Charger circuit

Abstract

The utility model provides a charger circuit comprising a voltage conversion unit suitable for converting the type and amplitude of a power supply voltage and generating a conversion voltage to a voltage transformation unit and a compensation unit; the voltage transformation unit comprises a transformer, the transformer comprises a primary winding, a secondary winding and an auxiliary winding, the first end of the primary winding is coupled with the voltage conversion unit, and the second end of the primary winding is coupled with the compensation unit; the first end of the auxiliary winding serves as a feedback node; an output node of the secondary winding is coupled with the charging protocol unit and outputs the transformation voltage to the charging protocol unit; and the compensation unit is suitable for responding to the divided voltage, is in a gated state, changes the feedback amplitude of the feedback end according to the voltage change of the feedback node, and generates a corresponding compensation voltage to the second end of the primary winding so as to change the transformation voltage. By adopting the technical scheme, the consistency of the terminal voltage of the electronic equipment during light load and heavy load can be improved.

Description

Technical Field

[0001] This utility model relates to the field of charging technology, and in particular to a charger circuit. Background Technology

[0002] In recent years, with the rapid development of technology, electronic devices have become indispensable tools in people's daily lives. During use, electronic devices typically require a power source, and chargers are one such tool. Chargers provide a stable power supply to electronic devices by transferring current into them, thus enabling them to be charged.

[0003] In practical applications, when the load on the electronic device changes and the charging cable is too long, the voltage on the electronic device will change. Utility Model Content

[0004] In view of this, the present invention provides a charger circuit that can improve the consistency of the terminal voltage of electronic devices under light and heavy loads.

[0005] This utility model provides a charger circuit, including: a voltage conversion unit, a transformer unit, a compensation unit, and a charging protocol unit, wherein:

[0006] The voltage conversion unit is adapted to convert the type and amplitude of the power supply voltage and generate a converted voltage to the transformer unit and the compensation unit;

[0007] The transformer unit includes a transformer, which includes a primary winding, a secondary winding, and an auxiliary winding. The first end of the primary winding is coupled to the voltage conversion unit, and the second end of the primary winding is coupled to the compensation unit. The first end of the auxiliary winding serves as a feedback node. The output node of the secondary winding is coupled to the charging protocol unit, and outputs a transformer voltage to the charging protocol unit.

[0008] The compensation unit is adapted to be in a selected state in response to the conversion voltage, and to change the feedback amplitude of the feedback terminal according to the voltage change of the feedback node, thereby generating a corresponding compensation voltage to the second terminal of the primary winding to change the transformer voltage; wherein the voltage change of the feedback node is determined according to the output current of the charging protocol unit.

[0009] Optionally, the compensation unit includes: a control chip, a first feedback branch, and a second feedback branch, wherein:

[0010] The enable terminal of the control chip is adapted to receive the conversion voltage, and the output terminal is coupled to the second end of the primary winding.

[0011] The first feedback branch is connected to the first end of the auxiliary winding and the second feedback branch, respectively.

[0012] The second feedback branch is coupled to the first end of the auxiliary winding and is adapted to be in a selected or disconnected state in response to the voltage change of the feedback node.

[0013] Specifically, when the second feedback branch is in the selected state, the feedback terminal of the control chip is the first feedback amplitude, so that the transformer voltage remains unchanged; when the second feedback branch is in the open state, the feedback terminal of the control chip is the second feedback amplitude, the transformer voltage increases, and the first feedback amplitude and the second feedback amplitude are different.

[0014] Optionally, the second feedback branch includes: a selection transistor, a selection resistor, a first diode, and a parallel voltage regulator, wherein:

[0015] The control terminal of the selection transistor is coupled to the first terminal of the first diode and the parallel voltage regulator, respectively. The first terminal of the selection transistor is coupled to the feedback node. The second terminal of the selection transistor is coupled to the feedback terminal of the control chip through the selection resistor.

[0016] The second terminal of the first diode is coupled to the parallel voltage regulator;

[0017] The parallel voltage regulator includes: a first voltage-regulating resistor, a second voltage-regulating resistor, a first voltage-dividing resistor, a second voltage-dividing resistor, and a Zener transistor. The first terminal of the first voltage-regulating resistor is coupled to the first terminal of the first diode and the control terminal of the selector transistor. The second terminal of the first voltage-regulating resistor is coupled to the first terminal of the second voltage-regulating resistor and the first terminal of the first voltage-dividing resistor, and is connected to the feedback voltage. The second terminal of the second voltage-regulating resistor is coupled to the second terminal of the Zener transistor and the second terminal of the first diode. The second terminal of the first voltage-dividing resistor is coupled to the first terminal of the second voltage-dividing resistor and the control terminal of the Zener transistor. The first terminal of the Zener transistor is coupled to the second terminal of the second voltage-dividing resistor and connected in parallel to a first ground.

[0018] Optionally, the first feedback branch includes: a first feedback resistor, a second feedback resistor, a third feedback resistor, and a feedback capacitor, wherein: the first end of the first feedback resistor is coupled to the feedback node, and the second end of the first feedback resistor is coupled to the second feedback resistor, the third feedback resistor, the feedback capacitor, and the feedback terminal respectively; the second ends of the second feedback resistor, the third feedback resistor, and the feedback capacitor are all connected to a first ground.

[0019] Optionally, the charger circuit also includes at least one or more of the following:

[0020] The voltage divider unit is coupled to the enable terminal of the voltage conversion unit and the compensation unit, and is adapted to divide the converted voltage output by the voltage conversion unit to obtain the divided voltage.

[0021] An absorption unit, coupled to the output terminal of the compensation unit, is adapted to absorb the spike voltage at the output terminal of the compensation unit when the second feedback branch is in an open state.

[0022] Optionally, the voltage divider unit includes a third voltage divider resistor and a fourth voltage divider resistor, wherein the first end of the third voltage divider resistor is coupled to the voltage conversion unit and the first end of the primary winding, respectively, and the second end of the third voltage divider resistor is coupled to the fourth voltage divider resistor; the second end of the fourth voltage divider resistor is coupled to the enable terminal of the compensation unit.

[0023] The absorption unit includes: a first absorption resistor, a second absorption resistor, a third absorption resistor, a second diode, and an absorption capacitor. The first end of the first absorption resistor is coupled to the output end of the compensation unit, and the second end of the first absorption resistor is coupled to the first end of the second diode. The second end of the second diode is coupled to the second ends of the second absorption resistor, the third absorption resistor, and the absorption capacitor, respectively. The first ends of the second absorption resistor, the third absorption resistor, and the absorption capacitor are coupled to each other.

[0024] Optionally, the voltage conversion unit includes: a first filtering module, a rectifier module, and a second filtering module, wherein: the first filtering module is coupled to the rectifier module and is adapted to receive the power supply voltage; the rectifier module is coupled to the second filtering module and is adapted to convert the type of power supply voltage; and the second filtering module is coupled to the first end of the primary winding.

[0025] Optionally, the voltage conversion unit satisfies at least one or more of the following:

[0026] The first filtering module includes a common-mode inductor, wherein the first and second ends of the common-mode inductor are adapted to receive the supply voltage, and the third and fourth ends of the common-mode inductor are coupled to the rectifier module.

[0027] The rectifier module includes: a full-bridge rectifier circuit composed of diodes;

[0028] The second filtering module includes: a first filtering capacitor, a second filtering capacitor, a third filtering capacitor, and a filtering inductor, wherein the first terminal of the first filtering capacitor is connected to the first terminal of the filtering inductor, and the second terminals of the first filtering capacitor, the second filtering capacitor, and the third filtering capacitor are coupled together and connected to a first ground; the second terminal of the filtering inductor is coupled to the first terminals of the second filtering capacitor and the third filtering capacitor, respectively.

[0029] Optionally, the charging protocol unit includes multiple charging protocol modules, each of which includes a matching charging protocol IC and a USB port, wherein the charging protocol IC is coupled to the output node and the corresponding USB port respectively.

[0030] Optionally, the charger circuit further includes: an output module disposed between the output node and the charging protocol unit, wherein the output module includes:

[0031] The circuit includes a rectifier and filter branch consisting of a first electrolytic capacitor and a second electrolytic capacitor, and a relay branch consisting of a relay resistor, a relay capacitor, and a relay. The first terminals of both the first and second electrolytic capacitors are coupled to the first terminal of the secondary winding and serve as the output node. The second terminals of both the first and second electrolytic capacitors are connected to a second ground and are coupled to the second terminals of the relay and the relay capacitor. The first terminals of the relay resistor and the relay are coupled to the second terminal of the secondary winding, and the second terminal of the relay resistor is coupled to the first terminal of the relay capacitor.

[0032] Compared with the prior art, the technical solution of this utility model embodiment has the following advantages:

[0033] The charger circuit provided in this utility model embodiment includes a charging protocol unit connected to an electronic device. When the load on the electronic device changes, the output current of the charging protocol unit changes. The charging protocol unit is coupled to the output node of the secondary winding, and based on the transformer's voltage transformation principle, the voltage at the feedback node changes. In response to this change, the compensation unit can change the feedback amplitude at the feedback terminal, thereby generating a corresponding compensation voltage at the second terminal of the primary winding. Thus, when the charging voltage generated by the voltage conversion unit remains constant, the voltage drop across the primary winding can be changed, thereby changing the transformer voltage. This compensates for the change and achieves voltage consistency at the electronic device under light and heavy loads. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] Figure 1 A schematic diagram of a charger circuit according to an embodiment of the present invention is shown;

[0036] Figure 2A schematic diagram of a charging protocol unit according to an embodiment of the present invention is shown;

[0037] Figure 3 A schematic diagram of the specific structure of a charger circuit according to one embodiment of the present invention is shown. Detailed Implementation

[0038] As described in the background section, when the load on the electronic device changes and the charging cable is too long, the voltage on the electronic device will change.

[0039] To address the aforementioned technical problems, this utility model provides a charger circuit. A charging protocol unit is connected to an electronic device. When the load on the electronic device changes, the output current of the charging protocol unit changes. The charging protocol unit is coupled to the output node of the secondary winding. Based on the transformer's voltage transformation principle, this causes a change in the voltage at the feedback node. In response to this change, the compensation unit can alter the feedback amplitude at the feedback terminal, thereby generating a corresponding compensation voltage at the second terminal of the primary winding. Thus, when the charging voltage generated by the voltage conversion unit remains constant, the voltage drop across the primary winding can be changed, thereby altering the transformer voltage. This compensates for the change and achieves voltage consistency at the electronic device under both light and heavy loads.

[0040] To enable those skilled in the art to better understand and implement this disclosure, the following detailed description of the specific solutions, principles, advantages, and effects of this disclosure is provided with reference to the accompanying drawings and specific embodiments.

[0041] See Figure 1 and Figure 2 ,in, Figure 1 This is a schematic diagram of a charger circuit according to one embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a charging protocol unit in one embodiment of the present invention, as shown below. Figure 1 and Figure 2 As shown, the charger circuit may include: a voltage conversion unit 110, a transformer unit (not shown), a compensation unit 120, and a charging protocol unit 130, wherein:

[0042] The voltage conversion unit 110 is adapted to convert the type and amplitude of the power supply voltage and generate a converted voltage to the transformer unit and the compensation unit 120.

[0043] In some embodiments, the power supply voltage can be 220V AC, which can be converted to 310V DC by the voltage conversion unit 110.

[0044] The transformer unit includes a transformer, which includes a primary winding Wp, a secondary winding Ws, and an auxiliary winding Wa. The first end 2 of the primary winding Wp is coupled to the voltage conversion unit 110, and the second end 3 of the primary winding Wp is coupled to the compensation unit 120. The first end 4 of the auxiliary winding Wa serves as a feedback node VR. The output node A of the secondary winding Ws is coupled to the charging protocol unit 130, and outputs a transformer voltage to the charging protocol unit 130.

[0045] In some embodiments, the primary winding Wp and the auxiliary winding Wa are located on the same side.

[0046] In some embodiments, the second end 3 of the primary winding Wp is the same end as the first end 5 of the secondary winding Ws; the second end 6 of the secondary winding Ws is the same end as the first end 4 of the auxiliary winding Wa.

[0047] In some embodiments, the number of turns in the primary winding Wp is greater than the number of turns in the secondary winding Ws.

[0048] The compensation unit 120 is adapted to be in a selected state in response to the conversion voltage, and to change the feedback amplitude of the feedback terminal according to the voltage change of the feedback node, thereby generating a corresponding compensation voltage to the second terminal of the primary winding Wp to change the transformer voltage; wherein, the voltage change of the feedback node VR is determined according to the output current of the charging protocol unit 130.

[0049] Combination Figure 1 Briefly explain the working principle of the charger circuit in this solution:

[0050] Initially, after the voltage conversion unit 110 performs the voltage conversion process, in response to the converted voltage, the compensation unit 120 operates and provides a compensation voltage with a first amplitude to the second end of the primary winding Wp.

[0051] In this way, based on the transformer's transformation principle, the voltage of the primary winding Wp can be converted into a transformed voltage on the secondary winding Ws according to the transformation ratio, and then output to the charging protocol unit 130 through the output node A. The charging protocol unit 130 is connected to the electronic device, and therefore can charge the electronic device.

[0052] When the electronic device changes, the current on the charging protocol unit 130 changes. The charging protocol unit 130 is connected to the output node A, which is the first terminal 5 of the secondary winding Ws. Therefore, based on the transformation ratio, the voltage on the feedback node VR increases.

[0053] At this point, the compensation unit 120 changes the feedback amplitude at the feedback terminal, giving the compensation voltage a second amplitude, which causes a change in the voltage drop across the primary winding Wp. Furthermore, based on the transformation ratio, it changes the transformer voltage, making it follow the load changes of the electronic equipment, thereby achieving consistency in the terminal voltage of the electronic equipment under light and heavy loads.

[0054] In this embodiment, combined with Figure 1 and Figure 2 See Figure 3 The schematic diagram shown below illustrates the specific structure of a compensation unit in one embodiment of this utility model. Figure 1 and Figure 3 As shown, the compensation unit 120 may include: a control chip U1, a first feedback branch U2, and a second feedback branch U3, wherein:

[0055] The enable terminal VDD of the control chip U1 is adapted to input the conversion voltage, and the output terminal Drain is coupled to the second end of the primary winding Wp.

[0056] The first feedback branch U2 is connected to the first end of the auxiliary winding Wa and the second feedback branch U3, respectively.

[0057] The second feedback branch U3 is coupled to the first end of the auxiliary winding Wa and is adapted to be in a selected or disconnected state in response to the voltage change of the feedback node VR.

[0058] In this embodiment, when the second feedback branch U3 is in the selected state, the feedback terminal FB of the control chip U1 is the first feedback amplitude, so that the transformer voltage remains unchanged; when the second feedback branch U3 is in the disconnected state, the feedback terminal FB of the control chip U1 is the second feedback amplitude, and the transformer voltage increases.

[0059] In some embodiments, the first feedback amplitude and the second feedback amplitude are different. In other words, by changing the amplitude of the feedback terminal FB of the control chip U1, the change in compensation voltage is achieved, thereby enabling the transformer voltage to follow the change in output current.

[0060] More specifically, when the enable terminal VDD of control chip U1 receives the conversion voltage VCC, control chip U1 can operate. At this time, the first terminal 2 and the second terminal 3 of the primary winding Wp form a voltage with the upper positive and the lower negative. The second feedback branch U3 is then selected. Therefore, the second feedback branch U3 is connected to the feedback terminal FB of control chip U1. Control chip U1 will automatically adjust the output compensation voltage according to the power level, achieving a constant voltage function.

[0061] At this point, the transformer voltage remains unchanged, and thus the voltage before and after the transformer transformation remains unchanged.

[0062] When the output current of the charging protocol unit 130 changes, for example, if the output current increases, this will cause the voltage at output node A to increase. This, in turn, through the transformer, causes the voltage at the feedback node to increase, thereby disconnecting the path from the second feedback branch U3 to the feedback terminal FB of the control chip U1. At this time, the feedback at the feedback terminal FB of the control chip U1 is provided by the first feedback branch.

[0063] The change in feedback amplitude causes a change in the compensation voltage, which in turn enables adaptive adjustment of the transformer voltage.

[0064] In this embodiment, see Figure 3 The second feedback branch U2 may include: a selection transistor Q5, a selection resistor R60, a first diode D5, and a parallel voltage regulator (not shown in the figure), wherein:

[0065] The control terminal of the selection transistor Q5 is coupled to the first terminal of the first diode D5 and the parallel voltage regulator, respectively. The first terminal of the selection transistor Q5 is coupled to the feedback node VR. The second terminal of the selection transistor Q5 is coupled to the feedback terminal FB of the control chip U1 through the selection resistor R60.

[0066] The second terminal of the first diode D5 is coupled to the parallel voltage regulator.

[0067] The parallel voltage regulator includes: a first voltage-regulating resistor R66, a second voltage-regulating resistor R62, a first voltage-dividing resistor R63 and a second voltage-dividing resistor R65, and a Zener transistor U8. The first terminal of the first voltage-regulating resistor R66 is coupled to the first terminal of the first diode D5 and the control terminal of the selector transistor Q5. The second terminal of the first voltage-regulating resistor R66 is coupled to the first terminal of the second voltage-regulating resistor R62 and the first terminal of the first voltage-dividing resistor R63, and receives a feedback voltage. The second terminal of the second voltage-regulating resistor R62 is coupled to the second terminal of the Zener transistor U8 and the second terminal of the first diode D5. The second terminal of the first voltage-dividing resistor R63 is coupled to the first terminal of the second voltage-dividing resistor R65 and the control terminal of the Zener transistor U3. The first terminal of the Zener transistor U8 is coupled to the second terminal of the second voltage-dividing resistor R62 and connected in parallel to a first ground G1.

[0068] Specifically, in the initial stage, the feedback voltage VDD1 is relatively small (changing with the voltage at the feedback node VR). At this time, the voltage divided by the first voltage divider resistor R63 and the second voltage divider resistor R65 is low, and the Zener transistor U8 is in the off state. Therefore, based on VDD1, the selection transistor Q5 is turned on. At this time, the first voltage regulator resistor R66, the second voltage regulator resistor R62, the first voltage divider resistor R63, and the second voltage divider resistor R65 are connected to the feedback terminal FB of the control chip U1.

[0069] When the output current of the charging protocol unit 130 increases, the voltage on the feedback node VR increases, which in turn increases VDD1. Consequently, the voltage division on the first voltage divider resistor R63 and the second voltage divider resistor R65 increases, thus turning on the Zener transistor U8 and turning off the selection transistor Q5. As a result, the feedback on the feedback terminal FB of the control chip U1 becomes the feedback on the first feedback branch U1.

[0070] Furthermore, when the selection transistor Q5 is turned on, the first diode D5 can play a freewheeling role.

[0071] In this embodiment, the first feedback branch U1 includes: a first feedback resistor R11, a second feedback resistor R12, a third feedback resistor R13, and a feedback capacitor C7, wherein: the first end of the first feedback resistor R11 is coupled to the feedback node VR, and the second end of the first feedback resistor R11 is coupled to the second feedback resistor R12, the third feedback resistor R13, the feedback capacitor C7, and the feedback terminal FB, respectively; the second ends of the second feedback resistor R12, the third feedback resistor R13, and the feedback capacitor C7 are all connected to the first ground G1.

[0072] Specifically, the first feedback resistor R11, the second feedback resistor R12, and the third feedback resistor R13 can divide the voltage on the feedback node VR, so that the voltage drop across the second feedback resistor R12 and the third feedback resistor R13 can be used as a feedback signal output to the feedback terminal FB of the control chip U1.

[0073] Because the feedback values ​​corresponding to the first feedback branch U2 and the second feedback branch U2 are different, the transformer voltage changes after adjustment.

[0074] In this embodiment, see next. Figure 3 The control chip U1 also has a ground terminal GND, and the ground terminal GND is coupled to the enable terminal VDD through the grounding capacitor C8, and connected to the first ground G1.

[0075] And the detection terminal CS, and the detection terminal CS is coupled to the first ground G1 through the first detection resistor R10 and the second detection resistor R14.

[0076] In this embodiment, see Figure 3 The voltage conversion unit 110 may include: a first filter module, a rectifier module BD1, and a second filter module.

[0077] Wherein: the first filter module is coupled to the rectifier module BD1 and is suitable for inputting the power supply voltage; the rectifier module BD1 is coupled to the second filter module and is suitable for converting the type of power supply voltage; the second filter module is coupled to the first end 2 of the primary winding Wp.

[0078] More specifically, the first filtering module may include: a common-mode inductor L1, wherein the first terminal 1 and the second terminal 2 of the common-mode inductor are adapted to receive the supply voltage (e.g., Figure 3 (Illustrated L and N), the third terminal 3 and the fourth terminal 4 of the common mode inductor L1 are coupled to the rectifier module BD1.

[0079] By setting up the first filtering module, the power supply voltage can be filtered, thereby improving the quality of the power supply voltage.

[0080] The rectifier module BD1 includes a full-bridge rectifier circuit composed of diodes. For the specific construction of the full-bridge rectifier circuit, please refer to existing examples.

[0081] The second filtering module may include: a first filtering capacitor C1, a second filtering capacitor C2, a third filtering capacitor C12, and a filtering inductor L2, wherein the first terminal of the first filtering capacitor C1 is connected to the first terminal of the filtering inductor L2, the second terminals of the first filtering capacitor C1, the second filtering capacitor C2, and the third filtering capacitor C12 are coupled together and connected to a first ground G1; the second terminal of the filtering inductor L2 is coupled to the first terminals of the second filtering capacitor C2 and the third filtering capacitor C12, respectively.

[0082] In other words, the second filtering module is an LC filter circuit.

[0083] In this embodiment, the charging protocol unit 130 may include multiple charging protocol modules, each of which includes a matching charging protocol IC and a USB port, wherein the charging protocol IC is coupled to the output node and the corresponding USB port respectively.

[0084] For example, see Figure 2 The diagram shows two charging protocol modules, U4 and U5, which have the same structure. Charging protocol module U4 is connected to USB1, and charging protocol module U5 is connected to USB2.

[0085] More specifically, the charging protocol modules U4 and U5 both include: two input terminals VIN, a power supply terminal VDD, two ground terminals GND, two output terminals OUT, a negative signal terminal DM, a positive signal terminal DP, and a connectionless terminal NC.

[0086] More specifically, in the charging protocol module U4, both input terminals VIN are connected to the output node A, and are connected to the supply terminal VDD through the first supply resistor R40; and are connected to the second ground G2 through the first supply capacitor C40, while the supply terminal VDD is connected to the second ground G2 through the second supply capacitor C41.

[0087] After the two output terminals OUT are connected, they are connected to USB1, and both the negative signal terminal DM and the positive signal terminal DP are connected to USB1. Thus, electronic device 1 is adapted through USB1, and the first voltage VOUT1 is output.

[0088] In addition, the two output terminals OUT are also connected to the second ground through the first output capacitor C42.

[0089] Correspondingly, in the charging protocol module U5, both input terminals VIN are connected to the output node A, and are connected to the supply terminal VDD through the second supply resistor R50; and are connected to the second ground G2 through the third supply capacitor C50, while the supply terminal VDD is connected to the second ground G2 through the fourth supply capacitor C51.

[0090] After the two output terminals OUT are connected, they are connected to USB2. The negative signal terminal DM and the positive signal terminal DP are both connected to USB2, thereby adapting electronic device 2 through USB2 and outputting the second voltage VOUT2.

[0091] In addition, the two output terminals OUT are also connected to the second ground through the second output capacitor C52.

[0092] In one specific embodiment, the charging protocol modules U4 and U5 can be model CW3047.

[0093] Furthermore, by setting up multiple charging protocol modules, it can power multiple electronic devices.

[0094] It should be noted that, in this embodiment, a mica capacitor is provided between the first ground G1 and the second ground G2.

[0095] In practical applications, as mentioned earlier, the DC voltage generated after conversion by the voltage conversion unit is 310V. However, the operating voltage of the compensation unit is generally lower.

[0096] Based on this, see next. Figure 1The charger circuit may further include: a voltage divider unit 140, coupled to the enable terminal of the voltage conversion unit 110 and the compensation unit 120, adapted to divide the converted voltage output by the voltage conversion unit to obtain a divided voltage.

[0097] In some embodiments, see Figure 3 The voltage divider unit 140 may include a third voltage divider resistor R1 and a fourth voltage divider resistor R2, wherein the first end of the third voltage divider resistor R1 is coupled to the voltage conversion unit 110 and the first end 2 of the primary winding Wp, respectively, and the second end of the third voltage divider resistor R1 is coupled to the fourth voltage divider resistor R2; the second end of the fourth voltage divider resistor R2 is coupled to the enable terminal of the compensation unit 120 (e.g., control signal U1).

[0098] By setting the third voltage divider resistor R1 and the fourth voltage divider resistor R2, a suitable power supply voltage can be provided to the compensation unit 120, thus ensuring the safe and stable operation of the compensation unit 120.

[0099] As can be seen from the foregoing, this scheme achieves the change of feedback signal by selecting the on / off state of transistor Q5.

[0100] In practical work, the inventors discovered that at the moment when the turn-on transistor Q5 is turned off, Q5 acts as a capacitor, causing the output terminal Drain of the control chip U1 to discharge. The released peak voltage will damage the circuit and reduce the performance of the charger circuit.

[0101] Based on this, see next. Figure 1 The charger circuit may further include: an absorption unit 150, coupled to the output terminal Drain of the compensation unit 120, adapted to absorb the peak voltage of the output terminal Drain of the compensation unit 120 when the second feedback branch U3 is in the off state.

[0102] In one embodiment, see Figure 3 The absorption unit 150 may include: a first absorption resistor R5, a second absorption resistor R3, a third absorption resistor R4, a second diode D1, and an absorption capacitor C3. The first end of the first absorption resistor R5 is coupled to the output terminal Drain of the compensation unit 120, and the second end of the first absorption resistor R5 is coupled to the first end of the second diode D1. The second end of the second diode D1 is coupled to the second ends of the second absorption resistor R3, the third absorption resistor R4, and the absorption capacitor C3, respectively. The first ends of the second absorption resistor R3, the third absorption resistor R4, and the absorption capacitor C3 are also coupled.

[0103] In other words, the absorption unit 150 is an RCD absorption circuit. Furthermore, by employing a second diode D1, the flow direction of the peak voltage is ensured to be solely from the first absorption resistor R5 to the second absorption resistor R4, which significantly improves the operational stability of the charger circuit.

[0104] Furthermore, at the instant the turn-off transistor Q5 is turned off, the junction capacitance of the turn-off transistor Q5 will also discharge, thus requiring a corresponding discharge circuit.

[0105] Based on this, see next. Figure 1 The charger circuit may further include a discharge circuit unit 160, which is coupled to the first feedback branch U2 and the feedback node VR respectively, and is adapted to cooperate with the first feedback branch U2 to provide a discharge circuit for the junction capacitance voltage on the second feedback branch U3 when the second feedback branch U3 is in the off state.

[0106] In some embodiments, the discharge circuit unit includes: a first circuit resistor R7, a third diode D2, a second circuit resistor R8, a fourth diode D4, a first circuit capacitor C6, a second circuit capacitor C4, and an energy storage capacitor C5. The first terminal of the first circuit resistor R7 is coupled to the feedback node VR. The second terminal of the first circuit resistor R7 is coupled to the first terminal of the third diode D2 and the first terminal of the first circuit capacitor C6. The second terminal of the third diode D2 is coupled to the second terminal of the second circuit resistor R8, the first terminal of the energy storage capacitor C5, and the first terminal of the fourth diode D4, and is connected to VDD1. The second terminal of the first circuit capacitor C6 is coupled to the first terminal of the second circuit resistor R8. The second terminals of the energy storage capacitor C6 and the second terminals of the second circuit capacitor C4 are both connected to a first ground G1. The first terminal of the second circuit capacitor C4 is coupled to the second terminal of the fourth diode D4 and is connected to the voltage divider voltage VCC.

[0107] Furthermore, by forming a loop along the third diode D2 to the fourth diode D4, the voltage drop across the first terminal 4 and the second terminal 1 of the auxiliary winding is positive at the bottom and negative at the top. This makes the corresponding terminal of the secondary winding Ws opposite to the corresponding terminal of the primary winding Wp, thus providing a stable constant current DC power to the subsequent circuit (i.e., the charging protocol unit 130).

[0108] In some embodiments, to improve the voltage quality at output node A, see then... Figure 1 and Figure 3 The charger circuit further includes: an output module disposed between the output node A and the charging protocol unit 130, wherein the output module includes:

[0109] The circuit comprises a rectifier-filter branch 172 consisting of a first electrolytic capacitor C9 and a second electrolytic capacitor C10, and a relay branch 174 consisting of a relay resistor R15, a relay capacitor C11, and a relay KA. The first terminals of both the first electrolytic capacitor C9 and the second electrolytic capacitor C10 are coupled to the first terminal 5 of the secondary winding Ws. The second terminals of both the first electrolytic capacitor C9 and the second electrolytic capacitor C10, serving as the output node A, are connected to the second ground G2 and coupled to the second terminals of the relay KA and the relay capacitor C11. The first terminals of the relay resistor R15 and the relay KA are coupled to the second terminal 6 of the secondary winding Ws, and the second terminal of the relay resistor R15 is coupled to the first terminal of the relay capacitor C11.

[0110] Specifically, the first electrolytic capacitor C9 and the second electrolytic capacitor C10, which are connected to the secondary winding Ws, can rectify and filter the transformer voltage, thereby improving the quality of the transformer voltage.

[0111] It is understood that the above description provides multiple embodiment solutions, and the optional methods described in each embodiment solution can be combined with each other and cross-referenced without conflict, thereby extending to a variety of possible embodiment solutions, all of which can be considered as the embodiment solutions disclosed in this disclosure.

[0112] While the embodiments disclosed herein are as described above, this utility model is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of this utility model; therefore, the scope of protection of this utility model should be determined by the scope defined in the claims.

Claims

1. A charger circuit, characterized by, include: The system comprises a voltage conversion unit, a transformer unit, a compensation unit, and a charging protocol unit, wherein: The voltage conversion unit is adapted to convert the type and amplitude of the power supply voltage and generate a converted voltage to the transformer unit and the compensation unit; The transformer unit includes a transformer, which includes a primary winding, a secondary winding, and an auxiliary winding. The first end of the primary winding is coupled to the voltage conversion unit, and the second end of the primary winding is coupled to the compensation unit. The first end of the auxiliary winding serves as a feedback node. The output node of the secondary winding is coupled to the charging protocol unit, and outputs a transformer voltage to the charging protocol unit. The compensation unit is adapted to be in a selected state in response to the conversion voltage, and to change the feedback amplitude of the feedback terminal according to the voltage change of the feedback node, thereby generating a corresponding compensation voltage to the second terminal of the primary winding to change the transformer voltage; wherein the voltage change of the feedback node is determined according to the output current of the charging protocol unit.

2. The charger circuit of claim 1, wherein, The compensation unit includes: a control chip, a first feedback branch, and a second feedback branch, wherein: The enable terminal of the control chip is adapted to receive the conversion voltage, and the output terminal is coupled to the second end of the primary winding. The first feedback branch is connected to the first end of the auxiliary winding and the second feedback branch, respectively. The second feedback branch is coupled to the first end of the auxiliary winding and is adapted to be in a selected or disconnected state in response to the voltage change of the feedback node. Specifically, when the second feedback branch is in the selected state, the feedback terminal of the control chip is the first feedback amplitude, so that the transformer voltage remains unchanged; when the second feedback branch is in the open state, the feedback terminal of the control chip is the second feedback amplitude, the transformer voltage increases, and the first feedback amplitude and the second feedback amplitude are different.

3. The charger circuit of claim 2, wherein, The second feedback branch includes: a selection transistor, a selection resistor and a first diode, and a parallel voltage regulator, wherein: The control terminal of the selection transistor is coupled to the first terminal of the first diode and the parallel voltage regulator, respectively. The first terminal of the selection transistor is coupled to the feedback node. The second terminal of the selection transistor is coupled to the feedback terminal of the control chip through the selection resistor. The second terminal of the first diode is coupled to the parallel voltage regulator; The parallel voltage regulator includes: a first voltage-regulating resistor, a second voltage-regulating resistor, a first voltage-dividing resistor, a second voltage-dividing resistor, and a Zener transistor. The first terminal of the first voltage-regulating resistor is coupled to the first terminal of the first diode and the control terminal of the selector transistor. The second terminal of the first voltage-regulating resistor is coupled to the first terminal of the second voltage-regulating resistor and the first terminal of the first voltage-dividing resistor, and receives a feedback voltage. The second terminal of the second voltage-regulating resistor is coupled to the second terminal of the Zener transistor and the second terminal of the first diode. The second terminal of the first voltage-dividing resistor is coupled to the first terminal of the second voltage-dividing resistor and the control terminal of the Zener transistor. The first terminal of the Zener transistor is coupled to the second terminal of the second voltage-dividing resistor and connected in parallel to a first ground.

4. The charger circuit according to claim 2, characterized in that, The first feedback branch includes: a first feedback resistor, a second feedback resistor, a third feedback resistor, and a feedback capacitor, wherein: the first end of the first feedback resistor is coupled to the feedback node, and the second end of the first feedback resistor is coupled to the second feedback resistor, the third feedback resistor, the feedback capacitor, and the feedback terminal respectively; the second ends of the second feedback resistor, the third feedback resistor, and the feedback capacitor are all connected to a first ground.

5. The charger circuit according to claim 2, characterized in that, The charger circuit also includes at least one or more of the following: The voltage divider unit is coupled to the enable terminal of the voltage conversion unit and the compensation unit, and is adapted to divide the converted voltage output by the voltage conversion unit to obtain the divided voltage. An absorption unit, coupled to the output terminal of the compensation unit, is adapted to absorb the spike voltage at the output terminal of the compensation unit when the second feedback branch is in an open state.

6. The charger circuit according to claim 5, characterized in that, The voltage divider unit includes a third voltage divider resistor and a fourth voltage divider resistor, wherein the first end of the third voltage divider resistor is coupled to the voltage conversion unit and the first end of the primary winding, respectively, and the second end of the third voltage divider resistor is coupled to the fourth voltage divider resistor; the second end of the fourth voltage divider resistor is coupled to the enable terminal of the compensation unit. The absorption unit includes: a first absorption resistor, a second absorption resistor, a third absorption resistor, a second diode, and an absorption capacitor. The first end of the first absorption resistor is coupled to the output end of the compensation unit, and the second end of the first absorption resistor is coupled to the first end of the second diode. The second end of the second diode is coupled to the second ends of the second absorption resistor, the third absorption resistor, and the absorption capacitor, respectively. The first ends of the second absorption resistor, the third absorption resistor, and the absorption capacitor are coupled to each other.

7. The charger circuit according to claim 1, characterized in that, The voltage conversion unit includes: a first filter module, a rectifier module, and a second filter module, wherein: the first filter module is coupled to the rectifier module and is adapted to input the power supply voltage; the rectifier module is coupled to the second filter module and is adapted to convert the type of power supply voltage; the second filter module is coupled to the first end of the primary winding.

8. The charger circuit according to claim 7, characterized in that, The voltage conversion unit satisfies at least one or more of the following: The first filtering module includes a common-mode inductor, wherein the first and second ends of the common-mode inductor are adapted to receive the supply voltage, and the third and fourth ends of the common-mode inductor are coupled to the rectifier module. The rectifier module includes: a full-bridge rectifier circuit composed of diodes; The second filtering module includes: a first filtering capacitor, a second filtering capacitor, a third filtering capacitor, and a filtering inductor, wherein the first terminal of the first filtering capacitor is connected to the first terminal of the filtering inductor, and the second terminals of the first filtering capacitor, the second filtering capacitor, and the third filtering capacitor are coupled together and connected to a first ground; the second terminal of the filtering inductor is coupled to the first terminals of the second filtering capacitor and the third filtering capacitor, respectively.

9. The charger circuit according to claim 1, characterized in that, The charging protocol unit includes multiple charging protocol modules, each of which includes a matching charging protocol IC and a USB port. The charging protocol IC is coupled to the output node and the corresponding USB port, respectively.

10. The charger circuit according to claim 1, characterized in that, Also includes: An output module is disposed between the output node and the charging protocol unit, wherein the output module includes: The circuit includes a rectifier and filter branch consisting of a first electrolytic capacitor and a second electrolytic capacitor, and a relay branch consisting of a relay resistor, a relay capacitor, and a relay. The first terminals of both the first and second electrolytic capacitors are coupled to the first terminal of the secondary winding and serve as the output node. The second terminals of both the first and second electrolytic capacitors are connected to a second ground and are coupled to the second terminals of the relay and the relay capacitor. The first terminals of the relay resistor and the relay are coupled to the second terminal of the secondary winding, and the second terminal of the relay resistor is coupled to the first terminal of the relay capacitor.

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