WO2018032949A1

WO2018032949A1 - Self-driving winding circuit and control method thereof, and switching power supply

Info

Publication number: WO2018032949A1
Application number: PCT/CN2017/094483
Authority: WO
Inventors: 欧阳艳红; 吴曙松
Original assignee: 中兴通讯股份有限公司
Priority date: 2016-08-16
Filing date: 2017-07-26
Publication date: 2018-02-22
Also published as: CN107769562A

Abstract

A self-driving winding circuit and a control method thereof, and a switching power supply. A transformer auxiliary driving winding (1) coupled to a voltage of a primary transformer in a primary circuit to obtain a voltage signal (101, 201, 301, 401, 501, 601, 701, 801) alternating between positive and negative potentials. Output terminals of the transformer auxiliary driving winding (1) are connected to a first transistor in a secondary circuit, and an input terminal of an invertor circuit (2), respectively. An output terminal of the invertor circuit is connected to an input terminal of a power driving circuit (3). An output terminal of the power driving circuit (3) is connected to a second transistor in the secondary circuit. When the transformer auxiliary driving winding outputs a positive voltage signal, the first transistor is driven; and when the transformer auxiliary driving winding outputs a negative voltage signal, the invertor circuit performs an inversion process on the voltage signal, and then the power driving circuit drives the second transistor. The self-driving winding circuit and the control method thereof utilize the transformer auxiliary driving winding to implement driving of the two transistors in the secondary circuit, simplifying transformer winding design, and increasing power supply efficiency.

Description

Winding self-driving circuit and control implementation method thereof, switching power supply circuit

Technical field

The present disclosure relates to the field of power electronics, and in particular, to a winding self-driving circuit, a control implementation method thereof, and a switching power supply circuit.

Background technique

In the field of switching power supplies, medium and small power switching power supplies generally use an active clamp forward topology, and the secondary side circuit uses a synchronous rectification structure. In order to achieve high efficiency and low cost, according to the active clamp forward topology, the secondary side synchronous rectifier uses a winding self-driving mode. When the secondary circuit has multiple switching tube scenarios such as a rectifier tube and a freewheeling tube, the current driving method uses two auxiliary windings to respectively drive the rectifier tube and the freewheeling tube existing in the secondary circuit. This kind of scheme leads to complicated design of the transformer winding, and the position of the transformer power winding is occupied by the driving winding, which causes the winding window of the transformer power winding, the diameter of the winding, the number of parallel turns, etc. to be reduced, which indirectly affects the power efficiency.

Summary of the invention

According to the winding self-driving circuit and the control implementation method thereof and the switching power supply circuit provided by the embodiments of the present disclosure, the main technical problem is to solve the problem that the existing two switching tubes existing for the secondary circuit need to be driven by one auxiliary winding respectively. The problem that the transformer winding design is complicated and affects the power supply efficiency.

To solve the above technical problem, an embodiment of the present disclosure provides a winding self-driving circuit, including:

Transformer auxiliary drive winding, reverse circuit and power drive circuit;

The transformer auxiliary drive winding couples the voltage of the main transformer in the primary side circuit to obtain a positive and negative alternately converted voltage signal; the output end of the transformer auxiliary drive winding and the first switch tube in the secondary side circuit and the opposite Connected to the input end of the circuit, the output end of the reverse circuit is connected to the input end of the power drive circuit, and the output end of the power drive circuit is connected to the second switch tube in the secondary circuit;

When the transformer auxiliary driving winding output is a positive voltage signal, the first switching transistor is driven, and when the output is a negative voltage signal, the voltage signal is reverse processed by the reverse circuit, and then the power driving circuit is used. Driving the second switch tube.

The embodiment of the present disclosure further provides a switching power supply circuit, including:

a primary side circuit, a secondary side circuit, and a winding self-driving circuit as described above;

The primary side circuit is coupled to the secondary side circuit, and the transformer auxiliary driving winding couples a voltage of a main transformer in the primary side circuit to obtain a positive and negative alternating voltage signal; the output of the transformer auxiliary driving winding The end is connected to the first switch tube in the secondary circuit, and the output end of the power drive circuit is connected to the second switch tube in the secondary circuit;

Driving the first switch tube when the transformer auxiliary drive winding output is a positive voltage signal, and outputting a negative power When the signal is pressed, the voltage signal is reversely processed by the reverse circuit, and the second switching transistor is driven by the power driving circuit.

The embodiment of the present disclosure further provides a winding self-driving circuit control implementation method, which is applied to a winding self-driving circuit including a transformer auxiliary driving winding, a reverse circuit, and a power driving circuit, and the method includes:

Connecting the output of the transformer auxiliary drive winding to the first switch and the reverse circuit input of the secondary circuit, respectively, and connecting the output of the reverse circuit to the input of the power drive circuit, and driving the power The output end of the circuit is connected to the second switch tube in the secondary circuit;

The transformer auxiliary driving winding couples the voltage of the main transformer in the primary side circuit to obtain a positive and negative alternating voltage signal;

Driving the first switch tube by the transformer auxiliary drive winding output as a positive voltage signal;

The second switching transistor is driven by the power driving circuit by performing a reverse processing on the voltage signal of the transformer auxiliary driving winding output by the reverse circuit.

The beneficial effects of the present disclosure are:

A winding self-driving circuit and a control implementation method thereof, and a switching power supply circuit according to an embodiment of the present disclosure, wherein the winding self-driving circuit includes a transformer auxiliary driving winding, a reverse circuit, and a power driving circuit; and the transformer auxiliary driving winding is coupled to the primary side circuit The voltage of the main transformer is obtained by alternating positive and negative voltage signals; the output of the auxiliary drive winding of the transformer is respectively connected with the first switch tube and the input end of the reverse circuit in the secondary circuit, and the output of the reverse circuit and the input of the power drive circuit The end connection, the output end of the power drive circuit is connected with the second switch tube in the secondary circuit; when the output of the transformer auxiliary drive winding is a positive voltage signal, the first switch tube is driven, and when the output is a negative voltage signal, the reverse circuit pair is used. After the voltage signal is reverse processed, the second switching transistor is driven by the power driving circuit. The present invention can realize the driving of the two switching tubes in the secondary circuit by using a transformer auxiliary driving winding, simplifying the transformer winding design, reducing the cost, avoiding occupying the transformer power winding position, and making the transformer power winding winding window and winding. Diameter, parallel turns, etc. can be optimized to improve power efficiency.

DRAWINGS

1 is a schematic structural diagram of a winding self-driving circuit according to Embodiment 1 of the present disclosure;

2 is a schematic structural diagram of another winding self-driving circuit according to Embodiment 1 of the present disclosure;

3 is a schematic structural diagram of a winding self-driving circuit according to Embodiment 2 of the present disclosure;

4 is a schematic diagram of signals according to a second embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a circuit structure in an active clamp forward topology according to Embodiment 3 of the present disclosure; FIG.

6 is a schematic diagram of a circuit structure of another implementation in an active clamp forward topology according to Embodiment 3 of the present disclosure;

FIG. 7 is a schematic diagram of a circuit structure in another active clamp forward topology according to Embodiment 3 of the present disclosure; FIG.

FIG. 8 is a circuit diagram of another implementation in another active clamp forward topology according to Embodiment 3 of the present disclosure. Schematic diagram

FIG. 9 is a schematic diagram of a circuit structure in a single-ended forward resonant reset topology according to Embodiment 3 of the present disclosure; FIG.

FIG. 10 is a schematic diagram of a circuit structure in a flyback topology according to Embodiment 3 of the present disclosure.

detailed description

The technical solutions in the embodiments of the present disclosure are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present disclosure. It is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without departing from the inventive scope are the scope of the disclosure.

Embodiment 1:

Referring to FIG. 1, the winding self-driving circuit provided in this embodiment includes a transformer auxiliary driving winding, a reverse circuit, and a power driving circuit.

The transformer auxiliary drive winding in the embodiment is coupled to the main transformer in the primary side circuit, and is set to a voltage signal in which the voltage of the main transformer in the primary side circuit is alternately converted. The output end of the auxiliary drive winding of the transformer is respectively connected with the first switch tube and the input end of the reverse circuit in the secondary circuit, and the output end of the reverse circuit is connected with the input end of the power drive circuit, and the output end of the power drive circuit and the secondary side circuit The second switch is connected;

When the output of the transformer auxiliary drive winding is a positive voltage signal, the first switch tube is driven, and when the output is a negative voltage signal, the voltage signal is reversely processed by the reverse circuit, and then the second switch tube is driven by the power drive circuit. The power driving circuit can power-amplify the voltage signal from the reverse circuit to obtain a driving signal of the second switching transistor.

The embodiment of the present disclosure can drive the driving of the two first switching tubes and the second switching tube in the secondary circuit by a transformer auxiliary driving winding, which can simplify the transformer winding design, reduce the cost, and avoid occupying the transformer power winding position, so that Transformer power winding winding window, winding diameter, parallel turns, etc. can be optimized to improve power efficiency.

Exemplarily, the transformer auxiliary drive winding in this embodiment may directly adopt an auxiliary winding of the main transformer, the first connection end of the auxiliary winding is grounded, and the second connection end is connected to the first switch tube and the reverse circuit. This further simplifies the transformer winding design and saves costs.

Referring to FIG. 2, the winding self-driving circuit in this embodiment further includes a boosting circuit and an auxiliary power supply circuit;

The input end and the output end of the boosting circuit are respectively connected with the output end of the transformer auxiliary driving winding and the input end of the reverse circuit; the auxiliary power supply circuit comprises a unidirectional charging circuit, and the input end of the unidirectional charging circuit is connected with the output end of the boosting circuit The output is connected to the circuit to be powered;

When the output of the boosting circuit is a positive voltage signal, the unidirectional charging circuit is charged while supplying power to the circuit to be powered; when the output of the boosting circuit is a negative voltage signal, the unidirectional charging circuit supplies power to the circuit to be powered.

The following is an example of a combination of the entire control process. See Figure 2,

The auxiliary drive winding of the transformer couples the voltage signal from the main power amplifier to positively and negatively change the energy, which is recorded as The 101, 101 can drive the first switching transistor of the secondary circuit directly or after further processing (eg, driving voltage limiting). 101 is input to the boosting module circuit, and after the boosting circuit, obtains a voltage signal with a more stable amplitude in the full input voltage range and an auxiliary power supply voltage signal, which is recorded as 102. 102 input to the auxiliary power supply circuit to obtain the power supply voltage, which can be directly Or after processing (such as linear voltage regulation and the like), power is supplied to the circuit to be powered (for example, the control circuit portion), and is recorded as 103. 102 is input to the signal inversion circuit to obtain a voltage signal that is logically inverted with respect to 102, which is recorded as 104. After passing through the power driving circuit, the power amplified

driving signals

105, 105 are used to drive the second switching transistor of the secondary circuit.

It should be understood that the first switch tube in the embodiment is a rectifier tube, and the second switch tube is a freewheel tube; or the first switch tube is a freewheel tube, and the second switch tube is a rectifier tube.

In an embodiment of the present disclosure, the boosting circuit includes a boosting capacitor and a boost unidirectional conduction control device;

One end of the boosting capacitor is connected to the output end of the auxiliary drive winding of the transformer, and the other end is connected to the output end of the boosting single-conducting control device, and the input end of the boosting single-conducting control device is grounded;

When the output voltage signal of the auxiliary drive winding of the transformer is negative, the boost capacitor is charged, and the output voltage signal of the auxiliary drive winding of the transformer is positive, and is superimposed with the voltage on the boost capacitor and sent to the auxiliary power supply circuit and the reverse circuit.

The boosting single-conduction control device in this embodiment may be an example of a boost diode. The second connection end of the boost capacitor is connected to the cathode of the boost diode, and the anode of the boost diode is grounded.

The boosting circuit in this embodiment may further include a boosting resistor adjusting subcircuit connected in parallel with the boosting one-way control device. The boost resistor adjustment sub-circuit can adjust the boost capacitor storage capacity.

The unidirectional charging circuit in this embodiment includes a power supply single-conduction control device and an auxiliary power supply capacitor, and the input end of the power supply single-conduction control device is connected to the output end of the boost single-conduction control device; the auxiliary power supply capacitor is connected to the power supply single guide at one end. The output end of the control device is grounded, and the other end is grounded; the auxiliary power supply capacitor is simultaneously connected with the circuit to be powered to supply power to the circuit to be supplied.

The power supply single-conduction control device in this embodiment may be an auxiliary power supply diode. The anode of the auxiliary power supply diode is connected to the cathode of the boost diode, and is connected to the second connection end of the boost capacitor; the first connection end of the auxiliary power supply capacitor The cathode of the auxiliary power supply diode is connected, and the second connection terminal is grounded. The voltage obtained on the auxiliary supply capacitor is directly set to supply power to the control portion circuit or to supply power to the portion of the circuit to be supplied (for example, the control circuit portion) after further voltage stabilization processing.

It should be understood that the unidirectional conduction devices in this embodiment are not limited to diodes, and any device or circuit capable of achieving unidirectional conduction can be used.

The reverse circuit in this embodiment includes a conduction speed control resistor, a pull-up resistor and a reverse transistor; one terminal of the conduction speed control resistor is connected to the cathode of the boosting unidirectional control device, and the other terminal is connected in reverse. The base of the transistor; the emitter of the reverse transistor is connected to the ground, the collector is connected to one end of the pull-up resistor, and the other end of the pull-up resistor is connected to the auxiliary power supply.

The conduction speed control resistor in this embodiment can be realized by a resistor, hereinafter referred to as a first reverse resistor, and the pull-up resistor can also be realized by a resistor, hereinafter referred to as a second reverse resistor. The reverse transistor can use various three poles Tubes, MOS tubes, etc. are implemented. The following uses an example of a reverse triode as an example. At this time, the first connection end of the first reverse resistor is connected to the cathode of the boost diode, and the second connection end of the first reverse resistor is connected to the base of the reverse triode. The emitter of the reverse triode is connected to the ground, the collector is connected to one end of the second reverse resistor, the other end of the second reverse resistor is connected to the auxiliary power supply, and the reverse circuit portion is arranged to input the signal, that is, the boost circuit The output signal is inverted.

The power driving circuit in this embodiment includes a first power transistor and a second power transistor, the base of the first power transistor is connected to the base of the second power transistor, and the pull-up resistor is connected at the same time; the collector connection of the first power transistor The auxiliary power supply; the collector of the second power transistor is connected, and the emitters of the first power transistors are respectively connected to the emitters of the second switching transistor and the second power transistor. The power transistor in this embodiment can also be a variety of triodes, MOS tubes, and the like. The following is an example in which the first power transistor drives the transistor with NPN power and the second power transistor is a PNP power driven transistor. At this time, the base of the NPN power driving transistor is connected to the base of the PNP power driving transistor, and at the same time, the second reverse resistance of the signal inverting circuit portion is connected. The collector of the NPN power drive transistor is connected to the auxiliary power supply, and the collector of the PNP power drive transistor is connected to the ground. The emitter of the NPN power drive transistor is connected to the emitter of the PNP power drive transistor, which is used to drive the second switch of the secondary side.

It can be seen that the embodiment uses a transformer auxiliary winding to realize the driving of the rectifier tube and the freewheeling tube, and at the same time, obtains an auxiliary supply voltage with a relatively stable input voltage range, simplifies the design of the transformer and the inductor winding, and improves the power supply efficiency. The winding self-driving circuit assists the supply voltage to establish fast and the voltage is stable, so that the control circuit part works stably, and the performance and reliability of the power supply are improved. By using the winding self-driving circuit, the switching tube can easily realize that the gate driving voltage does not exceed the specification limit under the premise of satisfying sufficient driving voltage, thereby improving the efficiency and reliability of the power supply as a whole.

Embodiment 2:

For a better understanding of the present disclosure, the present disclosure is further illustrated by way of example with a winding self-driving circuit of an exemplary configuration. Referring to Figure 3, Na is the auxiliary drive winding of the transformer. One end of the auxiliary drive winding of the transformer is connected to the ground, and the other end provides an output signal, denoted as 201. The signal 201 alternates with the positive and negative voltages of the main transformer of the primary circuit, as shown in Fig. 4. In the signal diagram of 201, the positive pressure value reached by setting 201 is V positive, and the negative pressure value reached by 201 is V negative. The 201 signal can be directly or after being processed to drive a set of switching transistors of the secondary circuit, hereinafter referred to as a first switching transistor.

The boosting circuit includes a boosting capacitor Cp, a boosting diode Dp, and a boosting resistor Rp. When the signal of 201 is negative, Cp is charged by Dp, and the capacitance of the parameter Cp is selected so that the voltage V is always maintained on Cp. When the 201 signal is positive, the voltage V on the winding is positively superimposed with the voltage V on the boosting capacitor Cp, and is V positive + V negative after superposition, and is recorded as 202 as the output signal of the boosting circuit. The resistor Rp of the boost circuit is set to balance the voltage across the boost capacitor so that the 202 signal is the actual desired signal.

Since there is always a right positive left negative voltage V negative on Cp, when the 201 signal is switched from high level to low level, when the 201 signal reaches 0V, the 202 signal has a voltage V negative; and the 201 signal is from When the low level is switched to the high level, when the 201 signal reaches 0V, the 202 signal already has a voltage V negative, as shown in FIG.

The auxiliary power supply circuit includes an auxiliary power supply diode Dc and an auxiliary power supply capacitor Cc. When the signal of 202 is high, Cc is charged by Dc and power is supplied to the control circuit at the same time; when the signal of 202 is low, Dc is turned off, and the power supply capacitor Cc supplies power to the control circuit. Therefore, the 203 signal outputted by the auxiliary power supply circuit is a substantially constant voltage, which can be supplied to the control circuit portion directly or after further voltage stabilization processing, as shown in FIG.

The reverse circuit includes a first reverse resistor Rr1, a second reverse resistor Rr2, and a reverse transistor Qr. When the signal of the 202 is high, Qr is turned on, and the collector of the transistor is pulled low, so that the reverse circuit output signal 204 at this time. Low; when the 202 signal is low, Qr is turned off, and Rr2 sets the 204 signal high. The 204 signal and the 202 signal are logically inverted as shown in FIG.

The power driving circuit includes a power driving transistor Qd1 and a power driving transistor Qd2. When the 204 signal is high, Qd1 is turned on, the 205 signal is high, and the amplitude is 204 signal minus the conduction voltage drop of the transistor be junction; the 204 signal is When low, Qd2 turns on and pulls the 205 signal low. The 205 signal is set to drive another set of switching tubes on the secondary side, hereinafter referred to as a second switching tube.

From the above analysis, there is a time difference between the 202 signal and the 201 signal reaching 0V, so that there is a time difference between the subsequent 205 signal and the 201 signal, and the time difference is the dead time of the two sets of switching tubes on the secondary side. In practical applications, the dead time can be adjusted by adjusting Rr1, or by changing Rr1 to a series forward or reverse diode. In the mode of use in Figure 2, increase Rr1, then 202 is high, Qr is turned on later, 204 is pulled lower later, so that the rectifier corresponding to 205 signal is turned off later; when Rr1 is added, 202 is When low, Qr turns off later, and 204 is set higher later, so that the rectifier corresponding to the 205 signal is turned on later. When Rr1 is reduced, the circuit operates in the opposite direction.

Through the winding drive circuit shown in FIG. 4, the two sets of switching tubes of the secondary side circuit can be driven by one winding, and a boost circuit is shared to obtain a relatively constant auxiliary power supply under the condition of full input voltage range.

Embodiment 3:

The embodiment provides a switching power supply circuit including a primary side circuit, a secondary side circuit, and a winding self-driving circuit as described above; the primary side circuit is coupled to the secondary side circuit, and the transformer auxiliary driving winding is coupled to the main transformer in the primary side circuit. The voltage is positively and negatively alternately converted; the output of the transformer auxiliary drive winding is connected to the first switch in the secondary circuit, and the output of the power drive circuit is connected to the second switch in the secondary circuit; When the winding output is a positive voltage signal, the first switching transistor is driven, and when the output is a negative voltage signal, the voltage signal is reversely processed by the reverse circuit, and then the second switching transistor is driven by the power driving circuit.

It should be understood that the primary side circuit and the secondary side circuit in this embodiment can be exemplified by various topologies. The following is a description of the winding self-driving circuit shown in FIG. 3 in combination with various topological application examples.

scene one:

One embodiment of the present disclosure, as shown in FIG. 5, is a clamp mode topology of a LOW SIDE CLAMP (Low Side Active Clamp Circuit) in an active clamp forward topology.

When the primary circuit main controller N_M is turned on, the transformer auxiliary drive winding Na1 is coupled to the voltage on the main transformer, the same name end The connection point 301 signal is a forward voltage proportional to the input voltage, and the 301 signal can be driven directly or after further processing to drive the secondary side synchronous rectifier N_rec, and the 301 signal can also drive the rectifier N_rec after further limiting. At this time, the 302 signal is a superposition of the voltage of the 301 signal and the boosting capacitor Cp1. The 302 signal is charged by Cc1 through the auxiliary power supply diode Dc1 to provide an energy source for the auxiliary power supply 303 signal. At the same time, the 302 signal turns on Qr1 through Rr11, sets the 304 signal low, and then the 305 signal goes low, and the freewheeling tube N_con in the main circuit is turned off.

When the primary circuit main controller N_M is turned off, the voltage across the primary side of the main transformer is the voltage on the clamp capacitor Cclamp minus the input voltage. At this time, the transformer auxiliary drive winding Na1 is coupled to the voltage on the main transformer, and the signal of the same name terminal connection point 301 is negative. The synchronous rectifier N_rec is turned off. The negative voltage value of the 301 signal is a negative voltage proportional to the voltage of the primary side of the main transformer. The boost diode Dp1 is turned on, and Na1 is charged by the boost capacitor Cp1. At this time, since Dp1 is turned on, the 302 signal is turned on. Lower. The auxiliary power supply module is maintained by the power supply capacitor Cc1. The 302 signal is low, Qr1 is turned off, the 304 signal is set high by Rr12, Qd11 is turned on, the 305 signal is high, and the freewheeling tube N_con is turned on in the main circuit.

Scene 2:

One embodiment of the present disclosure, as shown in FIG. 6, is a clamp mode topology of LOW SIDE CLAMP in an active clamp forward topology.

When the primary circuit main controller N_M is turned on, the transformer auxiliary drive winding Na2 is coupled to the voltage on the main transformer, and the signal of the same name terminal connection point 401 is a negative voltage proportional to the input voltage. At this time, the secondary circuit is driven by the 401 signal. The tube N_con is turned off. The boost diode Dp2 is turned on, and Na2 charges the boost capacitor Cp2. At this time, the 402 signal is turned off because Dp2 is turned on. The auxiliary power supply module is maintained by the power supply capacitor Cc2. The 402 signal is low, Qr2 is turned off, the 404 signal is set high by Rr22, Qd21 is turned on, the 405 signal is high, and the rectifier N_rec is turned on in the main circuit.

When the primary circuit main controller N_M is turned off, the voltage at the primary side of the main transformer is the voltage on the clamp capacitor Cclamp minus the input voltage. At this time, the transformer auxiliary drive winding Na2 is coupled to the voltage on the main transformer, and the winding connection point 401 signal is positive, 401 The secondary circuit freewheeling tube N_con, which is driven directly or after further processing, is turned on. The 402 signal is a superposition of the voltage on the 401 signal and the boost capacitor Cp2. The 402 signal charges Cc2 through the auxiliary power supply diode Dc2, which is a source of energy for the auxiliary power supply 403 signal. At the same time, the 402 signal turns on Qr2 through Rr21, sets the 404 signal low, and then the 405 signal is deasserted, and the synchronous rectifier N_rec in the main loop is turned off.

Scene 3:

One embodiment of the present disclosure, as shown in FIG. 7, is a clamp mode topology of a HIGH SIDE CLAMP (High Side Active Clamp Circuit) in an active clamp forward topology.

When the primary circuit main controller N_M is turned on, the transformer auxiliary drive winding Na3 is coupled to the voltage on the main transformer, and the signal of the same name terminal connection point 501 is a forward voltage proportional to the input voltage, and the 501 signal can be driven directly or after further processing. Circuit synchronous rectifier N_rec. At this time, the 502 signal is a superposition of the voltage on the 501 signal and the boosting capacitor Cp3. The 502 signal charges Cc3 through the auxiliary power supply diode Dc3, which is an energy source for the auxiliary power supply 503 signal. At the same time, the 502 signal turns on Qr3 through Rr31, sets the 504 signal low, and then the 505 signal goes low, and the freewheeling tube N_con in the main circuit is turned off.

When the primary circuit main controller N_M is turned off, the voltage at the primary side of the main transformer is the voltage on the clamp capacitor Cclamp. At this time, the transformer auxiliary drive winding Na3 is coupled to the voltage on the main transformer, and the signal of the same name terminal connection point 501 is negative, and the synchronous rectifier N_rec Shut down. The negative voltage value of 501 is a negative voltage proportional to the voltage of the primary side of the main transformer. The boost diode Dp3 is turned on, and Na3 charges the boost capacitor Cp3. At this time, since Dp3 is turned on, the 502 signal is set. low. The auxiliary power supply module is maintained by the power supply capacitor Cc3. The 502 signal is low, Qr3 is turned off, the 504 signal is set high by Rr32, Qd31 is turned on, the 505 signal is high, and the freewheeling tube N_con is turned on in the main circuit.

Scene 4:

One embodiment of the present disclosure, as shown in FIG. 8, is a clamp mode topology of HIGH SIDE CLAMP in an active clamp forward topology.

When the primary circuit main controller N_M is turned on, the transformer auxiliary drive winding Na4 is coupled to the voltage on the main transformer, and the signal of the same name terminal connection point 601 is a negative voltage proportional to the input voltage, and is driven by the 601 signal directly or after further processing. The secondary circuit of the secondary winding circuit N_con is turned off. The boost diode Dp4 is turned on, and Na4 charges the boost capacitor Cp4. At this time, since Dp4 is turned on, the 602 signal is turned low. The auxiliary power supply module is maintained by the power supply capacitor Cc4. The 602 signal is low, Qr4 is turned off, the 604 signal is set high by Rr42, Qd41 is turned on, the 605 signal is high, and the rectifier N_rec is turned on in the main circuit.

When the primary circuit main controller N_M is turned off, the voltage at the primary side of the main transformer is the voltage on the clamp capacitor Cclamp. At this time, the transformer auxiliary drive winding Na4 is coupled to the voltage on the main transformer, the winding connection point 601 signal is positive, and the 601 signal is directly or through. After the further processing, the secondary circuit freewheeling tube N_con that is driven is turned on. The 602 signal is a superposition of the voltage on the 601 signal and the boost capacitor Cp4. The 602 signal charges Cc4 through the auxiliary power supply diode Dc4, which is an energy source for the auxiliary power supply 603 signal. At the same time, the 602 signal turns on Qr4 through Rr41, sets the 604 signal low, and then the 605 signal goes low, and the synchronous rectifier N_rec in the main loop is turned off.

Scene 5:

One embodiment of the present disclosure, as shown in FIG. 9, is a single-ended forward capacitor resonant reset topology.

When the primary circuit main controller N_M is turned on, the transformer auxiliary drive winding Na5 is coupled to the voltage on the main transformer, and the signal of the same name terminal connection point 701 is a forward voltage proportional to the input voltage, and the 701 signal can be driven directly or after further processing. Circuit synchronous rectifier N_rec. At this time, the 702 signal is a superposition of the voltage on the 701 signal and the boosting capacitor Cp5. The 702 signal is charged to Cc5 by the auxiliary power supply diode Dc5, which is an energy source for the auxiliary power supply 703 signal. At the same time, the 702 signal turns on Qr5 through Rr51, sets the 704 signal low, and then the 705 signal is turned low, and the freewheeling tube N_con in the main circuit is turned off.

When the primary circuit main controller N_M is turned off, the voltage at the primary side of the main transformer is the voltage on the resonant capacitor Cres minus the input voltage. At this time, the transformer auxiliary drive winding Na5 is coupled to the voltage on the main transformer, and the signal of the same name terminal connection point 701 is negative, synchronous. The rectifier N_rec is turned off. The negative voltage value of 701 is a negative voltage proportional to the voltage of the primary side of the main transformer. The boost diode Dp5 is turned on, and Na5 charges the boost capacitor Cp5. At this time, since Dp5 is turned on, the 702 signal is set. low. The auxiliary power supply module is maintained by the power supply capacitor Cc5. 702 signal is low, Qr5 is off, 704 signal is After Rr52 is set high, Qd51 is turned on, the 705 signal is high, and the freewheeling tube N_con is turned on in the main circuit.

Scene 6:

The winding self-driving circuit provided by the present disclosure is suitable for the case where a plurality of switching tubes exist in the secondary circuit, and is also configured to have only one switching tube in the secondary circuit. Referring to the implementation shown in Figure 10, it is a flyback topology.

When the primary circuit main controller N_M is turned on, the transformer auxiliary drive winding Na6 is coupled to the voltage on the main transformer, and the signal of the same name terminal connection point 801 is a forward voltage proportional to the input voltage. At this time, the 802 signal is the 801 signal and the boosting capacitor Cp6. The superposition of the voltage. The 802 signal charges Cc6 through the auxiliary power supply diode Dc6, which is an energy source for the auxiliary power supply 803 signal. At the same time, the 802 signal turns on Qr6 through Rr61, sets the 804 signal low, and then the 805 signal goes low, and the rectifier N_rec in the main circuit is turned off.

When the primary circuit main controller N_M is turned off, the transformer acts as a freewheeling of the inductor, and the body diode of the secondary circuit rectifier N_rec is turned on, and the voltage across the secondary side of the transformer winding is clamped to the output voltage. At this time, the transformer auxiliary drive winding Na6 is coupled. The voltage on the main transformer, the signal of the same name end connection point 801 is negative. The negative voltage of the 801 is a negative voltage proportional to the voltage of the primary side of the main transformer. The boost diode Dp6 is turned on, and the Na6 is charged by the boost capacitor Cp6. At this time, since the Dp6 is turned on, the 802 signal is set. low. The auxiliary power supply module is maintained by the power supply capacitor Cc6. The 802 signal is low, Qr6 is turned off, the 804 signal is set high by Rr62, Qd61 is turned on, the 805 signal is high, and the rectifier N_rec is turned on in the main circuit.

The above is a further detailed description of the embodiments of the present disclosure in connection with the exemplary embodiments, and the exemplary embodiments of the present disclosure are not limited to the description. It is to be understood by those skilled in the art that the present invention may be construed as being limited to the scope of the present disclosure.

Industrial applicability

The winding self-driving circuit provided by the embodiment of the present disclosure can drive the two switching tubes in the secondary circuit through a transformer auxiliary driving winding, which simplifies the transformer winding design and can improve the power supply efficiency.

Claims

A winding self-driving circuit comprising:

Transformer auxiliary drive winding, reverse circuit and power drive circuit;

The transformer auxiliary drive winding couples the voltage of the main transformer in the primary side circuit to obtain a positive and negative alternately converted voltage signal; the output end of the transformer auxiliary drive winding and the first switch tube in the secondary side circuit and the opposite Connected to the input end of the circuit, the output end of the reverse circuit is connected to the input end of the power drive circuit, and the output end of the power drive circuit is connected to the second switch tube in the secondary circuit;

When the transformer auxiliary driving winding output is a positive voltage signal, the first switching transistor is driven, and when the output is a negative voltage signal, the voltage signal is reverse processed by the reverse circuit, and then the power driving circuit is used. Driving the second switch tube.
The winding self-driving circuit of claim 1 wherein said transformer auxiliary drive winding is an auxiliary winding of said main transformer.
The winding self-driving circuit of claim 1 further comprising a boosting circuit and an auxiliary power supply circuit;

An input end and an output end of the booster circuit are respectively connected to an output end of the transformer auxiliary drive winding and the reverse circuit input end; the auxiliary power supply circuit includes a unidirectional charging circuit, and the unidirectional charging circuit The input end is connected to the output end of the boosting circuit, and the output end is connected to the circuit to be powered;

When the booster circuit outputs a positive voltage signal, charging the unidirectional charging circuit while supplying power to the circuit to be powered; and when the boosting circuit outputs a negative voltage signal, the unidirectional charging circuit Powering the circuit to be powered.
The winding self-driving circuit of claim 3, wherein said boosting circuit comprises a boosting capacitor, a boosted unidirectional conduction control device;

One end of the boosting capacitor is connected to an output end of the transformer auxiliary driving winding, and the other end is connected to an output end of the boosting single-conduction control device, and the input end of the step-up single-conducting control device is grounded;

When the transformer auxiliary driving winding output voltage signal is negative, charging the boosting capacitor, the transformer auxiliary driving winding output voltage signal is positive, superimposed with the voltage on the boosting capacitor, and then sent to the An auxiliary power supply circuit and the reverse circuit.
A winding self-driving circuit according to claim 4, wherein said boosting circuit further comprises a boosting resistor adjusting subcircuit connected in parallel with said boosting one-way control device.
The winding self-driving circuit of claim 4, wherein the one-way charging circuit comprises: a power supply unidirectional conduction control device and an auxiliary power supply capacitor, the power supply unidirectional control device input terminal and the boosting single guide The output of the control device is connected; one end of the auxiliary power supply capacitor is connected to the output end of the power supply single-conduction control device, and the other end is grounded.
A winding self-driving circuit according to claim 6, wherein said reverse circuit comprises a conduction speed control resistor, a pull-up resistor and a reverse transistor; and a terminal of said conduction speed control resistor is connected to said boost One-way control a cathode of the device, the other terminal is connected to the base of the reverse transistor; the emitter of the reverse transistor is connected to the ground, the collector is connected to one end of the pull-up resistor, and the other end of the pull-up resistor is auxiliary Power supply connection.
A winding self-driving circuit according to claim 7, wherein said power driving circuit comprises a first power transistor and a second power transistor, a base of said first power transistor being coupled to a base of said second power transistor, and simultaneously Connecting the pull-up resistor; the collector of the first power transistor is connected to the auxiliary power supply; the collector of the second power transistor is connected, the emitter of the first power transistor is respectively connected to the second switch Connected to the emitter of the second power transistor.
The winding self-driving circuit according to any one of claims 1 to 8, wherein the first switching tube is a rectifier tube, the second switching tube is a freewheeling tube; or the first switching tube is a freewheeling a tube, the second switch tube is a rectifier tube.
A switching power supply circuit, comprising:

Primary circuit, secondary circuit, and winding self-driving circuit according to any of claims 1-9;

The primary side circuit is coupled to the secondary side circuit, and the transformer auxiliary driving winding couples a voltage of a main transformer in the primary side circuit to obtain a positive and negative alternating voltage signal; the output of the transformer auxiliary driving winding The end is connected to the first switch tube in the secondary circuit, and the output end of the power drive circuit is connected to the second switch tube in the secondary circuit;

When the transformer auxiliary driving winding output is a positive voltage signal, the first switching transistor is driven, and when the output is a negative voltage signal, the voltage signal is reverse processed by the reverse circuit, and then the power driving circuit is used. Driving the second switch tube.
A winding self-driving circuit control implementation method is applied to a winding self-driving circuit including a transformer auxiliary driving winding, a reverse circuit and a power driving circuit, the method comprising:

Connecting the output of the transformer auxiliary drive winding to the first switch and the reverse circuit input of the secondary circuit, respectively, and connecting the output of the reverse circuit to the input of the power drive circuit, and driving the power The output end of the circuit is connected to the second switch tube in the secondary circuit;

The transformer auxiliary driving winding couples the voltage of the main transformer in the primary side circuit to obtain a positive and negative alternating voltage signal;

Driving the first switch tube by the transformer auxiliary drive winding output as a positive voltage signal;

The second switching transistor is driven by the power driving circuit by performing a reverse processing on the voltage signal of the transformer auxiliary driving winding output by the reverse circuit.