the cyclophysis of quasi-resonance signal, infer the appearance of quasi-resonance trough when Carve, so as to the trough for realizing NMOS power switch pipes 105 is turned on.As can be seen here, quasi-resonance valley detection circuit 301 of the present invention has There is the adaptivity of the change to Lp and Cpar, not changed by it is affected and remain to make power switch pipe effectively in quasi-resonance The valley conduction of waveform.At the same time quasi-resonance valley detection circuit of the present invention does not increase any peripheral circuit yet, so as to save Cost is saved.
Scheme disclosed in this invention is equally applicable to adjusting and voltage-reduction switch power supply BUCK, step-up switching power supply BOOST, rises Adjusting and voltage-reduction switch power supply Buck-Boost etc..
The principal character and innovative point for only describing this programme is shown above.Those skilled in the art is it should be appreciated that originally Scheme is not restricted to the described embodiments.On the premise of without departing from the innovation point and protection domain, this programme also has various Change, these changes and improvements are fallen within the claimed scope of this programme.The claimed scope of this programme is by appended Claims and its equivalent limit.

Claims (7)

1. a kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit, it is characterised in that the quasi-resonance trough Detection circuit includes:Secondary side inductive current zero cross detection circuit, FB voltage zero-crossing detection circuits, signal processing circuit and timing Circuit, wherein, the input of secondary side inductive current zero cross detection circuit and FB voltage zero-crossing detection circuits receives a voltage VFB, output end TRB of secondary side inductive current zero cross detection circuit is connected to the first input end of signal processing circuit, and FB is electric The output end of pressure zero cross detection circuit is connected to the second input of signal processing circuit, an output end of signal processing circuit Q1 is connected to first input of timing circuit, and another output end VALLEY of signal processing circuit is connected to timing circuit Second input, output end Q2 of timing circuit is connected to the 3rd input of signal processing circuit, the signal transacting Output end VALLEY of circuit also exports a signal;The secondary side inductive current zero cross detection circuit passes through detection voltage VFB, To detect the zero-acrross ing moment of secondary side inductive current, so that it is determined that the start time of quasi-resonance.
2. a kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit as claimed in claim 1, its feature exists In the voltage VFB is provided by assists winding divider.
3. a kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit as claimed in claim 1, its feature exists In the FB voltage zero-crossing detection circuits detect the zero-acrross ing moment of FB voltages by detection voltage VFB, so that it is determined that AUX is accurate Moment of the resonance signal through a quarter cycle.
4. a kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit as claimed in claim 3, its feature exists In the signal processing circuit is by the zero-acrross ing moment of the secondary side inductive current and the zero-acrross ing moment detection of the FB voltages Time used by the output AUX quasi-resonances signal experience a quarter cycle.
5. a kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit as claimed in claim 4, its feature exists In the timing circuit experiences a quarter cycle by receiving the AUX quasi-resonances signal that the signal processing circuit is detected Time used, further calculate moment of the AUX quasi-resonances signal through 1/2nd cycles.
6. a kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit as claimed in claim 5, its feature exists In, the AUX quasi-resonances signal through the moment in 1/2nd cycles be exactly AUX quasi-resonances signal through trough the lowest point when Carve.
7. a kind of adaptive inverse-excitation type switch power-supply quasi-resonance valley detection circuit as claimed in claim 1, its feature exists In, the signal of the output end VALLEY output of the signal processing circuit is used to control the valley conduction of power switch pipe, so as to Realize low conduction loss and high EMI performances.
CN201210349383.4A 2012-09-18 2012-09-18 Self-adaptive quasi-resonance valley detection circuit of flyback switching power supply Expired - Fee Related CN103675425B (en)

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* Cited by examiner, † Cited by third party
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CN104702117B (en) * 2014-12-26 2018-09-18 矽力杰半导体技术(杭州)有限公司 Inverse-excitation converting circuit, the ON-OFF control circuit for being applicable in the circuit, the lowest point detection circuit and method
CN105262333B (en) * 2015-12-02 2017-11-03 成都启臣微电子股份有限公司 A kind of quasi-resonance flyback controller and control method
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CN109001523B (en) * 2018-08-02 2020-11-20 西安鼎芯微电子有限公司 Wave trough detection device of alternating current-direct current converter
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6958920B2 (en) * 2003-10-02 2005-10-25 Supertex, Inc. Switching power converter and method of controlling output voltage thereof using predictive sensing of magnetic flux
CN101498747A (en) * 2008-12-25 2009-08-05 四川登巅微电子有限公司 Wave crest and wave trough detection method and circuit
CN102097960A (en) * 2010-10-01 2011-06-15 崇贸科技股份有限公司 Controller for power converter and control method for quasi resonant power converter
CN102307019A (en) * 2011-08-12 2012-01-04 浙江昱能光伏科技集成有限公司 Quasi-resonant control circuit of inverter
CN202837384U (en) * 2012-09-18 2013-03-27 张翌 Self-adapting flyback switching power supply quasi-resonance trough detection circuit

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW200824240A (en) * 2006-11-24 2008-06-01 Richtek Technology Corp A waveform valley estimation circuit of a switching component and the method thereof
JP2009100557A (en) * 2007-10-17 2009-05-07 Kawasaki Microelectronics Kk Power supply system and switching method therefor
CN102082521B (en) * 2010-10-29 2013-01-09 西安英洛华微电子有限公司 Circuit for accurately detecting resonance trough
CN102121950A (en) * 2010-12-21 2011-07-13 厦门拓能信息科技有限公司 Method for zero crossing detection of adaptive alternating-current voltage
CN102243263B (en) * 2011-04-08 2015-05-13 苏州路之遥科技股份有限公司 Alternating current value detection and current zero crossing point detection circuit

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6958920B2 (en) * 2003-10-02 2005-10-25 Supertex, Inc. Switching power converter and method of controlling output voltage thereof using predictive sensing of magnetic flux
CN101498747A (en) * 2008-12-25 2009-08-05 四川登巅微电子有限公司 Wave crest and wave trough detection method and circuit
CN102097960A (en) * 2010-10-01 2011-06-15 崇贸科技股份有限公司 Controller for power converter and control method for quasi resonant power converter
CN102307019A (en) * 2011-08-12 2012-01-04 浙江昱能光伏科技集成有限公司 Quasi-resonant control circuit of inverter
CN202837384U (en) * 2012-09-18 2013-03-27 张翌 Self-adapting flyback switching power supply quasi-resonance trough detection circuit

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