CN102055175A - Fast output short-circuit protection device and method used at primary side of semi-resonant converter - Google Patents

Fast output short-circuit protection device and method used at primary side of semi-resonant converter Download PDF

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CN102055175A
CN102055175A CN2009101979846A CN200910197984A CN102055175A CN 102055175 A CN102055175 A CN 102055175A CN 2009101979846 A CN2009101979846 A CN 2009101979846A CN 200910197984 A CN200910197984 A CN 200910197984A CN 102055175 A CN102055175 A CN 102055175A
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semi
signal
output short
circuit protection
output
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CN2009101979846A
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林梓诚
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上海立隆微电子有限公司
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Abstract

The invention discloses a fast output short-circuit protection device used at the primary side of a semi-resonant converter. The semi-resonant converter comprises a power switch which is switched by a control signal. The fast output short-circuit protection device is characterized by comprising a valley value detector and an output short-circuit judgment circuit, wherein the valley value detector is connected with the power switch and is used for detecting the voltage valley value of the power switch so as to generate a valley value signal, and the output short-circuit judgment circuit is connected with the valley value detector and is used for sending out a fault signal when the valley value signal is not received in an endurable period of time. The fast output short-circuit protection device and method used at the primary side of a semi-resonant converter provided by the invention have the advantage of rapid response when the semi-resonant converter is in an output short circuit state.

Description

用于半共振转换器一次侧的快速输出短路保护装置及方法技术领域 A quick output short circuit protection device and method for semi-resonant converter Field of the side

[0001] 本发明涉及一种半共振转换器,具体地说,是一种用于半共振转换器一次侧的快速输出短路保护装置及方法。 [0001] The present invention relates to a semi-resonant converter, in particular, it is a rapid output short circuit protection device and method for semi-resonant primary side of the converter is used. 背景技术 Background technique

[0002] 图1为已知的半共振驰返式转换器,其中变压器Tl具有一次侧线圈Lp连接在电源Vin及功率开关Sl之间、二次侧线圈Ls经二极管Do连接到输出端No、以及辅助线圈Laux经二极管Daux连接到电容Caux,光耦合器12监视输出电压Vo以提供回授信号Vfb 给脉宽调变(Pulse Width Modulation ;P丽)控制器10的回授端FB,以及PWM控制器10经输出端fete提供控制信号Vgs切换功率开关Sl以将输入电压Vin转换为输出电压Vo,以及经检测端Vdet监视辅助线圈Laux上的电压Vaux。 [0002] Figure 1 is a known semi-resonant flyback converter in which the transformer Tl has a primary coil Lp connected between the power source Vin and the power switch Sl, via the secondary winding Ls connected to the output diode Do No, Laux and an auxiliary coil connected to the capacitor via the diode Daux Caux, optical coupler 12 monitors the output voltage Vo to provide the feedback signal Vfb to the PWM (Pulse width modulation; P Li) controller feedback terminal FB 10, and a PWM the controller 10 through the output terminal providing a control signal Vgs fete switching power switch Sl to the input voltage Vin into an output voltage Vo, and by monitoring the voltage detection terminal Vdet auxiliary winding Vaux on Laux. 当半共振驰返式转换器的输出端Vo 短路时,变压器Tl将饱和,这使得功率开关Sl承受非常大的电流及电压应力。 When the semi-resonant flyback converter output terminal Vo short circuit, transformer Tl to saturate it such that the power switch Sl withstand very large voltage and current stress.

[0003] 在已知的PWM控制器10中,并未直接从二次侧检测输出电压Vo。 [0003] In the known PWM controller 10, not directly from the secondary side of the detection output voltage Vo. 已知的输出短路保护是靠过载保护或回授开路保护(feedback open protection)来达成,然而这些方法都需要很长的抗尖峰脉冲(deglitch)时间来避免在负载瞬时期间造成误触发。 Output short circuit protection is known by overload or open circuit protection feedback (feedback open protection) to achieve, but these methods require a long Deglitch (deglitch) time to avoid false triggering during a load transient. 图2为已知的输出短路保护电路,其包括比较器14及延迟电路16。 FIG 2 is a known output short circuit protection circuit 14 includes a comparator 16 and a delay circuit. 比较器14比较回授信号Vfb及参考电压Vref产生比较信号&给延迟电路16。 The comparator 14 compares the feedback signal Vfb and the reference voltage Vref & generate a comparison signal to the delay circuit 16. 当半共振驰返式转换器的输出端Vo短路时,回授信号Vfb上升,在回授信号Vfb大于参考电压Vref时,比较器14输出高准位的比较信号&。 When the semi-resonant flyback converter output terminal Vo short circuit, the feedback signal Vfb rises when the feedback signal Vfb is greater than the reference voltage Vref, the comparator 14 outputs a high-level comparison signal &. 由于在负载瞬时期间,回授信号Vfb也可能大于参考信号Vref,因此为了避免误触发,延迟电路16只有在回授信号Vfb持续大于参考电压Vref —段时间后才会触发故障信号Fault去关闭PWM控制器10。 Since, during load transient, the feedback signal Vfb is greater than the reference signal Vref is also possible, therefore in order to avoid false triggering, delay circuit 16 only when the feedback signal Vfb duration greater than the reference voltage Vref - after a period of time will trigger a failure signal to close the PWM Fault The controller 10. 这段延迟的时间超过30毫秒(ms),不但造成输出短路保护的反应变慢,也导致更多的功率损失。 The delay time exceeds 30 milliseconds (MS), output short circuit protection only cause a slower reaction, but also results in more power loss.

[0004] 因此已知的输出短路保护装置存在着上述种种不便和问题。 [0004] Thus the known output short circuit protection device is present in said inconveniences and problems. 发明内容 SUMMARY

[0005] 本发明的目的,在于提出一种快速输出短路保护装置及方法。 [0005] The object of the present invention is to provide a rapid output short circuit protection device and method.

[0006] 本发明的另一目的,在于提出一种应用在半共振转换器一次侧的快速输出短路保护装置及方法。 [0006] Another object of the present invention is to provide fast output short-circuit protection device and method for applying the primary side of the semi-resonant converter.

[0007] 为实现上述目的,本发明的技术解决方案是: [0007] To achieve the above object, the technical solution of the invention is:

[0008] 一种应用在半共振转换器一次侧的快速输出短路保护装置,所述半共振转换器包含功率开关受一控制信号切换,其特征在于所述快速输出短路保护装置包括: [0008] One application in a fast output short-circuit protection device side semi-resonant converter, said semi-resonant converter includes a power switch by a control signal, wherein said rapid output short circuit protection device comprising:

[0009] 谷值检测器连接所述功率开关,检测所述功率开关上的电压谷值而产生谷值信号;以及 [0009] valley detector is connected to the power switch, the voltage detecting valley on the power switch to generate a valley signal;

[0010] 输出短路判断电路连接所述谷值检测器,当持续一段延迟时间都未接收到所述谷值信号时,送出故障信号。 [0010] Analyzing the output short circuit connected to said trough value detector, a delay time duration when none of the valley received signal, sends the fault signal.

[0011] 本发明的应用在半共振转换器一次侧的快速输出短路保护装置还可以采用以下的技术措施来进一步实现。 [0011] Application of the present invention is a rapid output short circuit protection device side may also be the following technical measures employed to achieve further semi-resonant converter.

[0012] 前述的保护装置,其中所述延迟时间包括所述控制信号的数个周期。 [0012] the protective device, wherein said delay time of said control signal comprises a plurality of cycles.

[0013] 前述的保护装置,其中所述输出短路判断电路包括多个串接的正反器,每一所述正反器具有正相输出端、反相输出端、数据端连接所述反相输出端、清除端供接收所述谷值信号、以及频率端供接收所述控制信号或连接前一级正反器的反相输出端,所述故障信号由所述多个正反器中最后一级的正相输出端提供。 [0013] the protective device, wherein said determination circuit comprises a plurality of output short-flip-flops connected in series, each of said flip-flop having a positive-phase output terminal, an inverting output terminal, a data terminal connected to the inverting an output terminal, the inverted clear terminal for receiving the output of said trough value signal, and the frequency front end for receiving said control signal or a flip-flop is connected, the fault signal from said plurality of flip-flops in the last providing a positive-phase output terminal of.

[0014] 一种应用在半共振转换器一次侧的快速输出短路保护方法,所述半共振转换器包含功率开关受一控制信号切换,其特征在于所述快速输出短路保护方法包括下列步骤: [0014] One application side of the primary fast semi-resonant converter output short circuit protection method, the semi-resonant converter includes a power switch by a switching control signal, characterized in that said rapid output short circuit protection method comprising the steps of:

[0015] 检测所述功率开关上的电压谷值;以及 [0015] valley voltage of the power switch on the detector; and

[0016] 在持续一段延迟时间都未检测到所述谷值时,送出故障信号。 When [0016] the valley was not detected in a period of time delay, sending a fault signal.

[0017] 本发明的应用在半共振转换器一次侧的快速输出短路保护方法方法还可以采用以下的技术措施来进一步实现。 [0017] The present invention is applied in a rapid semi-resonant converter output side short-circuit protection methods may also be the following technical measures implemented to further use.

[0018] 前述的保护方法,其中所述延迟时间包括所述控制信号的数个周期。 [0018] The aforementioned protection methods, wherein said delay time comprises a number of cycles of the control signal.

[0019] 采用上述技术方案后,本发明的应用在半共振转换器一次侧的快速输出短路保护装置及方法具有在半共振转换器发生输出短路时能作出快速反应的优点。 [0019] With the above technical solution, the present invention is applied to a rapid output short circuit protection apparatus and method has the advantage that side reactions can be made quickly in the semi-resonant converter in output short semi-resonant converter. 附图说明 BRIEF DESCRIPTION

[0020] 图1为已知的半共振驰返式转换器示意图; [0020] Figure 1 is a known semi-resonant flyback converter schematic;

[0021] 图2为已知的输出短路保护电路图; [0021] FIG. 2 is a circuit diagram of a known output short circuit protection;

[0022] 图3为图1的半共振驰返式转换器操作在DCM时的波形图; [0022] FIG. 3 is a semi-resonant waveform chart Chi back converter when operating in DCM;

[0023] 图4为本发明的快速输出短路保护方法示意图; Fast output short circuit protection method of [0023] FIG. 4 is a schematic view of the invention;

[0024] 图5为本发明的快速输出短路保护装置示意图;以及 [0024] Fig 5 a schematic view of the rapid output short-circuit protection device of the present invention; and

[0025] 图6为图5的输出短路判断电路的操作示意图。 [0025] FIG. 6 is a schematic diagram illustrating the output short-circuit determination circuit 5 of FIG.

[0026] 图中,10、PWM控制器12、光耦合器14、比较器16、延迟电路20、电压Vds的波形22、 控制信号Vgs的波形24、电压Vaux的波形26、电流Ids的波形28、电流I_Do的波形30、输出电压Vo的波形32、磁感应电流I_Lm的波形34、电压Vds的波形36、波谷信号Sva的波形38、故障信号Fault的波形40、谷值检测器42、输出短路判断电路44、正反器46、正反器48、正反器50、正反器60、控制信号Vgs的波形62、反相输出端QNl上的信号的波形64、反相输出端QN2上的信号的波形66、反相输出端QN3上的信号的波形68、故障信号Fault的波形。 The waveform 24, the waveform 26 of the voltage Vaux, current Ids [0026] FIG, 10, PWM controller 12, optical coupler 14, comparator 16, delay circuit 20, the waveform 22 of the voltage Vds, Vgs of the control signal 28 waveform 30, the output voltage Vo of the waveform of the current I_Do 32, the magnetic induction current I_Lm waveform 34, the voltage Vds waveform 36, valley signal Sva waveform 38, waveform fault signal fault 40, valley detector 42, output short circuit is determined circuit 44, flip-flop 46, flip-flop 48, flip-flop 50, flip-flop 60, a control signal Vgs waveform 62, the waveform signal on the inverted output QNl 64, the inverted output signal QN2 waveform 66, the waveform signal on the inverted output QN3 68, the waveform of the fault signal fault. 具体实施方式 detailed description

[0027] 以下结合实施例及其附图对本发明作更进一步说明。 [0027] The following embodiments and the accompanying drawings in conjunction with embodiments of the present invention will be further described.

[0028] 现请参阅图3,图3为图1的半共振驰返式转换器操作在不连续电流模式(Discontinuous Current Mode ;DCM)的波形图。 [0028] Referring now to FIG. 3, FIG. 3 of FIG. 1 is a semi-resonant flyback converter operation (Discontinuous Current Mode; DCM) in the discontinuous current mode waveform of FIG. 如图所示,所述波形20为功率开关Sl上的电压Vds,波形22为控制信号Vgs,波形M为辅助线圈Laux上的电压Vaux,波形沈为通过功率开关Sl的电流Ids,波形观为通过二极管Do的电流I_Do。 As shown, the waveform 20 of the voltage on the power switch Sl Vds, Vgs of the control signal waveform 22, the voltage waveform M on the auxiliary winding Vaux Laux, Shen waveform through a current Ids of the power switch Sl, a waveform concept as current through the diode Do I_Do. 参照图1及图3,在时间tl至t2期间,如波形22所示,控制信号Vgs为高准位而打开(turn on)功率开关Si,因此功率开关Sl上的电压Vds为0,而通过开关Sl的电流Ids上升,如波形20及沈所示。 Referring to FIG. 1 and FIG. 3, time tl to time T2, as shown in waveform 22, the control signal Vgs is opened at a high level (turn on) the power switch Si, so that the voltage Vds on the power switch Sl is 0, and by increase current Ids switch Sl, as shown in waveform 20 and sink. 假设变压器Tl的一次侧线圈Lp、二次侧线圈Ls及辅助线圈Laux之间的匝数比为Np : Ns : Naux,可求得此期间辅助线圈Laux上的电压 Suppose the primary side coil of the transformer Tl Lp, between the number of turns of the secondary coil Ls and the auxiliary winding Laux ratio Np: Ns: Naux, can be obtained during the voltage on the auxiliary winding Laux

[0029] Vaux =-VinXNaux/Np 公式1 [0029] Vaux = -VinXNaux / Np Formula 1

[0030] 在时间t2时,控制信号Vgs转为低准位而关闭(turn off)功率开关Si,此时电流Ids变为0,而二次侧线圈Ls上产生电流I_Do通过二极管Do,同时辅助线圈Laux上的电压 [0030] At time t2, the control signal Vgs turns to the LOW level to close (turn off) the power switch Si, when the current Ids becomes 0, a current is generated through the diode Do I_Do to the secondary side coil Ls, while the auxiliary the voltage on the coil Laux

[0031] Vaux = (Vo+Vf) XNaux/Ns 公式2 [0031] Vaux = (Vo + Vf) XNaux / Ns Equation 2

[0032] 其中Vf为二极管Do的顺向偏压。 [0032] where Vf is the forward biased diode Do. 当电流I_Do下降至0时,如时间t3所示,功率开关1上的电压Vds将因激磁电感Lm及离散电容Ceq而产生弦波振荡,如波形20所示。 I_Do When the current drops to 0, as shown at time t3, the voltage Vds on the power switch 1 due to the magnetizing inductance Lm and capacitor Ceq discrete sine oscillation is generated, as shown in waveform 20.

[0033] 图4说明本发明的快速输出短路保护方法,其中波形30为输出电压Vo,波形32为磁感应电流I_Lm,波形34为电压Vds,波形36为波谷信号Sva,波形38为故障信号Fault。 [0033] Figure 4 illustrates a fast output short-circuit protection process of the present invention, wherein the waveform 30 is the output voltage Vo of, the waveform 32 of the magnetic induction current I_Lm, the waveform 34 of the voltage Vds of, waveform 36 is a valley signal Sva, waveform 38 is a fault signal Fault. 如前所述,当图1的半共振驰返式转换器在正常操作时,功率开关Sl上的电压Vds具有弦波振荡,因此可以检测电压Vds的谷值得到谷值信号&ιν,如波形36所示。 As described above, FIG. 1 when the semi-resonant flyback converter in normal operation, the voltage Vds has a power switch Sl sinusoidal oscillation, the voltage Vds can be detected valley to valley value signal worth & ιν, such as the waveform 36 Fig. 在时间t4时,半共振驰返式转换器的输出发生短路,故输出电压Vo变为0,如波形30所示。 At time t4, the semi-resonant flyback converter output short circuit, so the output voltage Vo becomes 0, as shown in the waveform 30. 由于变压器Tl 的重置电压 Since the reset voltage of the transformer Tl

[0034] Vro ^ Np/Ns X (Vo+Vf) 公式3 [0034] Vro ^ Np / Ns X (Vo + Vf) Equation 3

[0035] 因此当半共振驰返式转换器的输出发生短路时,重置电压Vro也将变的非常小, 几乎为0,这导致磁感应电流I_Lm无法重置为0,如波形32所示。 [0035] Thus, when the semi-resonant flyback converter output short circuit, the reset voltage Vro also becomes very small, almost zero, which causes the magnetic induction current I_Lm not reset to 0, the waveform 32 as shown. 也就是说,当半共振驰返式转换器发生输出短路时,半共振驰返式转换器将进入连续电流模式(Continuous Current Mode ;CCM)。 That is, when the semi-resonant flyback converter output short circuit occurs, the semi-resonant flyback converter enters a continuous current mode (Continuous Current Mode; CCM). 从图4的波形34可知,在半共振驰返式转换器发生输出短路后,功率开关Sl上的电压Vds不再产生弦波振荡,因此无法检测到电压Vds的谷值,利用此现象可以达成输出短路保护。 34 seen from the waveform of FIG. 4, in the semi-resonant flyback converter output short circuit occurs, the voltage Vds generated sine wave power switch Sl is no longer oscillate, and therefore can not detect the voltage Vds of the valley, this phenomenon can be achieved by using output short circuit protection. 如波形38所示,当持续一段延迟时间Tfault都未检测到电压Vds的谷值时,送出故障信号Fault以关闭PWM控制器10,延迟时间Tfault可以是控制信号Vgs 的数个周期。 As shown in waveform 38, a delay of time when the duration was not detected Tfault valley voltage Vds, sends a fault signal to turn off Fault PWM controller 10, the delay time may be a control signal Vgs Tfault several cycles.

[0036] 图5为本发明的快速输出短路保护装置,其包括谷值检测器40及输出短路判断电路42。 [0036] FIG. 5 fast output short circuit protection device of the present invention, which comprises a trough detector 40 and an output short-circuit determination circuit 42. 谷值检测器40检测功率开关Sl上电压Vds的谷值。 Valley detector 40 detects the power voltage Vds valley switch Sl. 检测电压Vds的谷值的方法有很多,在此实施例中藉由检测辅助线圈Laux上的电压Vaux来判断电压Vds的谷值,进而产生谷值信号Sva。 There are many ways of detecting voltage Vds valley, the valley embodiment by detecting the voltage on the auxiliary winding Vaux Laux voltage Vds is determined in this embodiment, thereby generating a valley signal Sva. 检测辅助线圈Laux上电压Vaux的谷值的技术已相当成熟,因此谷值检测器40的详细电路于此不再赘述。 Technical valley on the detection voltage of the auxiliary winding Vaux Laux is quite mature, so the detailed circuit valley detector 40 is omitted herein. 输出短路判断电路42利用控制信号Vgs来计算时间。 Output short circuit is determined by the control 42 calculates a time signal Vgs. 当持续数个控制信号Vgs周期的期间都未收到谷值信号Sva时,输出短路判断电路42认定半共振驰返式转换器发生输出短路,送出故障信号Fault去关闭PWM控制器10。 When the number of control signal duration period Vgs neither receive valley signal Sva, decision circuit 42 finds the output short semi-resonant flyback converter output short circuit occurs, sends a failure signal to turn off the PWM controller 10 Fault. 在此实施例中,输出短路判断电路42包括四个串联的正反器44、46、48及50。 In this embodiment, it comprises four serially connected flip-flop 42 outputs a short circuit determination circuit 44, 46 and 50. 第一级正反器44具有数据端D1、频率端clkl接收控制信号Vgs、清除端Cl接收谷值信号Sva、正相输出端Ql及反相输出端QNl连接数据端Dl。 The first stage flip-flop 44 having a data terminal D1, a clock terminal receiving a control signal clkl Vgs, Cl clear terminal receiving valley signal Sva, the positive-phase output terminal and the inverted output terminal Ql QNl connected data terminal Dl. 第二级正反器46具有数据端D2、频率端clk2连接前一级正反器44的反相输出端QN1、清除端C2接收谷值信号Sva、正相输出端Q2及反相输出端QN2 连接数据端D2。 The second stage flip-flop 46 having a data terminal D2, the front end of clk2 frequency QN1 connected to a inverting output terminal of flip-flop 44, a clear terminal C2 received signal Sva valley, the positive-phase output terminal and the inverted output terminal Q2 QN2 connecting the data terminal D2. 第三级正反器48具有数据端D3、频率端clk3连接前一级正反器46的反相输出端QN2、清除端C3接收谷值信号Sva、正相输出端Q3及反相输出端QN3连接数据端D3。 The third stage flip-flop 48 having a data terminal D3, clk3 front end connected to a frequency of the flip-flop inverted output QN2 46, the clear terminal C3 received signal Sva valley, the positive-phase output terminal and the inverted output terminal Q3 QN3 connecting the data terminal D3. 最后一级正反器50具有数据端D4、频率端clk4连接前一级正反器48的反相输出端QN3、清除端C4接收谷值信号Sva、正相输出端Q4及反相输出端QN4连接数据端D4。 Finally, a flip-flop 50 having a data terminal D4, the front end of the frequency clk4 QN3 connected to the inverting output terminal of a flip-flop 48, a clear terminal receiving valley signal Sva C4, the positive-phase output terminal and the inverted output terminal Q4 QN4 end connection data D4. [0037] 图6说明图5的输出短路判断电路42的操作,其中波形60为控制信号Vgsj^B 62为正反器44的反相输出端QNl上的信号,波形64为正反器46的反相输出端QN2上的信号,波形66为正反器48的反相输出端QN3上的信号,波形68为故障信号Fault。 [0037] FIG. 6 illustrates the output short circuit determination operation 42 5, wherein the control signal waveform 60 Vgsj ^ B 62 into a signal on the flip-flop inverted output QNl 44, the waveform 64 of the flip-flops 46 the inverted output signal QN2, the waveform signal on the flip-flop 66 is inverted output QN3 48, the waveform 68 of the fault signal fault. 参照图5 及图6,其中正反器44、46、48及50在初始状态下,正相输出端Q1、Q2、Q3及Q4的逻辑状态均为“0”,而反相输出端QN1、QN2、QN3及QN4的逻辑状态均为“1”。 Referring to FIG. 5 and FIG. 6 QN1, wherein the flip-flops 46, 48 and 50 in the initial state, the positive-phase output terminal Q1, Q2, Q3 and Q4 are both logic state "0", and the inverting output terminal, QN2, QN3 and QN4 are logical state "1." 假设在时间t 5时半共振驰返式转换器发生输出短路,谷值检测器40因而不再送出谷值信号Sva至清除端C1、C2、 C3及C4以重置正反器44、46、48及40。 Suppose at time t 5 when the semi-resonant flyback converter output short circuit occurs, the valley detector 40 is therefore not sent to the valley signal Sva clear terminal C1, C2, C3 and C4 to reset the flip-flop 44, 46, and 40. 在时间t5时,控制信号Vgs由低准位转为高准位, 如波形60所示,因此正反器44的反相输出端QNl上的逻辑状态由“1”变为“0”,如波形62 所示。 At time t5, the control signal Vgs from low level to a high level, as shown in waveform 60, thus the logic state of the flip-flop inverted output QNl 44 from "1" to "0", such as waveforms 62 shown in FIG. 在时间t6时,控制信号Vgs再次由低准位转为高准位,使得正反器44的反相输出端QNl上的逻辑状态由“0”变为“1”,因此正反器46的反相输出端QN2上的逻辑状态由“1” 变为“0”,如波形64所示。 At time T6, the control signal Vgs again from low level to a high level, so that the logic state of the flip-flop inverted output QNl 44 from "0" to "1", the flip-flop 46 logic state of the inverted output QN2 from "1" to "0", the waveform 64 as shown. 在时间t7时,正反器44的反相输出端QNl上的逻辑状态再次由“0”变为“1”,使得正反器46的反相输出端QN2上的逻辑状态由“0”变为” 1”,因此正反器48的反相输出端QN3上的逻辑状态由“1”变为“0”,如波形66所示。 At time T7, the logic state of the flip-flop inverted output QNl 44 again from "0" to "1", so that the logic state of the flip-flop inverted output QN2 46 by "0" is "1", so the logic state of the flip-flop inverted output QN3 48 from "1" to "0", the waveform as shown in FIG. 66. 在时间伪时,正反器46折反相输出端QN2上的逻辑状态再次由“0”变为“1”,使得正反器48的反相输出端QN3 上的逻辑状态由“0”变为“ 1 ”,因此故障信号Fault的逻辑状态由“0”变为“ 1 ”,如波形68 所示。 When the pseudo-time, the logic state of the flip-flop inverted output QN2 46 off again from "0" to "1", so that the logic state of the flip-flop inverted output QN3 48 by "0" is "1", the logic state of the fault fault signal from "0" to "1", the waveform 68 as shown.

[0038] 参照图6,在此实施例中,快速输出短路保护装置从半共振驰返式转换器发生输出短路至送出短路信号Fault的时间Tfault为控制信号Vgs的7个周期,大约只有100 μ s, 远小于已知的输出短路保护电路的反应时间(30ms以上),故本发明的输出短路保护装置在发生输出短路时可以更快速的反应,以避免在功率开关Sl上产生非常大的应力,而且当半共振驰返式转换器处于打嗝(hiccup)保护模式时也可以减少功率损失。 [0038] Referring to FIG 6, in this embodiment, the fast output short circuit protection device from a semi-resonant flyback converter output short to the transmission time of short-circuit signal Fault is Tfault seven cycle control signal Vgs is only about 100 μ s, the reaction time is much less than the known output short circuit protection circuit (30ms or more), so the output short-circuit protection device of the present invention can be more rapid response when the output short circuit occurs, to avoid very large stress on the power switch Sl and when the semi-resonant flyback converter is hiccup (hiccup) protected mode can also reduce the power loss. 输出短路判断电路42中的正反器数目可以依需求而增加或减少,进而改变时间Tfault的长短。 The number of flip-flop 42 output short circuit is determined on demand may be increased or decreased, thereby changing the length of time Tfault.

[0039] 以上实施例仅供说明本发明之用,而非对本发明的限制,有关技术领域的技术人员,在不脱离本发明的精神和范围的情况下,还可以作出各种变换或变化。 [0039] The above embodiments are merely illustrative of the present invention, not to limit the present invention, those skilled in the relevant art, without departing from the spirit and scope of the invention, also various modifications or variations may be made. 因此,所有等同的技术方案也应该属于本发明的范畴,应由各权利要求限定。 Therefore, all equivalent technical solutions should belong to the scope of the invention, the claims should be defined.

Claims (5)

1. 一种用于半共振转换器一次侧的快速输出短路保护装置,所述半共振转换器包含功率开关受一控制信号切换,其特征在于所述快速输出短路保护装置包括:谷值检测器连接所述功率开关,检测所述功率开关上的电压谷值而产生谷值信号;以及输出短路判断电路连接所述谷值检测器,当持续一段延迟时间都未接收到所述谷值信号时,送出故障信号。 A fast output short-circuit protection device on the primary side of the semi-resonant converter is used, the semi-resonant converter includes a power switch by a control signal, wherein said rapid output short-circuit protection device comprising: a valley detector connection of the power switch, the voltage detecting valley on the power switch signal generating valleys; and an output connected to said short-circuit judging circuit valley detector, when neither a delay duration to said receiving trough value signal , sends a fault signal.
2.如权利要求1所述的快速输出短路保护装置,其特征在于,所述延迟时间包括所述控制信号的数个周期。 2. The fast output short circuit protection device according to claim 1, wherein said delay time comprises a plurality of cycles of the control signal.
3.如权利要求1所述的快速输出短路保护装置,其特征在于,所述输出短路判断电路包括多个串接的正反器,每一所述正反器具有正相输出端、反相输出端、数据端连接所述反相输出端、清除端供接收所述谷值信号、以及频率端供接收所述控制信号或连接前一级正反器的反相输出端,所述故障信号由所述多个正反器中最后一级的正相输出端提供。 3. The fast output short circuit protection device according to claim 1, wherein said determination circuit comprises a plurality of short circuit output of flip-flops connected in series, each of said flip-flop having a positive-phase output terminal, an inverting an output terminal, a data terminal connected to the inverting output terminal, the fault clearing signal terminal for receiving said trough value signal, and a frequency control terminal for receiving said inverted signal or an output terminal of the flip-flop is connected to the front, provided by a plurality of the positive-phase output terminal of the flip-flop in the last stage.
4. 一种用于半共振转换器一次侧的快速输出短路保护方法,所述半共振转换器包含功率开关受一控制信号切换,其特征在于所述快速输出短路保护方法包括下列步骤:检测所述功率开关上的电压谷值;以及在持续一段延迟时间都未检测到所述谷值时,送出故障信号。 Fast output short circuit protection method for a semi-resonant converter on the primary side for a semi-resonant converter includes a power switch by a switching control signal, characterized in that said rapid output short circuit protection method comprising the steps of: detecting valley voltage on said power switch; and the valley was not detected in a period of time delay, sends the fault signal.
5.如权利要求4所述的快速输出短路保护方法,其特征在于,所述延迟时间包括所述控制信号的数个周期。 5. The fast output short circuit protection method as claimed in claim 4, wherein said delay time comprises a plurality of cycles of the control signal.
CN2009101979846A 2009-10-30 2009-10-30 Fast output short-circuit protection device and method used at primary side of semi-resonant converter CN102055175A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0919052A (en) * 1995-06-27 1997-01-17 Mitsubishi Electric Corp Protective device of converter
US20080232018A1 (en) * 2007-03-16 2008-09-25 Ta-Yung Yang Control Circuit with Short-circuit Protection for Current Sense Terminal of Power Converters
CN101282078A (en) * 2007-04-06 2008-10-08 电力集成公司 Method and apparatus for power converter fault condition detection
TW200915708A (en) * 2007-09-27 2009-04-01 Phison Electronics Corp Converter circuit with digital PWFM, method thereof and controller therewith

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0919052A (en) * 1995-06-27 1997-01-17 Mitsubishi Electric Corp Protective device of converter
US20080232018A1 (en) * 2007-03-16 2008-09-25 Ta-Yung Yang Control Circuit with Short-circuit Protection for Current Sense Terminal of Power Converters
CN101282078A (en) * 2007-04-06 2008-10-08 电力集成公司 Method and apparatus for power converter fault condition detection
TW200915708A (en) * 2007-09-27 2009-04-01 Phison Electronics Corp Converter circuit with digital PWFM, method thereof and controller therewith

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