TWM312119U - Exchange-type power supply with feedback-control on the primary side - Google Patents

Description

M312119 VIII. New description: [New technical field] Second: The system is related to the -sub-secondary feedback control, especially when the output reaches the current limit, the wheel can control the material change, and the money goes out = power out ~ Still [Prior Art] Switching power supply in the market; la regulated power supply '岐 式 遍 ❹ ❹ has replaced the linearity adjustment controller to control power: 曰 == is: must rely on - pulse wide The width adjustment controller adjusts the pulse width according to the raw feedback signal to adjust the two or two: current production to generate the appropriate conduction time and;; the device uses, the feedback method can not reach the enthalpy rate requirement 'so most The switching power supply is ^^ = connected to the second side: the underside is obtained, and the number is transmitted to the primary side via the optical coupler to control the pulse wave. Therefore, the optocoupler, the feedback two or two; the output pulse detector of the second, the feedback device, and the current-limiting component: the second: the resistance and the operational amplification are::: the exchange-controlled power supply of the control Source-supply power first circuit actuation by DC wheel input / melon /, 丨 L,, work start resistance R2 power (10) to pulse width adjuster 充电 charge degree adjustment (four) start output pulse control power transistor two M312119, When the crystal Q1 is turned on, the current is supplied from the DC input power supply VIN through the secondary side of the transformer T1, the secondary side of the transistor Q1 to the negative end of the input voltage VIN, and the secondary side because the polarity of the diode D3 and the output winding are opposite. The energy cannot be transferred from the secondary side to the output end. At this time, the energy is temporarily stored in the transformer T1. When the voltage of the primary current detecting resistor R6 reaches the reference voltage value, the power transistor QU is turned off. Because the polarity of the diode D3 and the output winding becomes positive, the storage φ of the transformer D1 is transferred to the output terminal V0, and the output capacitor C4 passes through the charging and output regulation point of the cycle. On the other hand, the voltage generated by the primary side auxiliary winding supplies current to the power supply voltage V c C via the resistor R1 and the diode D , to provide pulse width adjustment (4) ϋ m ❺ power supply, auxiliary winding (four) - path then "resistance R1 and diode The body D2 and the capacitor C6 are rectified into a DC voltage, and then connected to the pulse width adjuster and the voltage feedback input pin VFB of the U1 via the resistors R3 and R4. The voltage of the capacitor C6 will reflect the change of the output terminal v〇. Since the voltage drop of the output rectifying diode D3 varies with the load level and the electric power, the voltage of one C6 also affects the size of the conduction period, so that the detection method of the electric house from the secondary side can not be completed. The secondary side output voltage V〇=change, so the output voltage regulation rate is high, and it is unable to provide a stable power supply. The output terminal usually needs to be connected with a dummy load resistor R8, so that the light load does not cause excessive drift when the load is light. Level, because the connection-false load resistance R8 is required, the input power of the GREEN MODE is not met, and the power is lower than the G.3W specification. At the same time, the input current circuit is not provided, and the current will follow the wheel. The output voltage rises and rises. The circuit protection needs to limit the output power according to the J detection resistor R6 feedback signal. The power supply of the pulse wave 7 M312119 width adjuster m should be lower than the minimum power supply wave pulse width adjustment controller m', etc. When the voltage level is started, the output is again output, and the whole seam == rate can be effectively reduced at this time. u Input power circuit = exchange type for feedback control _ / '❼考弟二图' Output terminal vo, slow resistance R8, R9 ^ after the pressure is input to the input terminal of the feedback regulator U3, back to the _· u3 wheel "controls the light-emitting diode current of the secondary side of the optical coupler U2, and then converts to the primary side current signal control pulse The voltage width adjuster ♦ presses back 俨 _ the voltage of the input pin WB. Under the output load of the pulse, the voltage of the voltage feedback input pin VFB will be fixed. When the load changes, the voltage of the input pin VFB will be adjusted accordingly: Maintain stable Voltage output. - The secondary side auxiliary winding also starts to charge capacitor C2 and supply the voltage required for the pulse width adjustment m power supply because the voltage exceeds the source voltage. In addition, in the second figure, the second and second undersides use the resistor, R6, R7, capacitor C4 and transistor Q12 to form a turn-off current limiting circuit. When the voltage of the resistor R6 exceeds the base-emitter junction voltage of the transistor q12. The time limit flow starts to move. Transistor Q12 collector control light combiner secondary side two: light diode current, so that the primary side pulse width adjustment controller υ 〗 〖 wave width is limited, this output current limiting circuit due to the base _ emitter The junction voltage is easy to change with temperature, so the accuracy of the accurate shirt height is more suitable for low-cost charger circuits. The third figure is the conventional secondary side feedback control switching power supply crying-circuit block diagram, please refer to the third figure, its accurate high height is applicable ^ M312119 high power and large output current exchange power supply wire , Xiangxiang operational amplifier U4 A, U4B and feedback regulator U3, optical converter is still used as voltage feedback and output current limiting circuit. Among them, the feedback regulator U3 is here - reference power, the device, which provides a stable "25V reference voltage to the voltage feedback control operation amplifier MIKA and the input current limit (four) operational amplifier (four), electricity (four) calculation amplification H U4A and the output current limit control amplifier side of the 2 terminals are connected to a diode D3, D4 and then connected to the light and light combiner U2 secondary pulse width to achieve voltage regulation and current limit: skin: = U1 loss The use of many parts, high cost is its shortcoming. The accuracy of the edge is often riddled by the porch ^ how to create a kind -: under-back feedback control exchange-type electrical evaluation - output reaches current limit, type of oblique The flow can still be controlled to remain unchanged, but to achieve the round-trip and drop-off, but the output power is the place where the author wants to actively explore. For the purpose of staying in the 4th, [new content] It is contrary to the shortcomings of the above-mentioned practices, creating a heart and mind The study overcomes the problem of ^: untreated in the shoulder money' to develop a second two-stage sampling and retention control circuit; two-type power supply injury in the non-continuous town operation when the harmonic voltage turns two: side Auxiliary winding system to produce the material leakage double function t' line as a back shot and output negative load There is a stable electric two-out, the wheel-in electric wheel output voltage drops but the output current can still be controlled to maintain = to the electric ^312119 to achieve the purpose of output over-current protection. The: f " purpose is to provide - type - secondary side feedback control The switching power supply 仏, /, the fine sampling and retention control circuit obtains the corner voltage value of the harmonic electric house when the primary auxiliary winding is operated in the discontinuous mode as the feedback control, and when the output reaches the current limit, the wheel is turned off. The voltage drops but the output current can still be controlled to maintain the same, and the purpose of the overcurrent protection is achieved. The purpose of the current supply is to provide a sub-back feedback control switching power supply secret transformer, which has a primary winding, - Auxiliary: group 5 = winding = _ pole winding connection - power supply; - power electric crystal (four) two ^ = ϋ '1 - secondary side feedback control pulse width adjustment sampling and retention control circuit, which is connected to the auxiliary winding Amplifying the thief's connection to the sampling and retention control circuit; a branching device 2 connected to the sampling and retention control circuit; a multiplier, a connection thereof; a comparator-connector connecting the error amplifier and the power „−弟二 comparator“ is connected to the first comparator and the multiplier; a rate limiting compensation circuit connected to the multiplier; a control switch 'which is connected to the power source and the power_compensation circuit;-output driver a continuous transistor, a flip-flop connected to the output driver, a vibration/production device connected to the flip-flop; a leading edge cancellation circuit connected to the ^R gate The first comparator and the second comparator are connected. The edge 4 divides the circuit; wherein, when the electric dust of the electric wave reaches the primary side: when the control pulse width adjustment controller starts voltage, a low voltage lock two-way UVL0 controls the control switch to be turned on, the power limit compensation The circuit generation rate F f] is a complementary voltage, and the power limitation compensation voltage is transmitted to the input end of the multiplier M312119; the oscillation generator transmits a communication number to the input end of the flip-flop to make the flip-flop The Q output is converted from a low level voltage to a high level voltage, and the output driver turns on the power transistor; the voltage of the auxiliary winding is fed back to the sampling and retention control circuit to generate a voltage value, and the voltage value is a reference voltage is outputted by the error amplifier to an error amplification value voltage, and the error amplification value voltage is divided by a plurality of resistors to generate a control electric quantity, and the control voltage is transmitted to a reverse wheel end of the first comparator; the voltage value is After the other path is stepped down by the voltage divider, a multiplicative value is multiplied by the power limiting compensation voltage and a second reference voltage is generated to generate a current limiting reference voltage. The current limiting reference voltage is transmitted. To another inverting input of the first comparator; a source voltage of the power transistor is transmitted to a non-inverting input of the first comparator and a non-inverting input of the second comparator; When the source voltage is greater than the current limiting reference voltage or the control voltage, a cutoff signal is generated, and the cutoff signal (4) QR _ is generated after the circuit is removed - a reset signal

To the & input of the flip-flop, the reset signal causes the positive and negative output terminals to change from a high-level voltage to a low-level voltage. The purpose of reducing the power output voltage but protecting the output I current is exhausted. Therefore, when the rotation reaches the current limit, the wheel current can still be controlled to maintain the same 'to achieve the output of the L-application method】, so that the responsible review committee fully understands the original; by: by: ϊ specific examples,卞 评 , , , M M 312 M M M M 312 312 312 312 312 312 312 312 312 312 312 312 312 312 312 312 312 312 312 312 312 312 M 312 M M M M 312 312 M M 312 M 312 M M M The second embodiment of the present invention is a control signal diagram of the preferred embodiment. Please refer to the fourth, fifth and sixth figures at the same time. The primary side feedback control switching power supply includes a flyback transformer T having an initial m-drain winding and a secondary winding, the primary winding is connected to a private source, and the power pack is connected to the Japanese body Q1. Primary winding; primary side feedback control pulse width adjustment control H m having a sampling and retention control circuit 2 connected to the auxiliary winding; an error amplifier AMpl connected to the sampling and retention control circuit 2; - voltage divider DIVIDER , its connection sampling and insurance Leave control circuit 2; - multiplier MULT connected to the voltage divider

DIVIDER; - first comparator c 〇 Ml connected to error amplifier AMP1 and power transistor Q1; - second comparator COM2 connected to first comparator C0M1 and multiplier MULT; - power limit compensation circuit 1, connected Multiplier MULT; - Control switch sw, which is connected to the power supply and power limit compensation circuit 1; an output driver DRIVER connected to the power transistor Q1; - a flip-flop FF1 connected to the output driver DRIVER; - an oscillation generator OSC, Connect the flip-flop FF1; - leading edge cancel circuit LEB, which is connected to the flip-flop FF1; - 〇R gate, which is connected to the first comparator C0M1, the second comparator COM2 and the leading edge cancel circuit LEB; when the power supply voltage VCC is When the resistor R2 and the diode D4 are charged to reach the starting voltage of the pulse width adjusting controller U1, the pulse width adjusting controller U1 starts to operate, and the low voltage locking circuit UVLO outputs a UVO signal to make the internal voltage stabilizing circuit BAND 12 M312119 , gap A reference voltage is output and a compensation control switch sw is turned on, and the +-resistance R2 is switched to a power limit compensation circuit 1 connected to the multiplier MULT. The variation of the voltage VIN produces different power limit compensation voltages WL such that the power limit points at high and low voltage inputs tend to be uniform. The oscillation of the pulse width adjustment controller generates a crying OSC output a communication number to the s wheel of the flip-flop FF1, so that the positive and negative crying FF1 output terminal Q is converted from the low level voltage to the high level voltage, the first output ς The DRIVER thus outputs a high-level voltage to turn the power transistor Q1 into the reference voltage VCL_ at a low level voltage so that the on-period of the pulse width adjustment controller 被 is limited by the current-limit reference voltage VCL by the lowest period; As the output voltage and the auxiliary winding voltage become higher, the "-S〇FT STAR" start effect is provided. On the other hand, the auxiliary winding starts to generate voltage through the diode D2, the resistor supply power supply voltage VCC, and the corner voltage value of the auxiliary winding voltage in the discontinuous operation mode is passed through the resistor R3. Divided into, electric house feedback input chat VFB $ pulse width adjustment controller m sampling and retention control circuit 2 take the piece of voltage as the internal voltage control and current limit control voltage value v The voltage value VI and the first reference voltage VREF1 are outputted by the error amplifier AMP1, and the error value is amplified by the error amplifier ,ρι, and the voltage terminal COMP is connected to a compensation component (for example, the capacitor C5 or the electric valley and the at least resistor). ) Prevent the error amplifier from 减ρι reducing the situation. The voltage of the error amplification value is divided by the resistors R7 and R8 to generate a control voltage VCTL, and the control voltage VCTL is connected to an inverting input terminal of the M312119 of the first comparator c〇M1, and the non-inverting of the first comparator C0M1 The input terminal is further connected to the current detecting side resistor R6 to detect the primary side current detecting voltage VCS, and the primary side current detecting voltage VCS of the non-inverting input terminal is compared with the control voltage VCTL of the inverting input terminal, when the primary side current detecting When the measured voltage VCS is greater than the control voltage VCTL, a cutoff signal is generated. The LEA gate is removed to the leading edge canceling circuit LEB (LEADING EDGE BLANKING) to eliminate the primary side current detecting voltage VCS leading edge noise voltage and output a reset signal to the flip-flop The R input terminal of FF1 turns the output terminal Q of the flip-flop FF1 from the high-level voltage to the low-level voltage, and the first output driver DRIVER thus outputs a low-level voltage to turn the 眷 power transistor Q1 into a non-conducting state. The oscillation generator OSC of the pulse width adjustment controller U1 outputs the conduction pulse signal to the S input terminal of the flip-flop FF1 again, so that the flip-flop FF1 turns the output terminal Q from the low-level voltage to the high-level voltage again. 'The first output driver DRIVER again outputs the high level ·- voltage, so that the power transistor Q1 is turned into the on state again, and the control voltage VCTL and the primary side current detection voltage vcs are compared again, and the cutoff signal is generated through the 0R gate. The edge elimination circuit LEB (LEADING EDGE | BLANKING) eliminates the primary side current detection voltage yes before the edge noise voltage and outputs a reset signal to the input terminal of the flip-flop FF1, so that the output terminal Q of the flip-flop FF1 is high-level. When the voltage is turned to the low level voltage, the first output driver DRIVER controls the power transistor Q1 to turn into a non-conducting state, and repeats the above action to generate a stable output control. The pulse width adjustment controller of the primary side feedback control of the present invention is created. The power limit compensation voltage VPL of Ul is generated by dividing the voltage of the power source by a resistor and then transmitting it to the inverting input terminal of the subtractor 3 to be compared with a third reference voltage VERF3, and the current limiting reference voltage V is generated. The CL is sampled by 14 M312119 and the output voltage of the hold control circuit 2 = the ratio of two to two. After the step-down and the power limit compensation = multiplied by the second reference voltage v, the switch is set to a small amount of electricity. The eaves section is changed from small to large to prevent the current from exceeding the limit. Π Tea test—VCL varies with the V〇 voltage at the output, so the output current can be controlled within the limits.

As described above, in which the feedback input pin WB is connected to a diode D3, the voltage is applied to the negative voltage of the input pin WB to be clamped at the level of the negative 〇7ν) voltage, and the voltage feedback is input. The pin vfb is obtained by the sample fish retention control circuit 2 to obtain a value of the Wei corner voltage stored in the capacitor. The corner voltage value is generated on the one hand by the first error amplifier AMP1 and the resistors R7, R8 to generate the control voltage VCTL, and the other side is generated by the buffer BUFFER, the voltage divider divider, the multiplier MULT plus the second reference voltage VREF2: current limiting reference The voltage VCL, the current-limit reference voltage VCL is equal to the value of the output voltage of the voltage divider DIVIDER and the power limit compensation voltage vpL plus the second reference voltage VREF2. The input voltage VIN is controlled by a compensation switch SW and a resistor R5 to generate a voltage division input subtractor 3 of the reverse wheel input terminal, which compares the output power limit compensation voltage VPL with the third reference voltage VREF3. The primary current detection voltage vcs will be compared with the current limiting reference voltage VCL and the control voltage vcTL respectively. When the primary side current detection voltage Vcs is greater than one of the voltages, the cutoff signal will be output, and the cutoff signal will be eliminated by the leading edge. The circuit LEB (LEADING EDGE BLANKING) eliminates the primary side current detection voltage VCS leading edge noise voltage, and outputs a reset 15 M312119 to the R input of the positive and negative FF1, so that the positive and negative ends of the output terminal Q. The standard private voltage is converted to a low level voltage, and the first output driver driver thus outputs a low level voltage, so that the power transistor Q1# is in a non-conducting state. The phase shift WPHASE SHIFT generates a blank signal muscle eight fox input sampling and the control circuit 2, so that the circuit sampling timing is after the blank signal BLANK to avoid sampling in the voltage feedback input pin VFB voltage ringing (RINGING) area. The seventh picture is the graph of the ideal output current limit of the creation. The maximum output of the output is limited to the limit current value. When the output voltage drops to a set value, the output current is folded back. The eighth figure is a block diagram of the internal circuit of the sampling and retention control circuit of the primary side feedback control of the parental switching power supply in the preferred embodiment of the present invention, which uses the voltage feedback voltage of the input pin VFB. The blank signal - the flat voltage level after BLANK is stored and follows the voltage change. § The private voltage feedback input pin VFB voltage reaches the harmonic start when turning to another steep slope change, from sampling and retention. The control circuit obtains the voltage V1 of 10 and immediately stops the voltage change following the voltage feedback input pin VFB and memorizes the voltage value at the storage corner as the control voltage of the internal voltage regulation control and the current limit L system, as shown in the eighth figure. The blank signal BLANK will control: the private day and body Q4 is turned on and the voltage VI is discharged to zero. After the blank signal BLANK is finished, the discharge is stopped. The operational amplifier AMp2 and the transistor Q2 form a voltage with a flat slope. The voltage is fed back to the input pin, and the voltage transfer of VFB is stored on the capacitor ο. The voltage of the capacitor c2 is the voltage of the control and the voltage VI, and the bias voltage BIAS controls the transistor Q5 to be turned on to form a discharge battery 16 M3. 12119 flow Idschg, the discharge current Idschg is set to be much smaller than the voltage follower controlled charging mhg' purpose is to generate a voltage change with the voltage of the input pin vfb, the voltage feedback to the input pin VFB Voltage and blank signal f Tiger BLANK #反信号信号 and M AND input flip-flop FF3 control transistor Q5 turn-on and turn-off, to obtain voltage v Bu-flip FF2 to prevent false trigger action after the first harmonic Occurs, whereby the sampling and retention control circuit can obtain the corner voltage value of the spectral voltage when the discontinuous cavity is in operation as the feedback control. _ As mentioned above, this creation uses the sampling and retention control circuit to obtain the value of the corner voltage of the primary auxiliary winding in the discontinuous mode 1 (four) (four) wave voltage as the feedback control. When the output reaches the current limit, the output voltage drops, and the output current remains. The control can be maintained unchanged, and the output overcurrent protection can be achieved; in terms of the availability of the industry, the production of σα derived from the creation can fully satisfy the current market demand.

This creation is disclosed in the above article. (4) The skill of the book is understood to be that the _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ The idea is that any changes and permutations, such as the embodiment, should be made to cover the creation of this creation. Therefore, the scope of protection of this sword is subject to the definition of patent scope in the following text. [Simple description of the diagram] The first diagram is a circuit diagram of a conventional circuit. Secondary side feedback controlled switching power supply

M312119 The second figure is a block diagram of a conventional switched-mode power supply circuit for secondary side feedback control. The third figure is another circuit block diagram of a conventional secondary power supply controlled switching power supply. The fourth figure is a block diagram of the primary side feedback control switching power supply circuit of the preferred embodiment of the present invention. The fifth figure is a block diagram of the internal circuit of the pulse width adjustment controller shown in the fourth figure. Figure 6 is a control signal diagram of a preferred embodiment of the present invention. The seventh picture is a graph of the ideal output current limit of the creation. Figure 8 is a block diagram showing the internal circuit of the sample and hold control circuit in the primary side feedback control switching power supply of the preferred embodiment of the present invention. [Main component symbol description] ui pulse width adjustment controller U2 optocoupler U3 feedback regulator U4A, U4B operational amplifier UVLO low voltage lockout circuit UVO signal BAND GAP internal voltage regulator circuit SW compensation control switch M312119

Cn Capacitor 1 Power Limit Compensation Circuit 2 Sample and Retention Control Circuit 3 Subtractor MULT Multiplier VIN Input Voltage VCC Supply Voltage V0 Output Terminal VCL Current Limit Reference Voltage VPL Power Compensation Voltage VCTL Control Voltage OSC Oscillator Generator FF1, FF2, FF3 Positive Counter DRIVER first output driver Q1 power transistor Q2, Q3, Q4, Q5, Q12 transistor Dn diode VFB voltage feedback input pin T1 transformer AMP1 error amplifier AMP2 operational amplifier COMP output voltage terminal C0M1 first comparator COM2 second comparator 19 M312119 LEB leading edge elimination circuit DIVIDER voltage divider BUFFER buffer VERF1 first reference voltage VERF2 second reference voltage VERF3 third reference voltage VCS - secondary side current detection voltage ldschg discharge current lchg charging current BALNK blank Signal BIAS bias VI voltage

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Claims (1)

M312119 IX. Patent Application Range 1. A primary-side feedback control switching power supply, comprising: a flyback transformer, and a right _ ^ buckle A ..., a primary winding, an auxiliary winding and a primary winding The primary winding is connected to a power supply; a power transistor is connected to the primary winding; a primary side feedback control pulse width adjustment controller, which has a sampling and control circuit connected to the auxiliary winding; an error amplification thief connected to the sampling and retention control circuit; a voltage divider Connecting the sampling and retention control circuit; a multiplier 'connecting the voltage divider; - a first comparator 'connecting the error amplifier and the power transistor - a second comparison n ' connecting the first comparator and the a multiplier; a power limit compensation circuit connected to the multiplier; - a control switch 'connected to the (four) power supply and the power off compensation circuit, a turn-off driver connected to the power transistor; a flip-flop connected to the output driver An oscillating generator connected to the flip flop; a uranium edge eliminating circuit connected to the flip flop; and a 〇R gate connected to the first comparator, the second comparator and the leading edge eliminating circuit; Wherein, when the voltage of the power supply reaches the starting voltage of the primary side feedback control pulse wave degree adjustment controller, the health lock circuit controls the control switch to be turned on, and the power limit compensation circuit is - power limit compensation 21 M312119 2 voltage 'the power limit compensation voltage is transmitted to the input of the multiplier; the enable = generator generates a conduction number to the s input of the flip-flop, the Q output of the upper and lower The terminal turns from the low level voltage to the high level voltage, and the f wheel drive driver turns on the power transistor; the voltage of the auxiliary winding returns to the sampling and retention control circuit to generate a voltage value, and the voltage value is measured by the voltage Error amplifier output - error amplification value =, the error amplification value voltage is generated by a plurality of resistors to generate a control voltage to the opposite end of the first comparator; the electricity = the voltage is converted After the pressure, the power is input to the voltage, and the output voltage of the recording method is added. - the second reference voltage is generated - the current limiting reference voltage is passed. The current limiting reference voltage is transmitted to the second comparator. a source voltage of the power transistor is transmitted to the first ratio non-inverting input terminal and a non-inverting input terminal of the second comparator; the source voltage is greater than the (four) voltage or the current limiting reference plane When the second _ money number, _ 0R _ to the financial edge Electric: R = a steal to the number of the flip-flop input terminal, the reset information twenty-two end by a high level into a low level electrical power i, of the output driver causes the power transistor is not conducting. 2. The primary side feedback control switching mode described in item 1 wherein the error amplifier and the _compensation element oscillate the error amplifier. The _ secondary side source supply described in item 2 of the patent, wherein the compensating element is connected to at least one resistor. twenty two