CN213817324U

CN213817324U - Power adapter circuit

Info

Publication number: CN213817324U
Application number: CN202022188858.9U
Authority: CN
Inventors: 许志恒
Original assignee: Shenzhen Delippo Technology Co ltd
Current assignee: Shenzhen Delippo Technology Co ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2021-07-27
Anticipated expiration: 2030-09-29

Abstract

The utility model discloses a power adapter circuit, which comprises an input end, two output ports, a rectifying and filtering module, a transformer, a charging control module, a synchronous rectifying module and an intelligent identification module, wherein the rectifying and filtering module rectifies and filters alternating current input by a voltage input end and outputs the rectified alternating current to the primary side of the transformer, the charging control module identifies the voltage waveform of the alternating current to control the on-off state of the transformer, the transformer induces voltage and current to the synchronous rectifying module, the synchronous rectifying module converts the voltage and current output by the transformer into direct current voltage and direct current, when the intelligent identification module identifies that the voltage output port is connected with a terminal to be charged, the corresponding voltage output port outputs charging voltage and charging current, the waveform of the alternating current is identified by the charging control module, and the output charging voltage and the charging battery are adjusted in real time by adjusting the conduction degree of the transformer in real time, therefore, the conversion efficiency of the power adapter is improved, and the power consumption is greatly reduced.

Description

Power adapter circuit

Technical Field

The utility model relates to a power adapter, in particular to power adapter circuit.

Background

The Power adapter (Power adapter) is a Power supply conversion device for small portable electronic equipment and electronic appliances, and is applied to various voltage conversion scenes. A control circuit is typically included in the power adapter for controlling the switching of the switching circuit of the primary circuit in the power adapter. The control circuit may be, for example, a Pulse Width Modulation (PWM) controller.

With the popularity of the rapid charging protocol, more and more power adapters support a wide range of outputs from multiple power sources. For example, a Quick Charge Protocol (QCP) supports an output voltage of 3.6V to 12V, a Universal Serial Bus (USB) -power transmission specification (PDS) supports an output voltage of 5V to 12V, and an intelligent charge protocol (SCP) supports an output voltage of 3.4V to 12V.

However, since the supply voltage of the control circuit is usually provided by the auxiliary power supply, and the auxiliary power supply is usually flyback-powered, the voltage provided by the auxiliary power supply is usually in direct proportion to the output voltage of the secondary side circuit, and when the voltage output by the power adapter is high, the supply voltage provided by the auxiliary power supply for the control circuit is also higher than the operating voltage required by the control circuit, which results in increased power consumption of the auxiliary power supply and low conversion efficiency.

Thus, the prior art has yet to be improved and enhanced.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing disadvantages of the prior art, an object of the present invention is to provide a power adapter circuit, which can reduce the power consumption of the power adapter and improve the conversion efficiency.

For solving the technical problem, the utility model discloses following technical scheme has been taken:

a power adapter circuit comprises a voltage input end, a first voltage output port, a second voltage output port, a rectifying and filtering module, a transformer, a charging control module, a synchronous rectifying module and an intelligent identification module, the rectification filter module rectifies and filters the alternating current input by the voltage input end and outputs the alternating current to a first primary winding of the transformer, the charging control module recognizes a voltage waveform of the alternating current to control a switching state of the transformer, the transformer outputs corresponding voltage and current to the synchronous rectification module, the synchronous rectification module converts the voltage and current output by the transformer into direct current voltage and direct current and outputs the direct current voltage and direct current to the intelligent identification module, and when the intelligent identification module identifies that the first voltage output port and/or the second voltage output port are connected with the terminal to be charged, the corresponding voltage output ports output charging voltage and charging current.

As the utility model discloses an improvement, the power adapter circuit still includes power module, power module connects the second primary winding and the charging control module of transformer, for charging control module and transformer power supply.

As the utility model discloses an improve, state the control module that charges and include waveform detection unit, opto-coupler feedback unit, PWM the control unit and switch unit, opto-coupler feedback unit and intelligent recognition module communication feed back PWM the control unit with the communication result, PWM the control unit is according to the PWM switch signal of the corresponding duty cycle of voltage waveform output that waveform detection unit detected, the on-state of control switch unit.

As a further improvement, the synchronous rectification module includes synchronous rectification unit, synchronous rectification step-down unit and first filtering unit, the voltage and the current conversion of synchronous rectification unit secondary output of transformer are DC voltage and direct current to carry out rectification and step-down by synchronous rectification step-down unit and handle for waiting that charging terminal charges required charging voltage and charging current, first filtering unit is with the DC voltage and the direct current filtering of synchronous rectification step-down unit output and supply power for the intelligent recognition module after handling.

As the utility model discloses further improvement, the intelligent recognition module includes that intelligent recognition unit and PD fill the unit soon, the output that first voltage delivery outlet and PD fill the unit soon is adjusted in real time to the charged state of first voltage delivery outlet of intelligent recognition unit discernment or second voltage delivery outlet.

As a further improvement of the utility model, the rectification filter module includes second filtering unit, preliminary rectification unit and RCD absorption unit, and after the peak thorn voltage, electric current were got rid of in the second filtering unit filtering to the alternating current, through preliminary rectification unit rectification filtering to get rid of the first primary winding of exporting to the transformer after EMI interference through RCD absorption unit.

As a further improvement of the utility model, the PWM control unit includes PWM management chip, first resistance, second resistance, third resistance, fourth resistance, first diode, first electric capacity, second electric capacity and third electric capacity, the FMAX end of PWM management chip is through first resistance ground connection, and opto-coupler feedback unit, also through first electric capacity ground connection are connected to the FB end of PWM management chip, and the ZCD end of PWM management chip connects the negative pole of first diode, also through the one end of second resistance connection third resistance and the positive pole of first diode, still through fourth resistance ground connection, the second primary winding and the power module of transformer are connected to the other end of third resistance, and the CS end and the DVR end switch unit of PWM management chip, the second electric capacity is parallelly connected with fourth resistance.

As the utility model discloses further improvement again, the switch unit includes switch chip, fifth resistance, sixth resistance and seventh resistance, switch chip ' S GATE end through fifth resistance connection PWM manage the DVR end of chip, also through sixth resistance ground connection, switch chip ' S S end through seventh resistance connection PWM manage the CS end of chip, switch chip ' S DF end is connected rectification filtering module.

As a further improvement of the present invention, the synchronous rectification unit includes a synchronous rectification controller, an MOS chip, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, and a seventh capacitor, the CAP end of the synchronous rectification controller is grounded through the fourth capacitor, the XV end of the synchronous rectification controller is grounded through the fifth capacitor, and is further connected to the one end of the synchronous rectification voltage-reduction unit and the sixth capacitor through the eighth resistor, and the other end of the sixth capacitor is grounded, the Source end and the GATE end of the synchronous rectification controller are respectively connected to the G end of the MOS chip through the ninth resistor and the tenth resistor, the Drain end of the synchronous rectification controller is connected to the D end of the MOS chip and the one end of the seventh capacitor through the eleventh resistor, and the other end of the seventh capacitor is connected to the G end of the MOS chip through the twelfth resistor and the twelfth resistor, And the thirteenth resistor is connected with the S end of the MOS chip and the first filtering unit.

As the utility model discloses further improvement again, the intelligent recognition unit includes intelligent recognition chip, fourteenth resistance, ninth electric capacity and tenth electric capacity, synchronous rectification step-down unit, also through ninth electric capacity ground connection are connected to the Vin end of intelligent recognition chip, and the Stat end of intelligent recognition chip fills the unit soon through fourteenth resistance connection PD, the power foot of first voltage delivery outlet is connected to the Vout end of intelligent recognition chip, and the DM foot of first voltage delivery outlet is connected to the DM end of intelligent recognition chip, and the DP foot of first voltage delivery outlet is connected to the DP end of intelligent recognition chip.

Compared with the prior art, the utility model provides a power adapter circuit, including voltage input end, first voltage delivery outlet, second voltage delivery outlet, rectification filter module, transformer, charging control module, synchronous rectifier module and intelligent identification module, rectification filter module rectifies and filters the alternating current of voltage input end input and exports the first primary winding for the transformer after handling, charging control module discerns the voltage wave form of alternating current and controls the on-off state of transformer, and exports corresponding voltage and electric current to synchronous rectifier module by the transformer, synchronous rectifier module converts the voltage and electric current of transformer output into direct current voltage and direct current and exports to intelligent identification module, when intelligent identification module discerns first voltage delivery outlet and/or second voltage delivery outlet and connects the terminal of waiting to charge, make corresponding voltage outlet output charging voltage and charging current, through the wave form of charging control module discernment alternating current, adjust the conduction degree of transformer in real time and adjust the charging voltage and the rechargeable battery of output to improve power adapter's conversion efficiency, the consumption also reduces by a wide margin moreover, and power adapter generates heat fewly.

Drawings

Fig. 1 is a schematic structural diagram of a power adapter provided by the present invention.

Fig. 2 is a circuit block diagram of the power adapter provided by the present invention.

Fig. 3 is a schematic diagram of a schematic circuit of a portion of the power adapter circuit provided by the present invention.

Fig. 4 is the circuit schematic diagram of the PD quick charging unit and the second voltage output port in the power adapter circuit provided by the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "on," "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present.

It should be noted that the terms of orientation such as left, right, up and down in the embodiments of the present invention are only relative to each other or are referred to the normal use state of the product, and should not be considered as limiting.

Referring to fig. 1, the power adapter has a power plug and a voltage output port (usually a USB port), the power plug is connected to an alternating current, and the voltage conversion process is performed by a power adapter circuit inside the power adapter body, so that the voltage output port outputs a corresponding direct current voltage and current to charge the electronic product.

Please refer to fig. 2 and fig. 3, the utility model provides a power adapter circuit, including voltage input AC, first voltage delivery outlet J1, second voltage delivery outlet J2, rectification filter module 10, transformer T1, charging control module 20, synchronous rectification module 30 and intelligent recognition module 40, voltage input AC, rectification filter module 10, transformer T1's first primary winding, transformer T1's secondary winding, synchronous rectification module 30, intelligent recognition module 40 connect gradually, charging control module 20 connects transformer T1's first primary winding, first voltage delivery outlet J1 and second voltage delivery outlet J2 are connected to the output of intelligent recognition module 40.

The rectifying and filtering module 10 rectifies and filters alternating current input by a voltage input end AC and outputs the rectified and filtered alternating current to a first primary winding of a transformer T1, the charging control module 20 identifies the voltage waveform of the alternating current to control the switching state of the transformer T1, and outputs corresponding voltage and current to the synchronous rectifying module 30 through the transformer T1, the synchronous rectifying module 30 converts the voltage and current output by the transformer T1 into direct current voltage and direct current to output the direct current to the intelligent identification module 40, and when the intelligent identification module 40 identifies that the first voltage output port J1 and/or the second voltage output port J2 are/is connected with a terminal to be charged, the corresponding voltage output port outputs charging voltage and charging current. The utility model discloses a charge control module 20 discerns the wave form of alternating current, and the conduction degree of real-time regulating transformer T1 comes real-time regulation output's charging voltage and rechargeable battery to improve power adapter's conversion efficiency, the consumption also reduces by a wide margin moreover, and power adapter generates heat fewly.

With continued reference to fig. 2 and 3, the power adapter circuit further includes a power supply module 50, and the power supply module 50 is connected to the second primary winding of the transformer T1 and the charging control module 20 to supply power to the charging control module 20 and the transformer T1.

Referring to fig. 4, the charging control module 20 includes a waveform detection unit 201, an optical coupler feedback unit 202, a PWM control unit 203, and a switch unit 204, one end of the waveform detection unit 201 is connected to the rectifying and filtering module 10, the other end of the waveform detection unit 201 is connected to the optical coupler feedback unit 202 and the synchronous rectifying module 30, an input end of the optical coupler feedback unit 202 is connected to the intelligent recognition module 40, and communicates with the intelligent recognition module 40, and a feedback end of the optical coupler feedback unit 202 is connected to the first primary winding of the transformer T1 sequentially through the PWM control unit 203 and the switch unit 204.

The waveform detection unit 201 may use capacitance detection to obtain the voltage waveform of the alternating current through a capacitor charging and discharging cycle. The optocoupler feedback unit communicates with the intelligent identification module 40 through a PD protocol, and feeds back the optocoupler feedback unit to the PWM control unit 203 when the communication is successful, the PWM control unit 203 outputs a PWM switching signal with a corresponding duty ratio according to the voltage waveform detected by the waveform detection unit 201, and controls the conduction state of the switching unit 204, i.e., the conduction degree of the switching unit 204, so as to improve the power conversion efficiency.

Referring to fig. 3, the synchronous rectification module 30 includes a synchronous rectification unit 301, a synchronous rectification step-down unit 302 and a first filtering unit 303, the input end of the synchronous rectification unit 301 is connected to the secondary winding of the transformer T1 for converting the voltage and current output from the secondary winding of the transformer T1 into dc voltage and dc current, the output end of the synchronous rectification unit 301 is connected to the intelligent identification module 40 through the synchronous rectification step-down unit 302 and is also connected to the intelligent identification module 40 through the first filtering unit 303, the synchronous rectification step-down unit 302 rectifies and steps down the charging voltage and charging current required for charging the terminal to be charged and outputs the charging voltage and charging current to the intelligent identification module 40, the intelligent identification module 40 outputs the corresponding charging voltage and charging current to the voltage output port according to the state of the terminal to be charged connected to the voltage output port, and the synchronous rectification unit 301 is filtered by the first filtering unit 303, power is supplied to smart identification module 40.

The intelligent identification module 40 comprises an intelligent identification unit 401 and a PD quick-charging unit 402, wherein the intelligent identification unit 401 identifies the charging state of the first voltage output port J1 or the second voltage output port J2, adjusts the output power of the first voltage output port J1 and the PD quick-charging unit 402 in real time, and finally enables the first voltage output port J1 and the second voltage output port J2 to output corresponding charging voltage and charging current according to the type of a charging terminal.

With reference to fig. 3, the rectifying and filtering module includes a second filtering unit 101, a preliminary rectifying unit 102, and an RCD absorbing unit 103, where the voltage input terminal AC, the second filtering unit 101, the preliminary rectifying unit 102, the RCD absorbing unit 103, and the first primary winding of the transformer T1 are connected in sequence.

After the ac power is filtered by the second filtering unit 101 to remove the peak spike voltage and the current, the ac power is rectified and filtered by the primary rectifying unit 102, and is output to the first primary winding of the transformer T1 after the EMI interference is removed by the RCD absorbing unit 103.

Referring to fig. 3 and 4, the PWM control unit 203 includes a PWM management chip U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D1, a first capacitor C1, a second capacitor C2, and a third capacitor C3, the FMAX end of the PWM management chip U1 is grounded through a first resistor R1, the FB end of the PWM management chip U1 is connected with the optocoupler feedback unit 202 and is also grounded through a first capacitor C1, the ZCD end of the PWM management chip U1 is connected with the cathode of a first diode D1, one end of a third resistor R3 and the anode of the first diode D1 are also connected through a second resistor R2, and the ZCD end of the PWM management chip U1 is also grounded through a fourth resistor R4, the other end of the third resistor R3 is connected to the second primary winding of the transformer T1 and the power supply module 50, the CS terminal and the DVR terminal of the PWM management chip U1 are connected to the switching unit 204, the second capacitor C2 is connected in parallel with the fourth resistor R4, and the HV end of the PWM management chip U1 is connected with the dotted terminal of the first primary winding of the transformer T1 through a resistor.

Because PD fills unit 402 soon and second voltage output port J2 sets up on a little circuit board, the utility model discloses an opto-coupler feedback unit 202 makes PD fill unit 402 soon and establish the communication with the mainboard (the circuit board that PWM management chip place promptly).

In this embodiment, the PWM management chip U1 may adopt a chip of the model NCP1342 or other chips with the same function, and the PWM management chip U1 controls the opening degree of the switching unit 204 according to the voltage waveform of the alternating current, and adjusts the PWM duty ratio of the driving signal DVR in real time according to the current fed back by the switching unit 204, and finally adjusts the output power of the transformer T1.

With reference to fig. 3 and fig. 4, the switch unit 204 includes a switch chip U2, a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7, the GATE terminal of the switch chip U2 is connected to the DVR terminal of the PWM management chip U1 through the fifth resistor R5 and is also connected to the ground through the sixth resistor R6, the S terminal of the switch chip U2 is connected to the CS terminal of the PWM management chip U1 through the seventh resistor R7, and the DF terminal of the switch chip U2 is connected to the rectifying and filtering module.

The switch chip U2 may be a switch chip U2 or other chips with the same function, and after the GATE terminal of the switch chip U2 receives the driving signal, the DF terminal outputs a current to the synonym terminal of the first primary winding of the transformer T1, so that the transformer T1 operates.

The synchronous rectification unit 301 includes a synchronous rectification controller U3, an MOS chip U4, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, and a seventh capacitor C7, the CAP end of the synchronous rectification controller U3 is grounded through the fourth capacitor C3, the XV end of the synchronous rectification controller U3 is grounded through the fifth capacitor C3, and is further connected to one end of the synchronous rectification voltage-reducing unit 302 and the sixth capacitor C3 through the eighth resistor R3, the other end of the sixth capacitor C3 is grounded, the Source end and the GATE end of the synchronous rectification controller U3 are connected to the G end of the MOS chip U3 through the ninth resistor R3, the tenth resistor R3, the Drain end of the synchronous rectification controller U3 is connected to the twelfth end of the MOS chip C3 through the twelfth resistor R3, and the seventh capacitor C3, and the other end of the seventh capacitor C3 are connected to the MOS chip C3 through the twelfth resistor R3, and the Drain end of the Drain resistor R3, respectively, The thirteenth resistor R13 connects the S terminal of the MOS chip U4 and the first filtering unit.

The synchronous rectification controller U3 may adopt a chip of model TEA1993, the synchronous rectification voltage-reduction unit 302 includes a rectification voltage-reduction chip and a plurality of peripheral electronic devices such as resistors and capacitors, and the rectification voltage-reduction chip may adopt an integrated chip of model TM 12286. The voltage and current output by the transformer T1 are synchronously rectified by the synchronous rectification controller U3 and peripheral elements thereof to output 19V direct current, and then rectified and stepped down by the rectification step-down chip to 5V2A to supply power to the intelligent identification unit 401.

The intelligent identification unit 401 comprises an intelligent identification chip U5, a fourteenth resistor R14, a ninth capacitor C9 and a tenth capacitor C10, wherein the Vin end of the intelligent identification chip U5 is connected with the synchronous rectification voltage reduction unit 302 and is grounded through a ninth capacitor C9, the Stat end of the intelligent identification chip U5 is connected with the PD quick charging unit 402 through a fourteenth resistor R14, the Vout end of the intelligent identification chip U5 is connected with the power supply pin of the first voltage output port J1 and is grounded through a tenth capacitor C10, the DM end of the intelligent identification chip U5 is connected with the DM pin of the first voltage output port J1, and the DP end of the intelligent identification chip U5 is connected with the DP pin of the first voltage output port J1.

The intelligent identification chip U5 is an integrated chip with the model number of HUSB304 or other chips with the same function. The intelligent identification chip U5 can directly output 5V voltage to the first voltage output port J1 for external power supply, the output power of the intelligent identification chip can reach 30W, the conversion efficiency is high, and the charging speed is high. The HUSB304 chip combines the MOS chip U4, and whether discernment electronic equipment removed, whether the circuit short circuit, still have input undervoltage, overvoltage protection, short-circuit protection, overcurrent protection, thermal shutdown etc.. The charging state of specific electronic equipment (such as a notebook computer, a mobile phone, a tablet and the like), such as the charging current, adjusts the output power of a voltage output port in real time, thereby realizing quick charging, avoiding the heating of a power adapter and improving the conversion efficiency of the power adapter.

In this embodiment, the first voltage output port J1 is a USB port, the second voltage output port J2 is a TypeC port, the synonym terminal of the secondary winding of the transformer T1 is connected to the PD fast charging unit 402 via the first filtering unit, and the PD fast charging unit 402 includes a HUSB350-QFN16 fast charging chip, an AP4453G MOS chip, and peripheral electronic devices thereof.

The CATH end of the quick charging chip is connected with the optical coupling feedback unit 202, it is reliable to ensure that two circuit boards are electrically connected with the communication of the optical coupling feedback unit 202, the Stat end of the intelligent identification chip U5 is connected with the GPIOB end of the quick charging chip, the Type port is given by the output 18W power of the intelligent identification chip U5, the quick charging of the electronic terminal connected with the quick charging chip is enabled, the USB port is given by the output 30W power, finally, the electronic equipment is charged by the maximum power according to the Type of the electronic equipment, and the power conversion efficiency is improved. In this practical example, first voltage output port J1, second voltage output port J2 can charge simultaneously, also can externally charge by one, the utility model discloses do not do the restriction to this.

To sum up, the utility model discloses a charge control module discerns the wave form of alternating current, and the conduction degree of real-time regulation transformer comes real-time regulation output's charging voltage and rechargeable battery to improve power adapter's conversion efficiency, the consumption also reduces by a wide margin moreover, and power adapter generates heat fewly.

It should be understood that equivalent alterations and modifications can be made by those skilled in the art according to the technical solution of the present invention and the inventive concept thereof, and all such alterations and modifications should fall within the scope of the appended claims.

Claims

1. A power adapter circuit includes a voltage input terminal, a first voltage output port, and a second voltage output port, it is characterized by also comprising a rectifying and filtering module, a transformer, a charging control module, a synchronous rectifying module and an intelligent identification module, the rectification filter module rectifies and filters the alternating current input by the voltage input end and outputs the alternating current to a first primary winding of the transformer, the charging control module recognizes a voltage waveform of the alternating current to control a switching state of the transformer, the transformer outputs corresponding voltage and current to the synchronous rectification module, the synchronous rectification module converts the voltage and current output by the transformer into direct current voltage and direct current and outputs the direct current voltage and direct current to the intelligent identification module, and when the intelligent identification module identifies that the first voltage output port and/or the second voltage output port are connected with the terminal to be charged, the corresponding voltage output ports output charging voltage and charging current.

2. The power adapter circuit of claim 1, further comprising a power module connecting the second primary winding of the transformer and the charging control module to power the charging control module and the transformer.

3. The power adapter circuit of claim 2, wherein the charging control module comprises a waveform detection unit, an optocoupler feedback unit, a PWM control unit and a switch unit, the optocoupler feedback unit communicates with the intelligent identification module and feeds back a communication result to the PWM control unit, and the PWM control unit outputs a PWM switch signal with a corresponding duty ratio according to a voltage waveform detected by the waveform detection unit to control a conduction state of the switch unit.

4. The power adapter circuit of claim 1, wherein the synchronous rectification module comprises a synchronous rectification unit, a synchronous rectification voltage reduction unit and a first filtering unit, the synchronous rectification unit converts the voltage and the current output by the secondary side of the transformer into a direct current voltage and a direct current, the synchronous rectification voltage reduction unit performs rectification and voltage reduction processing on the direct current voltage and the direct current to charge the terminal to be charged, and the first filtering unit filters the direct current voltage and the direct current output by the synchronous rectification voltage reduction unit and supplies power to the intelligent identification module.

5. The power adapter circuit of claim 4, wherein the smart identification module comprises a smart identification unit and a PD quick charging unit, and the smart identification unit identifies the charging state of the first voltage output port or the second voltage output port and adjusts the output power of the first voltage output port and the PD quick charging unit in real time.

6. The power adapter circuit of claim 1, wherein the rectifying and filtering module comprises a second filtering unit, a preliminary rectifying unit and an RCD absorbing unit, and the ac power is filtered by the second filtering unit to remove the peak spike voltage and current, rectified and filtered by the preliminary rectifying unit, and output to the first primary winding of the transformer after the EMI interference is removed by the RCD absorbing unit.

7. The power adapter circuit of claim 3, wherein the PWM control unit comprises a PWM management chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, a first capacitor, a second capacitor and a third capacitor, the FMAX terminal of the PWM management chip is grounded through the first resistor, the FB terminal of the PWM management chip is connected with the optocoupler feedback unit and is also grounded through the first capacitor, the ZCD terminal of the PWM management chip is connected with the cathode of the first diode, one end of the third resistor and the anode of the first diode are also connected through the second resistor, and is also grounded through the fourth resistor, the other end of the third resistor is connected with the second primary winding of the transformer and the power supply module, the CS terminal and the DVR terminal of the PWM management chip are connected with the switch unit, and the second capacitor is connected with the fourth resistor in parallel.

8. The power adapter circuit of claim 7, wherein the switch unit includes a switch chip, a fifth resistor, a sixth resistor and a seventh resistor, the GATE terminal of the switch chip is connected to the DVR terminal of the PWM management chip through the fifth resistor and is also connected to the ground through the sixth resistor, the S terminal of the switch chip is connected to the CS terminal of the PWM management chip through the seventh resistor, and the DF terminal of the switch chip is connected to the rectifying and filtering module.

9. The power adapter circuit according to claim 4, wherein the synchronous rectification unit comprises a synchronous rectification controller, an MOS chip, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor, the CAP end of the synchronous rectification controller is grounded through the fourth capacitor, the XV end of the synchronous rectification controller is grounded through the fifth capacitor and is further connected with one end of the synchronous rectification voltage reduction unit and one end of the sixth capacitor through the eighth resistor, the other end of the sixth capacitor is grounded, the Source end and the GATE end of the synchronous rectification controller are respectively connected with the G end of the MOS chip through the ninth resistor and the tenth resistor, the Drain end of the synchronous rectification controller is connected with the D end of the MOS chip and one end of the seventh capacitor through the eleventh resistor, and the other end of the seventh capacitor is respectively connected with the G end of the MOS chip through the twelfth resistor, the eleventh resistor, the sixth capacitor, the eighth capacitor, the sixth capacitor, and the sixth capacitor, the sixth resistor, the sixth capacitor, the sixth resistor, the sixth capacitor, the sixth resistor, the sixth capacitor, and the thirteenth resistor is connected with the S end of the MOS chip and the first filtering unit.

10. The power adapter circuit of claim 9, wherein the smart identification unit comprises a smart identification chip, a fourteenth resistor, a ninth capacitor and a tenth capacitor, the Vin terminal of the smart identification chip is connected to the synchronous rectification voltage reduction unit and also grounded via the ninth capacitor, the Stat terminal of the smart identification chip is connected to the PD quick charging unit via the fourteenth resistor, the Vout terminal of the smart identification chip is connected to the power pin of the first voltage output port and also grounded via the tenth capacitor C10, the DM terminal of the smart identification chip is connected to the DM pin of the first voltage output port, and the DP terminal of the smart identification chip is connected to the DP pin of the first voltage output port.