TWI414118B - A power supply with a control circuit for a protective circuit - Google Patents
A power supply with a control circuit for a protective circuit Download PDFInfo
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本發明係有關於一電源供應器，特別是指一種電源供應器之具保護電路的控制電路。The present invention relates to a power supply, and more particularly to a control circuit having a protection circuit for a power supply.
隨著現今科技的進步，進而發展出許多電子產品，以因應民眾的需求，該些電子產品的功能越來越為強大，而帶給現今民眾在生活上許多便利。現今電子裝置大部分皆需要一電源供應器，以接收輸入電源，而提供適合電子裝置所需的電源。With the advancement of today's technology, many electronic products have been developed to meet the needs of the people, and the functions of these electronic products are becoming more and more powerful, bringing convenience to today's people. Most electronic devices today require a power supply to receive input power and provide the power needed for the electronic device.
請參閱第一圖，其為習用技術電源供應器的電路圖。如圖所示，習用之電源供應器包含一變壓器T1 ，其具有一一次側繞組NP 與一二次側繞組NS ，一次側繞組NP 之一端耦接一整流器10之輸出端，一次側繞組NP 之另一端耦接一功率開關Q1 ，功率開關Q1 透過一感測電阻RS 耦接於接地端，感測電阻RS 用於感測功率開關Q1 之一切換電流IP ，以產生一感測訊號VCS 。整流器10用於整流一輸入電源VAC ，整流器10之輸出端耦接一濾波電容Cbulk ，而用於對整流器10輸出之電源進行濾波，濾波電容Cbulk 上產生一整流電壓Vbulk 。變壓器T1 之二次側繞組NS 的一端耦接一整流器DO 之一端，一輸出電容CO 耦接於整流器DO 之另一端與二次側繞組NS 的另一端之間，輸出電容CO 亦耦接於電源供應器之輸出端，電源供應器之輸出端用於提供一輸出電壓VO 。Please refer to the first figure, which is a circuit diagram of a conventional power supply. As shown, the conventional power supply includes a transformer T 1 having a primary winding N P and a secondary winding N S , one end of the primary winding N P being coupled to the output of a rectifier 10, The other end of the primary winding N P is coupled to a power switch Q 1 . The power switch Q 1 is coupled to the ground through a sensing resistor R S , and the sensing resistor R S is used to sense a switching current of the power switch Q 1 . I P to generate a sensing signal V CS . A rectifier 10 for rectifying an AC input voltage V AC, the output of the rectifier 10 coupled to a filter capacitor C bulk, and power supply 10 for filtering the output of the rectifier generates a rectified voltage V bulk filter capacitor C bulk. One end of the secondary winding N S of the transformer T 1 is coupled to one end of a rectifier D O , and an output capacitor C O is coupled between the other end of the rectifier D O and the other end of the secondary winding N S , the output capacitor C O is also coupled to the output of the power supply, and the output of the power supply is used to provide an output voltage V O .
復參閱第一圖，習用之電源供應器的控制電路，其包含一正反器20以用於產生一切換訊號VPWM ，而控制電源供應器之功率開關Q1 ，正反器20之一時脈輸入端CK耦接至一振盪器22，以接收振盪器22所產生之一脈波訊號PLS，正反器20之一輸入端D耦接至一供應電壓VCC ，正反器20之一輸出端Q則產生切換訊號VPWM ，以控制電源供應器之功率開關Q1 。電 源供應器之控制電路更包含一分壓電路，其包含兩電阻RA 與RB ，電阻RA 耦接至整流器10之輸出端，電阻RB 耦接於電阻RA 與接地端之間，一濾波電容CF 並聯於電阻RB ，以用於進行濾波，而產生一輸入電壓VIN 。Referring to the first figure, the control circuit of the conventional power supply includes a flip-flop 20 for generating a switching signal V PWM , and controlling the power switch Q 1 of the power supply, and the clock of the flip-flop 20 The input terminal CK is coupled to an oscillator 22 for receiving a pulse signal PLS generated by the oscillator 22. One input terminal D of the flip-flop 20 is coupled to a supply voltage V CC , and one of the flip-flops 20 outputs The terminal Q generates a switching signal V PWM to control the power switch Q 1 of the power supply. The control circuit of the power supply further includes a voltage dividing circuit including two resistors R A and R B , the resistor R A is coupled to the output end of the rectifier 10 , and the resistor R B is coupled between the resistor R A and the ground terminal A filter capacitor C F is connected in parallel to the resistor R B for filtering to generate an input voltage V IN .
復參閱第一圖，一比較器31之正輸入端接收一臨界訊號VM ，負輸入端則耦接至感測電阻RS 而接收感測訊號VCS ，以比較臨界訊號VM 與感測訊號VCS 。一比較器32之正輸入端接收輸入電壓VIN ，而比較器22之負輸入端則耦接一參考電壓VREF ，以比較輸入電壓VIN 與參考電壓VREF 。一及閘33接收比較器31與比較器32之輸出，以產生一重置訊號RST，而用於截止切換訊號VPWM ，以保護電源供應器。Referring to the first figure, a positive input terminal of a comparator 31 receives a threshold signal V M , and a negative input terminal is coupled to the sensing resistor R S to receive the sensing signal V CS to compare the threshold signal V M with the sensing. Signal V CS . The positive input of a comparator 32 receives the input voltage V IN , and the negative input of the comparator 22 is coupled to a reference voltage V REF to compare the input voltage V IN with the reference voltage V REF . The AND gate 33 receives the output of the comparator 31 and the comparator 32 to generate a reset signal RST for turning off the switching signal V PWM to protect the power supply.
請參閱第二圖，其為電源供應器之濾波電容Cbulk 與CF 之整流電壓Vbulk 與輸入電壓VIN 的波形圖。整流電壓Vbulk 透過電阻RA 與RB 所組成的分壓電路進行降壓，濾波電容CF 是用於對降壓後之整流電壓Vbulk 進行濾波，以產生輸入電壓VIN ，而提供至比較器32。如第二圖所示，濾波電容CF 對經過降壓之整流電壓Vbulk 濾波後所得的輸入電壓VIN ，其仍會有漣波，此漣波會導致比較器32無法精確比較輸入電壓VIN 與參考電壓VREF ，而無法確實控制切換訊號VPWM ，即無法對電源供應器作精確的保護，如此會降低電源供應器之效能。Please refer to the second figure, which is a waveform diagram of the rectified voltage V bulk and the input voltage V IN of the filter capacitors C bulk and C F of the power supply. The rectified voltage V bulk is stepped down by a voltage dividing circuit composed of resistors R A and R B , and the filter capacitor C F is used for filtering the stepped rectified voltage V bulk to generate an input voltage V IN To comparator 32. As shown in the second figure, the filter capacitor C F will still chop the input voltage V IN after the step-down rectified voltage V bulk is filtered. This chopping will cause the comparator 32 to accurately compare the input voltage V. IN and the reference voltage V REF , and can not really control the switching signal V PWM , that is, the power supply can not be precisely protected, which will reduce the performance of the power supply.
因此，本發明即針對上述問題而提出一種電源供應器之具保護電路的控制電路，其可確實依據輸入電源之波峰，而精確控制切換訊號，進而確實保護電源供應器，以解決上述問題。Therefore, the present invention is directed to the above problem, and provides a control circuit for a power supply device with a protection circuit that can accurately control the switching signal according to the peak of the input power source, thereby reliably protecting the power supply to solve the above problem.
本發明之目的，在於提供一種電源供應器之具保護電路的控制電路，其藉由波峰偵測電路偵測輸入電源之波峰，以達確實保護電源供應器的目的。It is an object of the present invention to provide a control circuit for a power supply device with a protection circuit that detects a peak of an input power source by a peak detection circuit to achieve a purpose of protecting the power supply.
本發明電源供應器之具保護電路的控制電路，其包含有一波峰偵測電 路與一保護電路，波峰偵測電路用於偵測一輸入電源而產生一波峰偵測訊號，保護電路用於依據波峰偵測訊號產生一重置訊號，以截止電源供應器之輸出。此外，本發明之控制電路更包含一取樣保持電路，其取樣波峰偵測訊號，並產生一保持訊號，保護電路更進一步依據保持訊號產生重置訊號，以截止電源供應器之輸出。控制電路更包含一切換電路，切換電路依據一脈波訊號產生一切換訊號，以控制電源供應器之一功率開關，以控制電源供應器之輸出。A control circuit for a protection circuit of the power supply of the present invention, comprising a peak detection The circuit and a protection circuit, the peak detection circuit is configured to detect an input power source to generate a peak detection signal, and the protection circuit is configured to generate a reset signal according to the peak detection signal to cut off the output of the power supply. In addition, the control circuit of the present invention further includes a sample and hold circuit that samples the peak detection signal and generates a hold signal, and the protection circuit further generates a reset signal according to the hold signal to cut off the output of the power supply. The control circuit further includes a switching circuit that generates a switching signal according to a pulse signal to control a power switch of the power supply to control the output of the power supply.
茲為使 貴審查委員對本發明之技術特徵及所達成之功效更有進一步之瞭解與認識，謹佐以較佳之實施例圖及配合詳細之說明，說明如後：請參閱第三圖，其為本發明之一較佳實施例之電源供應器的電路圖。如圖所示，電源供應器包含一變壓器T1 ，變壓器T1 從一次側轉移能量至二次側，以提供經調整之一輸出電壓VO 。變壓器T1 之一次側與二次側分別具有一一次側繞組NP 與一二次側繞組NS ，一次側繞組NP 之一端耦接一整流器40，一次側繞組NP 之另一端耦接一功率開關Q1 ，功率開關Q1 串聯一感測元件，感測元件於本實施例中為一感測電阻RS ，功率開關Q1 之一端耦接感測電阻RS 之一端，感測電阻RS 之另一端耦接於接地端，感測電阻RS 用於感測功率開關Q1 之一切換電流IP ，而產生一感測訊號VCS 。上述之功率開關Q1 用於控制變壓器T1 ，以控制電源供應器之輸出VO ，其一較佳實施例可為一電晶體。For a better understanding and understanding of the technical features and the achievable effects of the present invention, please refer to the preferred embodiment and the detailed description, as explained below: please refer to the third figure, which is A circuit diagram of a power supply of a preferred embodiment of the present invention. As shown, the power supply comprises a transformer T 1, T 1 of the transformer to transfer energy from the primary side to the secondary side, one to provide an adjusted output voltage V O. The primary side and the secondary side of the transformer T 1 respectively have a primary side winding N P and a secondary side winding N S , one end of the primary side winding N P is coupled to a rectifier 40 , and the other end of the primary side winding N P is coupled Connected to a power switch Q 1 , the power switch Q 1 is connected in series with a sensing component. In this embodiment, the sensing component is a sensing resistor R S , and one end of the power switch Q 1 is coupled to one end of the sensing resistor R S . The other end of the measuring resistor R S is coupled to the ground, and the sensing resistor R S is used to sense the switching current I P of the power switch Q 1 to generate a sensing signal V CS . The power switch Q 1 described above is used to control the transformer T 1 to control the output V O of the power supply. A preferred embodiment thereof may be a transistor.
承接上述，整流器40接收一輸入電源VAC ，並整流輸入電源VAC ，整流器40之輸出端更耦接一濾波電容Cbulk ，以對整流器40整流後之電壓進行濾波，以產生一整流電壓Vbulk 。變壓器T1 之二次側繞組NS 的一端耦接一整流器DO 之一端，整流器DO 之另一端與二次側繞組NS 的另一端之間耦 接一輸出電容CO ，輸出電容CO 亦耦接於電源供應器之輸出端，電源供應器之輸出端用於提供輸出電壓VO 。In response to the above, the rectifier 40 receives an input power V AC and rectifies the input power V AC . The output of the rectifier 40 is further coupled to a filter capacitor C bulk to filter the voltage rectified by the rectifier 40 to generate a rectified voltage V. Bulk . One end of the secondary winding N S of the transformer T 1 is coupled to one end of a rectifier D O , and the other end of the rectifier D O and the other end of the secondary winding N S are coupled to an output capacitor C O , and the output capacitor C O is also coupled to the output of the power supply, and the output of the power supply is used to provide an output voltage V O .
復參閱第三圖，本發明之控制電路包含有一切換電路，而用於產生一切換訊號VPWM 而控制功率開關Q1 ，進而控制變壓器T1 ，以控制電源供應器之輸出電壓VO 。本發明之切換電路包含有一正反器48與一振盪器49，振盪器49用於產生一脈波訊號PLS。正反器48之一輸入端D接收一供應電壓VCC ，正反器48之一時脈輸入端CK接收脈波訊號PLS，正反器48之一輸出端Q輸出該切換訊號VPWM ，以控制電源供應器之功率開關Q1 ，而控制電源供應器之輸出VO 。Referring to the third figure, the control circuit of the present invention includes a switching circuit for generating a switching signal V PWM to control the power switch Q 1 , thereby controlling the transformer T 1 to control the output voltage V O of the power supply. The switching circuit of the present invention includes a flip-flop 48 and an oscillator 49 for generating a pulse signal PLS. One input terminal D of the flip-flop 48 receives a supply voltage V CC , and one clock input terminal CK of the flip-flop 48 receives the pulse signal PLS, and one output terminal Q of the flip-flop 48 outputs the switching signal V PWM to control The power supply's power switch Q 1 controls the power supply's output V O .
復參閱第三圖，本發明之控制電路更包含一二極體42，其耦接於整流器40之輸出端。一電阻44耦接於二極體42與一取樣開關46之間，一偵測元件耦接於取樣開關46與接地端之間，其一實施例可為一電阻47。取樣開關46接收一半波電壓Vhv ，其相關於輸入電源VAC ，取樣開關46受控於一取樣控制訊號SP ，透過二極體42的整流作用，對半個電源週期的輸入電源VAC 進行取樣而產生一取樣電流，電阻47偵測取樣電流而產生一取樣訊號Vsample 。取樣開關46之一實施例可為一電晶體。上述之取樣控制訊號SP 係為一固定週期內具有週期性地導通與截止的切換動作，其波形請參考第四圖所示，其電路產生方式甚多，其一實施例可為電源供應器之內部電路所產生，其為一般常用之技術，於此不再詳述。Referring to the third figure, the control circuit of the present invention further includes a diode 42 coupled to the output of the rectifier 40. A resistor 44 is coupled between the diode 42 and a sampling switch 46. A detecting component is coupled between the sampling switch 46 and the ground. One embodiment of the resistor is a resistor 47. The sampling switch 46 receives the half-wave voltage V hv , which is related to the input power source V AC , and the sampling switch 46 is controlled by a sampling control signal S P , through the rectification of the diode 42 , the input power source V AC for half of the power cycle. A sampling current is generated to generate a sampling current, and the resistor 47 detects the sampling current to generate a sampling signal V sample . One embodiment of the sampling switch 46 can be a transistor. The sampling control signal S P is a switching operation that is periodically turned on and off in a fixed period, and the waveform thereof is shown in the fourth figure. The circuit is generated in many ways, and an embodiment thereof may be a power supply. It is generated by the internal circuit, which is a commonly used technology and will not be described in detail herein.
復參閱第三圖，本發明之控制電路更包含一波峰偵測電路50、一取樣保持電路60與一保護電路70，取樣保持電路60耦接於波峰偵測電路50與保護電路70之間。波峰偵測電路50偵測取樣訊號Vsample 產生波峰偵測訊號Vpeak ，取樣保持電路60取樣波峰偵測訊號Vpeak ，並產生一保持訊號Vhold 。由於取樣訊號Vsample 相關於輸入電源VAC ，所以波峰偵測電路50即相當用 於偵測輸入電源VAC 之波峰，而產生波峰偵測訊號Vpeak 。保護電路70用於產生一重置訊號RST，在輸入電源VAC 過低或切換電流IP 過高時，而截止切換訊號VPWM ，以保護電源供應器。Referring to the third embodiment, the control circuit of the present invention further includes a peak detecting circuit 50, a sample and hold circuit 60 and a protection circuit 70. The sample and hold circuit 60 is coupled between the peak detecting circuit 50 and the protection circuit 70. The peak detecting circuit 50 detects the sampling signal V sample to generate a peak detecting signal V peak , and the sample holding circuit 60 samples the peak detecting signal V peak and generates a holding signal V hold . Since the sampling signal V sample is related to the input power source V AC , the peak detecting circuit 50 is equivalent to detecting the peak of the input power source V AC to generate the peak detecting signal V peak . The protection circuit 70 is configured to generate a reset signal RST to turn off the switching signal V PWM when the input power source V AC is too low or the switching current I P is too high to protect the power supply.
承接上述，保護電路70包含有一比較器71、一磁滯比較器72與一邏輯閘73，比較器71與磁滯比較器72分別作為一過電流保護電路與一低電壓保護電路，而邏輯閘73為一及閘。比較器71之正輸入端接收保持訊號Vhold ，負輸入端接收感測訊號VCS ，感測訊號VCS 相關於切換電流IP ，比較器71比較保持訊號Vhold 與感測訊號VCS ，當感測訊號VCS 超過保持訊號Vhold 時，用以輸出一過電流保護訊號。磁滯比較器72之正輸入端接收波峰偵測訊號Vpeak ，負輸入端接收一參考電壓VREF ，磁滯比較器72比較波峰偵測訊號Vpeak 與參考電壓VREF ，當波峰偵測訊號Vpeak 低於參考電壓VREF 時，用以產生一低電壓保護訊號。邏輯閘73接收過電流保護訊號與低電壓保護訊號產生一重置訊號RST，以截止切換訊號VPWM ，而關閉電源供應器。邏輯閘73於接收低準位之過電流保護訊號或低電壓保護訊號時，即會產生重置訊號RST而截止切換訊號VPWM ，也就表示比較器71與磁滯比較器72之過電流保護訊號與低電壓保護訊號，係用於截止電源供應器之輸出，以保護電源供應器。In the above, the protection circuit 70 includes a comparator 71, a hysteresis comparator 72 and a logic gate 73, and the comparator 71 and the hysteresis comparator 72 respectively serve as an overcurrent protection circuit and a low voltage protection circuit, and the logic gate 73 is a gate. The positive input terminal of the comparator 71 receives the hold signal Vhold , the negative input terminal receives the sensing signal V CS , the sensing signal V CS is related to the switching current I P , and the comparator 71 compares the hold signal V hold with the sensing signal V CS . When the sensing signal V CS exceeds the hold signal Vhold , an overcurrent protection signal is output. The positive input terminal of the hysteresis comparator 72 receives the peak detection signal Vpeak , the negative input terminal receives a reference voltage V REF , and the hysteresis comparator 72 compares the peak detection signal V peak with the reference voltage V REF when the peak detection signal When V peak is lower than the reference voltage V REF , it is used to generate a low voltage protection signal. The logic gate 73 receives the overcurrent protection signal and the low voltage protection signal to generate a reset signal RST to turn off the switching signal VPWM and turn off the power supply. When the logic gate 73 receives the low level protection signal or the low voltage protection signal of the low level, the reset signal RST is generated and the switching signal V PWM is turned off, which means that the comparator 71 and the hysteresis comparator 72 are overcurrent protected. Signal and low voltage protection signals are used to cut off the output of the power supply to protect the power supply.
請參閱第四圖，其為本發明之一較佳實施例之電源供應器之波形圖。如圖所示，輸入電源VAC 經過二極體42(參閱第三圖)整流後則產生半波電壓Vhv ，且依據取樣控制訊號SP 取樣半波電壓Vhv 而產生取樣訊號Vsample ，其中取樣控制訊號SP 係為一固定週期內具有週期性地導通與截止的切換動作。波峰偵測電路50(參閱第三圖)偵測取樣訊號Vsample ，以產生波峰偵測訊號Vpeak ，由圖示可知，波峰偵測訊號Vpeak 並沒有漣波情形，所以磁滯比較器72可精確比較波峰偵測訊號Vpeak 與參考電壓VREF ，以確實保護電源供應器，而提升電源供應器之效能。此外，取樣保持電路60(參閱第三 圖)依據控制訊號Vph1 與Vph2 取樣峰偵測訊號Vpe ak，以產生保持訊號Vhold ，保持訊號Vhold 並未有漣波情形，所以比較器71可精確比較保持訊號Vhold 與感測訊號VCS ，以確實保護電源供應器。Please refer to the fourth figure, which is a waveform diagram of a power supply according to a preferred embodiment of the present invention. As shown, the input V AC power through the diode 42 (see FIG third) is generated after a half-wave rectified voltage V hv, and based on the sampling control signal S P sampling half-wave voltage V hv generated sample signal V sample, The sampling control signal S P is a switching operation with periodic conduction and cutoff in a fixed period. The peak detecting circuit 50 (refer to the third figure) detects the sampling signal V sample to generate the peak detecting signal V peak . As shown in the figure, the peak detecting signal V peak has no chopping condition, so the hysteresis comparator 72 The peak detection signal V peak and the reference voltage V REF can be accurately compared to surely protect the power supply and improve the performance of the power supply. In addition, the sample and hold circuit 60 (refer to the third figure) samples the peak detection signal V pe ak according to the control signals V ph1 and V ph2 to generate the hold signal V hold , and keeps the signal V hold without chopping, so the comparator 71 can accurately compare the hold signal V hold with the sense signal V CS to reliably protect the power supply.
請參閱第五圖，其為本發明之一較佳實施例之波峰偵測電路的電路圖。如圖所示，波峰偵測電路50包含一二極體52、一放電開關54、一電容Cch 與一緩衝器56。二極體52之正極接收取樣訊號Vsample ，電容Cch 耦接於二極體52之負極與接地之間，取樣訊號Vsample 對電容Cch 充電。放電開關54耦接於電容Cch 與接地端之間，以對電容Cch 放電，放電開關54受控於重置訊號VRST ，重置訊號VRST 產生方式甚多，其一實施例可為電源供應器之內部電路所產生，其為一般常用之技術，於此不再詳述。緩衝器56之輸入端耦接電容Cch ，緩衝器56輸出波峰偵測訊號Vpeak 。Please refer to FIG. 5, which is a circuit diagram of a peak detecting circuit according to a preferred embodiment of the present invention. As shown, the peak detecting circuit 50 includes a diode 52, a discharge switch 54, a capacitor Cch and a buffer 56. The positive pole of the diode 52 receives the sampling signal V sample , the capacitor C ch is coupled between the cathode of the diode 52 and the ground, and the sampling signal V sample charges the capacitor C ch . The discharge switch 54 is coupled between the capacitor C ch and the ground to discharge the capacitor C ch , the discharge switch 54 is controlled by the reset signal V RST , and the reset signal V RST is generated in a plurality of manners. The internal circuit of the power supply is generated, which is a commonly used technology, and will not be described in detail herein. The input end of the buffer 56 is coupled to the capacitor C ch , and the buffer 56 outputs a peak detection signal V peak .
請參閱第六圖，其為本發明之一較佳實施例之取樣保持電路的電路圖。如圖所示，取樣保持電路60接收波峰偵測訊號Vpeak ，以取樣波峰偵測訊號Vpeak 並產生保持訊號Vhold 。取樣保持電路60包含開關62、64與65、一電容63與一比較器66。開關62耦接於波峰偵測電路50(參閱第三圖)之輸出端，以接收波峰偵測訊號Vpeak ，開關62之另一端耦接於電容63之第一端，電容63之第二端耦接於比較器66之負輸入端，比較器66之正輸入端耦接於接地端，比較器66之輸出端產生保持訊號Vhold 。開關64耦接於比較器66之負輸入端與輸出端之間，開關62、64受控於控制訊號Vph1 。開關65耦接於電容63之第一端與比較器66的輸出端之間，開關65受控於控制訊號Vph2 。控制訊號Vph1 、Vph2 產生方式甚多，兩者互為上下相反的控制訊號，並且在上升與下降期間保持一短路防止時間，避免控制訊號Vph1 、Vph2 有同時導通的情形，其波形請參考第四圖所示。其一實施例可為電源供應器之內部電路所產生，其為一般常用之技術，於此不再詳述。Please refer to a sixth diagram, which is a circuit diagram of a sample and hold circuit in accordance with a preferred embodiment of the present invention. As shown, the sample and hold circuit 60 receives the peak detection signal Vpeak to sample the peak detection signal Vpeak and generate a hold signal Vhold . The sample and hold circuit 60 includes switches 62, 64 and 65, a capacitor 63 and a comparator 66. The switch 62 is coupled to the output of the peak detecting circuit 50 (see FIG. 3) to receive the peak detecting signal Vpeak . The other end of the switch 62 is coupled to the first end of the capacitor 63, and the second end of the capacitor 63. The positive input terminal of the comparator 66 is coupled to the ground terminal, and the output of the comparator 66 generates a hold signal Vhold . The switch 64 is coupled between the negative input terminal and the output terminal of the comparator 66, and the switches 62, 64 are controlled by the control signal V ph1 . The switch 65 is coupled between the first end of the capacitor 63 and the output of the comparator 66, and the switch 65 is controlled by the control signal V ph2 . The control signals V ph1 and V ph2 are generated in a large number of ways, and the two are mutually opposite control signals, and a short circuit prevention time is maintained during the rising and falling periods, and the control signals V ph1 and V ph2 are simultaneously turned on, and the waveforms thereof are prevented. Please refer to the fourth picture. An embodiment of the present invention can be generated by an internal circuit of a power supply, which is a commonly used technology and will not be described in detail herein.
綜上所述，本發明電源供應器的控制電路，其包含有波峰偵測電路、取樣保持電路與保護電路，波峰偵測電路偵測輸入電源產生波峰偵測訊號，取樣保持電路取樣波峰偵測訊號並產生保持訊號，保護電路依據波峰偵測訊號或保持訊號產生重置訊號，以截止電源供應器之輸出。本發明的控制電路藉由波峰偵測電路偵測輸入電源的波峰，以確實依據輸入電源而控制切換訊號，而達到精確保護電源供應器的目的。In summary, the control circuit of the power supply of the present invention comprises a peak detecting circuit, a sample holding circuit and a protection circuit, the peak detecting circuit detects the input power to generate a peak detecting signal, and the sampling and holding circuit samples the peak detecting. The signal generates a hold signal, and the protection circuit generates a reset signal according to the peak detection signal or the hold signal to cut off the output of the power supply. The control circuit of the present invention detects the peak of the input power source by the peak detecting circuit to control the switching signal according to the input power source, thereby achieving the purpose of accurately protecting the power supply.
故本發明實為一具有新穎性、進步性及可供產業上利用者，應符合我國專利法專利申請要件無疑，爰依法提出發明專利申請，祈 鈞局早日賜准專利，至感為禱。Therefore, the present invention is a novelty, progressive and available for industrial use. It should be in accordance with the requirements of patent applications for patent law in China. It is undoubtedly to file an invention patent application according to law, and the Prayer Council will grant patents as soon as possible.
惟以上所述者，僅為本發明一較佳實施例而已，並非用來限定本發明實施之範圍，故舉凡依本發明申請專利範圍所述之形狀、構造、特徵及精神所為之均等變化與修飾，均應包括於本發明之申請專利範圍內。However, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, so that the shapes, structures, features, and spirits described in the claims of the present invention are equally changed. Modifications are intended to be included in the scope of the patent application of the present invention.
10‧‧‧整流器10‧‧‧Rectifier
20‧‧‧正反器20‧‧‧Fracture
22‧‧‧振盪器22‧‧‧Oscillator
31‧‧‧比較器31‧‧‧ Comparator
32‧‧‧比較器32‧‧‧ comparator
33‧‧‧及閘33‧‧‧ and gate
40‧‧‧整流器40‧‧‧Rectifier
42‧‧‧二極體42‧‧‧ diode
44‧‧‧電阻44‧‧‧resistance
46‧‧‧取樣開關46‧‧‧Sampling switch
47‧‧‧電阻47‧‧‧resistance
48‧‧‧正反器48‧‧‧Fracture
49‧‧‧震盪器49‧‧‧ oscillator
50‧‧‧波峰偵測電路50‧‧‧Crest detection circuit
52‧‧‧二極體52‧‧‧ diode
54‧‧‧放電開關54‧‧‧Discharge switch
55‧‧‧震盪器55‧‧‧ oscillator
56‧‧‧緩衝器56‧‧‧ buffer
60‧‧‧取樣保持電路60‧‧‧Sampling and holding circuit
62‧‧‧開關62‧‧‧ switch
63‧‧‧電容63‧‧‧ Capacitance
64‧‧‧開關64‧‧‧ switch
65‧‧‧開關65‧‧‧ switch
66‧‧‧比較器66‧‧‧ comparator
70‧‧‧保護電路70‧‧‧Protection circuit
71‧‧‧比較器71‧‧‧ Comparator
72‧‧‧磁滯比較器72‧‧‧Magnetic hysteresis comparator
73‧‧‧邏輯閘73‧‧‧Logic gate
IP ‧‧‧切換電流I P ‧‧‧Switching current
NP ‧‧‧一次側繞組N P ‧‧‧ primary winding
NS ‧‧‧二次側繞組N S ‧‧‧secondary winding
CF ‧‧‧濾波電容C F ‧‧‧Filter Capacitor
CO ‧‧‧輸出電容C O ‧‧‧ output capacitor
Cch ‧‧‧電容C ch ‧‧‧ capacitor
Cbulk ‧‧‧濾波電容C bulk ‧‧‧Filter capacitor
DO ‧‧‧整流器D O ‧‧‧Rectifier
PLS‧‧‧脈波訊號PLS‧‧‧ pulse signal
Q1 ‧‧‧功率開關Q 1 ‧‧‧Power switch
RA ‧‧‧電阻R A ‧‧‧resistance
RB ‧‧‧電阻R B ‧‧‧resistance
RS ‧‧‧感測電阻R S ‧‧‧resistance resistor
RST‧‧‧重置訊號RST‧‧‧Reset signal
SP ‧‧‧取樣控制訊號S P ‧‧‧Sampling control signal
T1 ‧‧‧變壓器T 1 ‧‧‧Transformer
VO ‧‧‧輸出電壓V O ‧‧‧Output voltage
VAC ‧‧‧輸入電源V AC ‧‧‧Input power supply
Vbulk ‧‧‧整流電壓V bulk ‧ ‧ rectified voltage
VCC ‧‧‧供應電壓V CC ‧‧‧ supply voltage
VCS ‧‧‧感測訊號V CS ‧‧‧Sensior signal
VM ‧‧‧臨界訊號V M ‧‧‧critical signal
Vhv ‧‧‧半波電壓V hv ‧‧‧ half-wave voltage
Vhold ‧‧‧保持訊號V hold ‧‧‧keeping signal
VIN ‧‧‧輸入電壓V IN ‧‧‧ input voltage
Vph1 ‧‧‧控制訊號V ph1 ‧‧‧ control signal
Vph2 ‧‧‧控制訊號V ph2 ‧‧‧ control signal
VPWM ‧‧‧切換訊號V PWM ‧‧‧Switching signal
Vpeak ‧‧‧波峰偵測訊號V peak ‧‧‧peak detection signal
VREF ‧‧‧參考電壓V REF ‧‧‧reference voltage
Vsample ‧‧‧取樣訊號V sample ‧‧‧Sampling signal
第一圖係習用之電源供應器的電路圖；第二圖係習用之電源供應器的波形圖；第三圖係本發明之一較佳實施例之電源供應器的電路圖；第四圖係本發明之一較佳實施例之電源供應器的波形圖；第五圖係本發明之一較佳實施例之波峰偵測電路的電路圖；以及第六圖係本發明之一較佳實施例之取樣保持電路的電路圖。The first drawing is a circuit diagram of a conventional power supply; the second drawing is a waveform diagram of a conventional power supply; the third drawing is a circuit diagram of a power supply according to a preferred embodiment of the present invention; and the fourth drawing is the present invention. A waveform diagram of a power supply of a preferred embodiment; a fifth diagram is a circuit diagram of a peak detection circuit of a preferred embodiment of the present invention; and a sixth diagram is a sample retention of a preferred embodiment of the present invention. Circuit diagram of the circuit.
40‧‧‧整流器40‧‧‧Rectifier
42‧‧‧二極體42‧‧‧ diode
44‧‧‧電阻44‧‧‧resistance
46‧‧‧取樣開關46‧‧‧Sampling switch
47‧‧‧電阻47‧‧‧resistance
48‧‧‧正反器48‧‧‧Fracture
49‧‧‧震盪器49‧‧‧ oscillator
50‧‧‧波峰偵測電路50‧‧‧Crest detection circuit
55‧‧‧震盪器55‧‧‧ oscillator
60‧‧‧取樣保持電路60‧‧‧Sampling and holding circuit
70‧‧‧保護電路70‧‧‧Protection circuit
71‧‧‧比較器71‧‧‧ Comparator
72‧‧‧磁滯比較器72‧‧‧Magnetic hysteresis comparator
73‧‧‧邏輯閘73‧‧‧Logic gate
IP ‧‧‧切換電流I P ‧‧‧Switching current
NP ‧‧‧一次側繞組N P ‧‧‧ primary winding
NS ‧‧‧二次側繞組N S ‧‧‧secondary winding
CO ‧‧‧輸出電容C O ‧‧‧ output capacitor
Cbulk ‧‧‧濾波電容C bulk ‧‧‧Filter capacitor
DO ‧‧‧整流器D O ‧‧‧Rectifier
PLS‧‧‧脈波訊號PLS‧‧‧ pulse signal
Q1 ‧‧‧功率開關Q 1 ‧‧‧Power switch
RS ‧‧‧感測電阻R S ‧‧‧resistance resistor
RST‧‧‧重置訊號RST‧‧‧Reset signal
SP ‧‧‧取樣控制訊號S P ‧‧‧Sampling control signal
T1 ‧‧‧變壓器T 1 ‧‧‧Transformer
VO ‧‧‧輸出電壓V O ‧‧‧Output voltage
VAC ‧‧‧輸入電源V AC ‧‧‧Input power supply
Vbulk ‧‧‧整流電壓V bulk ‧ ‧ rectified voltage
VCC ‧‧‧供應電壓V CC ‧‧‧ supply voltage
VCS ‧‧‧感測訊號V CS ‧‧‧Sensior signal
Vhv ‧‧‧半波電壓V hv ‧‧‧ half-wave voltage
Vhold ‧‧‧保持訊號V hold ‧‧‧keeping signal
VPWM ‧‧‧切換訊號V PWM ‧‧‧Switching signal
Vpeak ‧‧‧波峰偵測訊號V peak ‧‧‧peak detection signal
VREF ‧‧‧參考電壓V REF ‧‧‧reference voltage
Vsample ‧‧‧取樣訊號V sample ‧‧‧Sampling signal
Claims (6)
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| TWM327600U (en) * | 2007-06-13 | 2008-02-21 | Niko Semiconductor Co Ltd | The output current limited control for switching power supply and controller for controlling the same |
-
2008
- 2008-11-11 TW TW97143517A patent/TWI414118B/en active
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| US4432031A (en) * | 1982-05-03 | 1984-02-14 | General Electric Company | Method for overcurrent protection |
| US5754250A (en) * | 1992-02-18 | 1998-05-19 | Cooper; J. Carl | Synchronizing signal separating apparatus and method |
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| US20060106502A1 (en) * | 2001-07-26 | 2006-05-18 | Thales North America, Inc. | Apparatus, method and computer program product for monitoring AC line current through the step start resistors of a high voltage power supply |
| US20060056204A1 (en) * | 2004-09-16 | 2006-03-16 | Ta-Yung Yang | Switching control circuit for primary-side controlled power converters |
| TWI276297B (en) * | 2005-08-26 | 2007-03-11 | Topower Computer Ind Co Ltd | A power supply equipped with an independent overload protection mechanism |
| TWM327600U (en) * | 2007-06-13 | 2008-02-21 | Niko Semiconductor Co Ltd | The output current limited control for switching power supply and controller for controlling the same |
Also Published As
| Publication number | Publication date |
|---|---|
| TW201019559A (en) | 2010-05-16 |
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