A constant voltage and constant current control circuit, circuit system and electronic equipment

Abstract

This invention provides a constant voltage and constant current control circuit, circuit system, and electronic device, including a current acquisition and amplification module, a first filtering module, a second filtering module, a voltage closed-loop control module, a current closed-loop control module, and a constant current and constant voltage regulation module. The voltage closed-loop control module outputs a constant voltage control signal based on the acquired voltage and reference voltage of the transformer output voltage, and filters the voltage pulse width modulation signal using the first filtering module to obtain a voltage regulation signal that adjusts the magnitude of the constant voltage control signal. The current closed-loop control module outputs a constant current control signal based on the acquired and amplified current of the transformer output current and a reference current, and filters the current pulse width modulation signal using the second filtering module to obtain a current regulation signal that adjusts the magnitude of the constant current control signal. The constant current and constant voltage regulation module regulates the constant voltage value of the output voltage and the constant current value of the output current based on the constant voltage control signal.

Description

Technical Field

[0001] This utility model relates to the field of battery charger control technology, and in particular to a constant voltage and constant current regulating circuit, circuit system and electronic equipment. Background Technology

[0002] With the popularization of new energy technology products, batteries are being used in a wider range of products and scenarios, which puts higher demands on chargers. In addition to keeping the output voltage and output current of the charger constant, it is also necessary to regulate the constant values ​​of the output voltage and output current.

[0003] However, existing chargers typically cannot regulate the constant values ​​of both output voltage and output current. Utility Model Content

[0004] This invention provides a constant voltage and constant current control circuit, circuit system and electronic equipment, which can flexibly adjust the constant values ​​of the output voltage and output current while maintaining the constant output voltage and output current of the transformer.

[0005] To solve the above-mentioned technical problems, a first aspect of the present invention provides a constant voltage and constant current control circuit, the constant voltage and constant current control circuit comprising: A current acquisition and amplification module is provided, wherein the input terminal of the current acquisition and amplification module is connected to the current output terminal of the transformer, and the output terminal of the current acquisition and amplification module outputs an acquisition and amplification current, which is formed by acquiring and amplifying the output current of the current output terminal of the transformer. The first filtering module has an input terminal connected to an externally input voltage pulse width modulation signal and an output terminal outputting a voltage adjustment signal, which is formed based on the filtered voltage pulse width modulation signal. The second filtering module has an input terminal connected to an externally input current pulse width modulation signal and an output terminal outputting a current adjustment signal, which is formed based on the filtered current pulse width modulation signal. A voltage closed-loop control module, wherein the first input terminal of the voltage closed-loop control module is connected to the voltage output terminal of the transformer, the second input terminal of the voltage closed-loop control module is connected to the reference voltage, the third input terminal of the voltage closed-loop control module is connected to the output terminal of the first filter module, and the voltage closed-loop control module outputs a constant voltage regulation signal. A current closed-loop control module, wherein the first input terminal of the current closed-loop control module is connected to the output terminal of the current acquisition and amplification module, the second input terminal of the current closed-loop control module is connected to the reference current, the third input terminal of the current closed-loop control module is connected to the output terminal of the second filter module, and the current closed-loop control module outputs a constant current regulation signal. A constant current and constant voltage regulation module is provided. The first input terminal of the constant current and constant voltage regulation module is connected to the voltage closed-loop control module, the second input terminal of the constant current and constant voltage regulation module is connected to the current closed-loop control module, and the output terminal of the constant current and constant voltage regulation module is connected to the primary winding of the transformer. The constant voltage regulation module regulates the constant voltage value of the output voltage according to the constant voltage regulation signal, and regulates the constant current value of the output current according to the constant current regulation signal.

[0006] Optionally, the first filtering module includes: a first filtering resistor and a first filtering capacitor; the first end of the first filtering resistor is connected to the voltage pulse width modulation signal, the second end of the first filtering resistor is connected to the first end of the first filtering capacitor and outputs the voltage adjustment signal, and the second end of the first filtering capacitor is connected to ground.

[0007] Optionally, the first filtering module further includes: a second filtering resistor and a second filtering capacitor; the first end of the second filtering resistor is connected to the second end of the first filtering resistor, the second end of the second filtering resistor is connected to the first end of the second filtering capacitor and outputs the voltage regulation signal, and the second end of the second filtering capacitor is also connected to ground.

[0008] Optionally, the second filtering module includes: a third filtering resistor and a third filtering capacitor; the first end of the third filtering resistor is connected to the current pulse width modulation signal, the second end of the third filtering resistor is connected to the first end of the third filtering capacitor and outputs the current adjustment signal, and the second end of the third filtering capacitor is connected to ground.

[0009] Optionally, the second filtering module further includes: a fourth filtering resistor and a fourth filtering capacitor; the first end of the fourth filtering resistor is connected to the second end of the third filtering resistor, the second end of the fourth filtering resistor is connected to the first end of the fourth filtering capacitor and outputs the current adjustment signal, and the second end of the fourth filtering capacitor is connected to ground.

[0010] Optionally, the current acquisition and amplification module includes: an acquisition circuit and a first operational amplifier circuit; The first input terminal of the acquisition circuit is connected to the first port of the current output terminal of the transformer, the second input terminal of the acquisition circuit is connected to the second port of the current output terminal of the transformer, the first output terminal of the acquisition circuit outputs the first differential signal of the acquisition current, and the second output terminal of the acquisition circuit outputs the second differential signal of the acquisition current. The first input terminal of the first operational amplifier circuit is connected to the first output terminal of the acquisition circuit, the second input terminal of the first operational amplifier circuit is connected to the second output terminal of the acquisition circuit, and the output terminal of the first operational amplifier circuit outputs the acquisition amplification current.

[0011] Optionally, the current acquisition and amplification module further includes a first current compensation circuit, wherein a first terminal of the first current compensation circuit is connected to the reference voltage, a second terminal of the first current compensation circuit is connected to ground, a third terminal of the first current compensation circuit is connected to the first input terminal of the first operational amplifier circuit, and a fourth terminal of the first current compensation circuit is connected to the second input terminal of the first operational amplifier circuit.

[0012] Optionally, the voltage closed-loop control module includes a voltage divider circuit and a second operational amplifier circuit; The input terminal of the voltage divider circuit is connected to the output voltage of the transformer as the first input terminal of the voltage closed-loop control module, and the output terminal of the voltage divider circuit outputs the divided voltage. The first input terminal of the second operational amplifier circuit serves as the second input terminal of the voltage closed-loop control module, and also serves as the third input terminal of the voltage closed-loop control module. The second input terminal of the second operational amplifier circuit is connected to the output terminal of the voltage divider circuit, and the output terminal of the second operational amplifier circuit outputs the constant voltage regulation signal.

[0013] Optionally, the voltage closed-loop control module further includes a first overcharge protection resistor, a first overcharge protection capacitor, and a second overcharge protection capacitor; the first end of the first overcharge protection resistor is connected to the first end of the first voltage acquisition resistor, the second end of the first overcharge protection resistor is connected to the first end of the first overcharge protection capacitor, the second end of the first overcharge protection capacitor is connected to the first end of the second overcharge protection capacitor, and the second end of the second overcharge protection capacitor is connected to the second end of the second voltage acquisition resistor.

[0014] Optionally, the current closed-loop control module includes a third operational amplifier circuit, a current filter circuit, and a second current compensation circuit. The input terminal of the current filtering circuit serves as the third input terminal of the voltage closed-loop control module, and the output terminal of the current filtering circuit outputs a current adjustment and filtering signal. The first input terminal of the third operational amplifier circuit serves as the first input terminal of the current closed-loop control module, the second input terminal of the third operational amplifier serves as the second input terminal of the current closed-loop control module, and the second input terminal of the third operational amplifier circuit is also connected to the output terminal of the current filter circuit. The output terminal of the third operational amplifier circuit outputs the constant current control signal. The first terminal of the second current compensation circuit is connected to the first input terminal of the third operational amplifier circuit, and the second terminal of the second current compensation circuit is connected to the output terminal of the third operational amplifier circuit.

[0015] Optionally, the constant current and constant voltage regulation module includes a first isolation diode, a second isolation diode, a first regulating resistor, and an optocoupler regulator; the cathode of the first isolation diode is connected to the constant voltage regulation signal, and the anode of the first isolation diode is connected to the first terminal of the optocoupler regulator; the cathode of the second isolation diode is connected to the constant current regulation signal, and the anode of the second isolation diode is connected to the first terminal of the optocoupler regulator; the first terminal of the first regulating resistor is connected to the power supply voltage, and the second terminal of the first regulating resistor is connected to the second terminal of the optocoupler regulator; the optocoupler regulator controls the input voltage of the primary winding of the transformer according to the constant voltage regulation signal to regulate the constant voltage value of the output voltage of the secondary winding of the transformer; the optocoupler regulator also controls the input voltage of the primary winding of the transformer according to the constant current regulation signal to regulate the constant current value of the output current of the secondary winding of the transformer.

[0016] A second aspect of the present invention provides a circuit system including the constant voltage and constant current control circuit provided in the first aspect of the present invention.

[0017] A third aspect of the present invention provides an electronic device including the circuit system provided in the second aspect of the present invention.

[0018] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: In the constant voltage and constant current control circuit provided by this invention, the voltage closed-loop control module outputs a constant voltage control signal based on the acquired voltage and reference voltage of the transformer output voltage, and adjusts the magnitude of the constant voltage control signal by filtering the externally input voltage pulse width modulation signal using a first filtering module to obtain a voltage adjustment signal. The current closed-loop control module outputs a constant current control signal based on the acquired and amplified current obtained by the current acquisition and amplification module from the transformer output current and the reference current, and adjusts the magnitude of the constant current control signal by filtering the externally input current pulse width modulation signal using a second filtering module to obtain a current adjustment signal. The constant current and constant voltage control module adjusts the constant voltage value of the output voltage and the constant current value of the output current according to the constant voltage control signal.

[0019] Furthermore, the first compensation resistor, the second compensation resistor, the third compensation resistor, the fourth compensation resistor, and the fifth compensation resistor constitute the compensation circuit of the first operational amplifier to correct the bias voltage of the first operational amplifier, thereby improving the accuracy of the acquired amplified current. The fifth filter capacitor, the sixth filter capacitor, the seventh filter capacitor, and the eighth filter capacitor constitute the noise filtering network of the first operational amplifier to filter the first differential signal and the second differential signal of the output current, as well as the ground terminal of the first operational amplifier.

[0020] Furthermore, the first overcharge protection resistor, the first overcharge protection capacitor, and the second overcharge protection capacitor work together to prevent the output voltage from overcharging when the charger is turned on.

[0021] Furthermore, the first compensation capacitor, the second compensation capacitor, the third compensation capacitor, and the seventh compensation resistor are used to provide feedback compensation for the third operational amplifier, and the sixth compensation resistor is used to compensate the input signal of the third operational amplifier. The ninth filter capacitor and the sixth filter resistor are used to filter the current adjustment signal, and the tenth filter capacitor is used to filter the noise between the inverting input terminal and the non-inverting input terminal of the third operational amplifier. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the circuit structure of the constant voltage and constant current control circuit provided in the embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the circuit structure of the constant voltage and constant current control circuit provided in the embodiment of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the circuit structure of a constant voltage and constant current control circuit provided in another embodiment of the present invention. Figure 1 ; Figure 4 This is a schematic diagram of the circuit structure of a reference voltage generation circuit provided in another embodiment of the present invention. Detailed Implementation

[0023] As described in the background section, existing chargers typically cannot regulate the constant values ​​of both the output voltage and the output current.

[0024] In view of this, the technical solution of the present invention provides a constant voltage and constant current regulation circuit, including a current acquisition and amplification module, a first filtering module, a second filtering module, a voltage closed-loop control module, a current closed-loop control module, and a constant current and constant voltage regulation module. The voltage closed-loop control module outputs a constant voltage regulation signal based on the acquired voltage and reference voltage of the transformer output voltage, and adjusts the magnitude of the constant voltage regulation signal by filtering an externally input voltage pulse width modulation signal using the first filtering module. The current closed-loop control module outputs a constant current regulation signal based on the acquired and amplified current obtained by the current acquisition and amplification module of the transformer output current and the reference current, and adjusts the magnitude of the constant current regulation signal by filtering an externally input current pulse width modulation signal using the second filtering module. The constant current and constant voltage regulation module regulates the constant voltage value of the output voltage and the constant current value of the output current according to the constant voltage regulation signal.

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0028] Figure 1 This is a schematic diagram of the circuit structure of the constant voltage and constant current control circuit provided in an embodiment of the present invention.

[0029] Please refer to Figure 1The constant voltage and constant current control circuit provided in this embodiment is used to adjust the constant voltage value of the transformer's output voltage Vout1 and the constant current value of the transformer's output current Iout1.

[0030] Specifically, the transformer's output voltage Vout1 is used to characterize the output voltage Vout1 of the transformer's secondary winding. The transformer's output current Iout1 is used to characterize the output current Iout1 of the transformer's secondary winding. The output current Iout1 is acquired through a current acquisition resistor located on the transformer's secondary winding to output a first differential signal Iout1+ and a second differential signal Iout1- of the output current.

[0031] The constant voltage and constant current control circuit includes a current acquisition and amplification module 10, a first filter module 20, a second filter module 30, a voltage closed-loop control module 40, a current closed-loop control module 50, and a constant current and constant voltage adjustment module 60.

[0032] In this embodiment, the input terminal of the current acquisition and amplification module 10 is connected to the current output terminal of the transformer, and the output terminal of the current acquisition and amplification module outputs an acquisition and amplification current, which is formed by acquiring and amplifying the output current of the current output terminal of the transformer.

[0033] Please refer to Figure 1 and Figure 2 In this embodiment, the current acquisition and amplification module 10 includes: an acquisition circuit 11 and a first operational amplifier circuit 12.

[0034] The first input terminal of the acquisition circuit 11 is connected to the first differential signal Iout1+ of the output current, the second input terminal of the acquisition circuit 11 is connected to the second differential signal Iout1- of the output current, the first output terminal of the acquisition circuit 11 outputs the first differential signal Iout1+ of the acquisition current, and the second output terminal of the acquisition circuit 11 outputs the second differential signal Iout1- of the acquisition current.

[0035] The first input terminal of the first operational amplifier circuit 12 is connected to the first output terminal of the acquisition circuit 11, the second input terminal of the first operational amplifier circuit 12 is connected to the second output terminal of the acquisition circuit 11, and the output terminal of the first operational amplifier circuit 12 outputs the acquisition amplification current.

[0036] Please continue to refer to this. Figure 1 and Figure 2 The acquisition circuit 11 specifically includes a first current acquisition resistor R12, a second current acquisition resistor R19, a third current acquisition resistor R9, and a fourth current acquisition resistor R23.

[0037] The first operational amplifier circuit 12 includes a first feedback resistor R22, a first output resistor R11, and a first operational amplifier amp1.

[0038] The first terminal of the first current acquisition resistor R12 is connected to the first differential signal Iout1+ of the output current; the first terminal of the second current acquisition resistor R19 is connected to the second differential signal Iout1- of the output current; the second terminal of the first current acquisition resistor R12 is connected to the first terminal of the third current acquisition resistor R9; the second terminal of the second current acquisition resistor R19 is connected to the first terminal of the fourth current acquisition resistor R23; the second terminal of the third current acquisition resistor R9 is connected to the non-inverting input terminal of the first operational amplifier amp1; the second terminal of the fourth current acquisition resistor R23 is connected to the inverting input terminal of the first operational amplifier amp1; the first terminal of the first feedback resistor R22 is connected to the second terminal of the fourth current acquisition resistor R23; the second terminal of the first feedback resistor R22 is connected to the output terminal of the first operational amplifier amp1; the first terminal of the first output resistor R11 is connected to the output terminal of the operational amplifier; and the second terminal of the first output resistor R11 outputs the acquired and amplified current Iout2.

[0039] In this embodiment, the input terminal of the first filtering module is connected to an externally input voltage pulse width modulation signal, and the output terminal of the first filtering module outputs a voltage adjustment signal, which is formed based on the filtered voltage pulse width modulation signal. Please continue to refer to this. Figure 1 and Figure 2 The first filtering module includes a first filtering resistor R29 and a first filtering capacitor C13. The first terminal of the first filtering resistor R29 is connected to the voltage pulse width modulation signal Vpwn, the second terminal of the first filtering resistor R29 is connected to the first terminal of the first filtering capacitor C13 and outputs the voltage adjustment signal Vset, and the second terminal of the first filtering capacitor C13 is connected to ground.

[0040] Please refer to Figure 3 In another embodiment, the first filtering module 20 includes a first filtering resistor R29, a second filtering resistor R28, a first filtering capacitor C13, and a second filtering capacitor C12.

[0041] The first terminal of the first filter resistor R29 is connected to the voltage pulse width modulation signal Vpwn. The second terminal of the first filter resistor R29 is connected to the first terminal of the first filter capacitor C13 and the first terminal of the second filter resistor R28. The second terminal of the second filter resistor R28 outputs the voltage adjustment signal Vset and is connected to the first terminal of the second filter capacitor C12. The second terminals of the first filter capacitor C13 and the second terminal of the second filter capacitor C12 are both grounded to SGND.

[0042] The filter circuit, consisting of the first filter resistor R29, the second filter resistor R28, the first filter capacitor C13, and the second filter capacitor C12, filters the externally input voltage pulse width modulation signal Vpwn to output a DC voltage regulation signal Vset. The constant voltage value of the transformer's output voltage Vout1 is then regulated through the voltage regulation signal Vset.

[0043] In this embodiment, the input terminal of the second filtering module is connected to an externally input current pulse width modulation signal, and the output terminal of the second filtering module outputs a current adjustment signal, which is formed based on the filtered current pulse width modulation signal.

[0044] Please continue to refer to this. Figure 1 and Figure 2 The second filtering module 30 includes a third filtering resistor R33 and a third filtering capacitor C19. The first terminal of the third filtering resistor R33 is connected to the current pulse width modulation signal Ipwn, the second terminal of the third filtering resistor R33 is connected to the first terminal of the third filtering capacitor C19 and outputs the current adjustment signal Iset, and the second terminal of the third filtering capacitor C19 is connected to ground.

[0045] Please refer to Figure 3 In another embodiment, the second filtering module 30 includes a third filtering resistor R33, a fourth filtering resistor R32, a third filtering capacitor C19, and a fourth filtering capacitor C18.

[0046] The first terminal of the third filter resistor R33 is connected to the current pulse width modulation signal Ipwn. The second terminal of the third filter resistor R33 is connected to the first terminal of the third filter capacitor C19 and the first terminal of the fourth filter resistor R32. The second terminal of the fourth filter resistor R32 outputs the current adjustment signal Iset and is connected to the first terminal of the fourth filter capacitor C18. The second terminals of the third filter capacitor C19 and the fourth filter capacitor C18 are both grounded to SGND.

[0047] The filter circuit, consisting of the third filter resistor R33, the fourth filter resistor R32, the third filter capacitor C19, and the fourth filter capacitor C18, filters the externally input current pulse width modulation signal Ipwn to output a DC current adjustment signal Iset. The constant current value of the transformer's output current Iout1 is then adjusted through the current adjustment signal Iset.

[0048] In this embodiment, the first input terminal of the voltage closed-loop control module is connected to the voltage output terminal of the transformer, the second input terminal of the voltage closed-loop control module is connected to the reference voltage, the third input terminal of the voltage closed-loop control module is connected to the output terminal of the first filter module, and the voltage closed-loop control module outputs a constant voltage regulation signal. Please continue to refer to this. Figure 1 and Figure 2 The voltage closed-loop control module 40 includes a voltage divider circuit 41 and a second operational amplifier circuit 42.

[0049] The input terminal of the voltage divider circuit 41 is connected to the output voltage Vout1 of the transformer as the first input terminal of the voltage closed-loop control module 40, and the output terminal of the voltage divider circuit 41 outputs the divided voltage. The first input terminal of the second operational amplifier circuit 42 is connected to the second input terminal of the voltage closed-loop control module 40, and the first input terminal of the second operational amplifier circuit 42 is also connected to the third input terminal of the voltage closed-loop control module 40. The second input terminal of the second operational amplifier circuit 42 is connected to the output terminal of the voltage divider circuit 41, and the output terminal of the second operational amplifier circuit 42 outputs the constant voltage regulation signal V1.

[0050] Please continue to refer to this. Figure 1 and Figure 2 The voltage divider circuit 41 specifically includes a first voltage acquisition resistor R5, a second voltage acquisition resistor R10, a third voltage acquisition resistor R21, and a fourth voltage acquisition resistor R20.

[0051] The second operational amplifier circuit 42 specifically includes a first input resistor R14, a second input resistor R7, a second feedback resistor R24, a second output resistor R17, and a second operational amplifier amp2.

[0052] The first terminal of the first voltage acquisition resistor R5 is connected to the output voltage Vout1 of the transformer. The second terminal of the first voltage acquisition resistor R5 is connected to the first terminal of the second voltage acquisition resistor R10. The second terminal of the second voltage acquisition resistor R10 is connected to the first terminal of the third voltage acquisition resistor R21, the first terminal of the fourth voltage acquisition resistor R20, and the inverting input terminal of the second operational amplifier amp2. The second terminals of the third voltage acquisition resistor R21 and the fourth voltage acquisition resistor R20 are both connected to ground SGND. The first terminal of the first input resistor R14 is connected to the reference voltage Vref. The second terminal of the first input resistor R14 is connected to the non-inverting input terminal of the second operational amplifier amp2 and the second terminal of the second input resistor R7. The first terminal of the second input resistor R7 is connected to the voltage regulation signal Vset. The first terminal of the second feedback resistor R24 ​​is connected to the inverting input terminal of the second operational amplifier amp2. The second terminal of the second feedback resistor R24 ​​is connected to the output terminal of the second operational amplifier amp2 and the first terminal of the second output resistor R17. The second terminal of the second output resistor R17 outputs the constant voltage regulation signal V1.

[0053] In this embodiment, the first input terminal of the current closed-loop control module is connected to the output terminal of the current acquisition and amplification module, the second input terminal of the current closed-loop control module is connected to the reference current, the third input terminal of the current closed-loop control module is connected to the output terminal of the second filtering module, and the current closed-loop control module outputs a constant current regulation signal. Please continue to refer to this. Figure 1 and Figure 2 The current closed-loop control module 50 includes a third operational amplifier circuit 53, a current filter circuit 51, and a second current compensation circuit 52.

[0054] The input terminal of the current filtering circuit 51 serves as the third input terminal of the voltage closed-loop control module 50, and the output terminal of the current filtering circuit 51 outputs a current adjustment and filtering signal.

[0055] The first input terminal of the third operational amplifier circuit 53 serves as the first input terminal of the current closed-loop control module, the second input terminal of the third operational amplifier serves as the second input terminal of the current closed-loop control module, and the second input terminal of the third operational amplifier circuit 53 is also connected to the output terminal of the current filter circuit 51. The output terminal of the third operational amplifier circuit 53 outputs the constant current control signal V2.

[0056] The first end of the second current compensation circuit 52 is connected to the first input end of the third operational amplifier circuit 53, and the second end of the second current compensation circuit 52 is connected to the output end of the third operational amplifier circuit 53.

[0057] Please continue to refer to this. Figure 1 and Figure 2 The current filtering circuit 51 specifically includes a sixth filtering resistor R30, a ninth filtering capacitor C14, and a tenth filtering capacitor C11.

[0058] The third operational amplifier circuit 53 specifically includes a third operational amplifier amp3 and a third output resistor R26.

[0059] The second current compensation circuit 52 specifically includes a sixth compensation resistor R27, a seventh compensation resistor R31, a first compensation capacitor C15, a second compensation capacitor C17, and a third compensation capacitor C16.

[0060] The first terminal of the sixth compensation resistor R27 is connected to the reference current Iref. The second terminal of the sixth compensation resistor R27 is connected to the non-inverting input terminal of the third operational amplifier amp3, the second terminal of the sixth filter resistor R30, and the first terminal of the ninth filter capacitor C14. The first terminal of the sixth filter resistor R30 is connected to the current adjustment signal Iset. The second terminal of the ninth filter capacitor C14 is connected to ground SGND. The inverting input terminal of the third operational amplifier amp3 is connected to the acquisition and amplification current Iout2 and the first terminal of the first compensation capacitor C15. The second terminal of the first compensation capacitor C15 is connected to the output terminal of the third operational amplifier amp3. The first ends of the second compensation capacitor C17 are respectively connected to the first ends of the first compensation capacitor C15 and the third compensation capacitor C16. The second end of the second compensation capacitor C17 is connected to the first end of the seventh compensation resistor R31. The second end of the seventh compensation resistor R31 is connected to the second end of the first compensation capacitor C15. The second end of the third compensation capacitor C16 is connected to the ground SGND. The tenth filter capacitor C11 is coupled between the non-inverting input and the inverting input of the third operational amplifier amp3. The first end of the third output resistor R26 is connected to the output of the third operational amplifier amp3. The second end of the third output resistor R26 outputs the constant current control signal V2.

[0061] The first compensation capacitor C15, the second compensation capacitor C17, the third compensation capacitor C16, and the seventh compensation resistor R31 are used for feedback compensation of the third operational amplifier amp3, and the sixth compensation resistor R27 is used for compensation of the input signal of the third operational amplifier amp3. The ninth filter capacitor C14 and the sixth filter resistor R30 are used to filter the current adjustment signal Iset, and the tenth filter capacitor C11 is used to filter the noise between the inverting input terminal and the non-inverting input terminal of the third operational amplifier amp3, thereby greatly improving the accuracy of the constant current control signal V2.

[0062] In this embodiment, the first input terminal of the constant current and constant voltage regulation module is connected to the voltage closed-loop control module, the second input terminal of the constant current and constant voltage regulation module is connected to the current closed-loop control module, and the output terminal of the constant current and constant voltage regulation module is connected to the primary winding of the transformer, so as to regulate the constant voltage value of the output voltage according to the constant voltage regulation signal, and regulate the constant current value of the output current according to the constant current regulation signal.

[0063] Please continue to refer to this. Figure 1 and Figure 2 The constant current and constant voltage regulation module 60 includes a first isolation diode D1, a second isolation diode D2, a first regulating resistor R25, and an optocoupler regulator L1. The cathode of the first isolation diode D1 is connected to the constant voltage regulation signal V1, and the anode of the first isolation diode D1 is connected to the first terminal of the optocoupler regulator L1. The cathode of the second isolation diode D2 is connected to the constant current regulation signal V2, and the anode of the second isolation diode D2 is connected to the first terminal of the optocoupler regulator L1. The first terminal of the first regulating resistor R25 is connected to the power supply voltage VDD, and the second terminal of the first regulating resistor R25 is connected to the second terminal of the optocoupler regulator L1. The optocoupler regulator L1 controls the input voltage Vin of the primary winding of the transformer according to the constant voltage regulation signal V1 to regulate the constant voltage value of the output voltage Vout1 of the secondary winding of the transformer. The optocoupler regulator L1 also controls the input voltage Vin of the primary winding of the transformer according to the constant current regulation signal V2 to regulate the constant current value of the output current Iout1 of the secondary winding of the transformer.

[0064] Since the optocoupler regulator L1 controls the input voltage Vin of the primary winding of the transformer according to the constant voltage regulation signal V1, and controls the input voltage Vin of the primary winding of the transformer according to the constant current regulation signal V2, both of these are conventional techniques in the field and will not be described in detail here.

[0065] Please refer to Figure 3In another embodiment, the current acquisition and amplification module 10 further includes a first current compensation circuit 13, the first terminal of the first current compensation circuit 13 being connected to the reference voltage Vref, the second terminal of the first current compensation circuit 13 being connected to ground, the third terminal of the first current compensation circuit 13 being connected to the first input terminal of the first operational amplifier circuit 12, and the fourth terminal of the first current compensation circuit 13 being connected to the second input terminal of the first operational amplifier circuit 12.

[0066] Please continue to refer to this. Figure 3 The first current compensation circuit 13 specifically includes a first compensation resistor R2, a second compensation resistor R6, a third compensation resistor R3, a fourth compensation resistor R13, and a fifth compensation resistor R18.

[0067] Please continue to refer to this. Figure 3 The current acquisition and amplification module 10 also includes a fifth filter capacitor C2, a sixth filter capacitor C6, a seventh filter capacitor C9, an eighth filter capacitor C1, an eleventh filter capacitor C5, and a fifth filter resistor R16.

[0068] The first terminal of the first compensation resistor R2 is connected to the reference voltage Vref. The second terminal of the first compensation resistor R2 is connected to the first terminal of the second compensation resistor R6 and the first terminal of the third compensation resistor R3. The second terminal of the third compensation resistor R3 is connected to the first terminal of the fifth filter capacitor C2 and the ground SGND. The second terminal of the second compensation resistor R6 is connected to the second terminal of the third current acquisition resistor R9 and the first terminal of the fourth compensation resistor R13. The second terminal of the fifth filter capacitor C2 is connected to the first terminal of the third current acquisition resistor R9. The second terminal of the fourth compensation resistor R13 is connected to the first terminal of the fifth compensation resistor R18 and the ground SGND. The reference voltage Vref; the second terminal of the fifth compensation resistor R18 is connected to the second terminal of the fourth current acquisition resistor R23; the first terminal of the sixth filter capacitor C6 is connected to the first terminal of the first current acquisition resistor R12, and the second terminal of the sixth filter capacitor C6 is connected to the first terminal of the second current acquisition resistor R19; the first terminal of the seventh filter capacitor C9 is connected to the second terminal of the second current acquisition resistor R19, and the second terminal of the seventh filter capacitor C9 is connected to ground SGND; the first terminal of the eighth filter capacitor C1 is connected to the ground SGND of the first operational amplifier amp1, and the second terminal of the eighth filter capacitor C1 is connected to the power supply voltage VDD. The first terminal of the eleventh filter capacitor C5 is connected to the output terminal of the first operational amplifier amp1 and the first terminal of the fifth filter resistor R16, and the second terminals of the eleventh filter capacitor C5 and the fifth filter resistor R16 are both connected to ground SGND.

[0069] The first compensation resistor R2, the second compensation resistor R6, the third compensation resistor R3, the fourth compensation resistor R13, and the fifth compensation resistor R18 constitute the compensation circuit of the first operational amplifier amp1 to correct the bias voltage of the first operational amplifier amp1, thereby improving the accuracy of the acquired amplified current Iout2. The fifth filter capacitor C2, the sixth filter capacitor C6, the seventh filter capacitor C9, and the eighth filter capacitor C1 constitute the noise filtering network of the first operational amplifier amp1 to filter the first differential signal Iout1+ and the second differential signal Iout1- of the output current, as well as the ground terminal SGND of the first operational amplifier amp1. The eleventh filter capacitor C5 and the fifth filter resistor R16 form an RC filter structure to filter the output signal of the first operational amplifier amp1, thereby improving the accuracy of the acquired amplified current Iout2.

[0070] Please continue to refer to this. Figure 3 In another embodiment, the voltage closed-loop control module 40 further includes a first overcharge protection resistor R4, a first overcharge protection capacitor C3, and a second overcharge protection capacitor C4; the first end of the first overcharge protection resistor R4 is connected to the first end of the first voltage acquisition resistor R5, the second end of the first overcharge protection resistor R4 is connected to the first end of the first overcharge protection capacitor C3, the second end of the first overcharge protection capacitor C3 is connected to the first end of the second overcharge protection capacitor C4, and the second end of the second overcharge protection capacitor C4 is connected to the second end of the second voltage acquisition resistor R10.

[0071] The first overcharge protection resistor R4, the first overcharge protection capacitor C3, and the second overcharge protection capacitor C4 constitute an output voltage overload control circuit to prevent the output voltage Vout1 from overcharging when the charger is turned on.

[0072] Please continue to refer to this. Figure 3 In another embodiment, the voltage closed-loop control module 40 further includes a feedback capacitor C10, an input filter capacitor C7, and an input diode D2.

[0073] The first terminal of the feedback capacitor C10 is connected to the inverting input terminal of the second operational amplifier amp2, and the second terminal of the feedback capacitor C10 is connected to the first terminal of the second feedback resistor R24. The first terminal of the input filter capacitor C7 is connected to the non-inverting input terminal of the second operational amplifier amp2, and the second terminal of the input filter capacitor C7 is connected to ground SGND. The anode of the input diode D2 is connected to the non-inverting input terminal of the second operational amplifier amp2, and the cathode of the input diode D2 is connected to the first terminal of the first input resistor R14. Please refer to [reference needed]. Figure 4In another embodiment, the circuit for generating the reference voltage Vref includes a reference resistor R15, a reference capacitor C8, and a Zener diode U2. The first terminal of the reference resistor R15 is connected to the power supply voltage VDD, and the second terminal of the reference resistor R15 outputs the reference voltage Vref. Furthermore, the second terminal of the reference resistor R15 is connected to the first terminal of the reference capacitor C8 and the cathode of the Zener diode U2. The anode of the Zener diode U2 and the second terminal of the reference capacitor C8 are both connected to ground SGND.

[0074] In summary, the constant voltage and constant current control circuit provided in this embodiment includes a voltage closed-loop control module that outputs a constant voltage control signal based on the acquired voltage and reference voltage of the transformer output voltage, and adjusts the magnitude of the constant voltage control signal by filtering the externally input voltage pulse width modulation signal using a first filtering module. A current closed-loop control module outputs a constant current control signal based on the acquired and amplified current obtained from the transformer output current acquired and amplified by a current acquisition and amplification module, and the reference current, and adjusts the magnitude of the constant current control signal by filtering the externally input current pulse width modulation signal using a second filtering module. The constant current and constant voltage control module adjusts the constant voltage value of the output voltage and the constant current value of the output current based on the constant voltage control signal.

[0075] Furthermore, the first compensation resistor, the second compensation resistor, the third compensation resistor, the fourth compensation resistor, and the fifth compensation resistor constitute the compensation circuit of the first operational amplifier to correct the bias voltage of the first operational amplifier, thereby improving the accuracy of the acquired amplified current. The fifth filter capacitor, the sixth filter capacitor, the seventh filter capacitor, and the eighth filter capacitor constitute the noise filtering network of the first operational amplifier to filter the first differential signal and the second differential signal of the output current, as well as the ground terminal of the first operational amplifier.

[0076] Furthermore, the first overcharge protection resistor, the first overcharge protection capacitor, and the second overcharge protection capacitor work together to prevent the output voltage from overcharging when the charger is turned on.

[0077] Furthermore, the first compensation capacitor, the second compensation capacitor, the third compensation capacitor, and the seventh compensation resistor are used to provide feedback compensation for the third operational amplifier, and the sixth compensation resistor is used to compensate the input signal of the third operational amplifier. The ninth filter capacitor and the sixth filter resistor are used to filter the current adjustment signal, and the tenth filter capacitor is used to filter the noise between the inverting input terminal and the non-inverting input terminal of the third operational amplifier.

[0078] The inventors' embodiments also provide a circuit system including the constant voltage and constant current control circuit provided in the above embodiments.

[0079] The inventors' embodiments also provide an electronic device including the circuit system provided in the above embodiments.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A constant voltage and constant current control circuit, characterized in that, The constant voltage and constant current control circuit includes: A current acquisition and amplification module is provided, wherein the input terminal of the current acquisition and amplification module is connected to the current output terminal of the transformer, and the output terminal of the current acquisition and amplification module outputs an acquisition and amplification current, which is formed by acquiring and amplifying the output current of the current output terminal of the transformer. The first filtering module has an input terminal connected to an externally input voltage pulse width modulation signal and an output terminal outputting a voltage adjustment signal, which is formed based on the filtered voltage pulse width modulation signal. The second filtering module has an input terminal connected to an externally input current pulse width modulation signal and an output terminal outputting a current adjustment signal, which is formed based on the filtered current pulse width modulation signal. A voltage closed-loop control module, wherein the first input terminal of the voltage closed-loop control module is connected to the voltage output terminal of the transformer, the second input terminal of the voltage closed-loop control module is connected to the reference voltage, the third input terminal of the voltage closed-loop control module is connected to the output terminal of the first filter module, and the voltage closed-loop control module outputs a constant voltage regulation signal. A current closed-loop control module, wherein the first input terminal of the current closed-loop control module is connected to the output terminal of the current acquisition and amplification module, the second input terminal of the current closed-loop control module is connected to the reference current, the third input terminal of the current closed-loop control module is connected to the output terminal of the second filter module, and the current closed-loop control module outputs a constant current regulation signal. A constant current and constant voltage regulation module is provided. The first input terminal of the constant current and constant voltage regulation module is connected to the voltage closed-loop control module, the second input terminal of the constant current and constant voltage regulation module is connected to the current closed-loop control module, and the output terminal of the constant current and constant voltage regulation module is connected to the primary winding of the transformer. The constant voltage regulation module regulates the constant voltage value of the output voltage according to the constant voltage regulation signal, and regulates the constant current value of the output current according to the constant current regulation signal.

2. The constant voltage and constant current control circuit according to claim 1, characterized in that, The first filtering module includes: a first filtering resistor and a first filtering capacitor; the first end of the first filtering resistor is connected to the voltage pulse width modulation signal, the second end of the first filtering resistor is connected to the first end of the first filtering capacitor and outputs the voltage adjustment signal, and the second end of the first filtering capacitor is connected to ground.

3. The constant voltage and constant current control circuit according to claim 2, characterized in that, The first filtering module further includes: a second filtering resistor and a second filtering capacitor; the first end of the second filtering resistor is connected to the second end of the first filtering resistor, the second end of the second filtering resistor is connected to the first end of the second filtering capacitor and outputs the voltage regulation signal, and the second end of the second filtering capacitor is also connected to ground.

4. The constant voltage and constant current control circuit according to claim 1, characterized in that, The second filtering module includes a third filtering resistor and a third filtering capacitor; the first end of the third filtering resistor is connected to the current pulse width modulation signal, the second end of the third filtering resistor is connected to the first end of the third filtering capacitor and outputs the current adjustment signal, and the second end of the third filtering capacitor is connected to ground.

5. The constant voltage and constant current control circuit according to claim 4, characterized in that, The second filtering module further includes: a fourth filtering resistor and a fourth filtering capacitor; the first end of the fourth filtering resistor is connected to the second end of the third filtering resistor, the second end of the fourth filtering resistor is connected to the first end of the fourth filtering capacitor and outputs the current adjustment signal, and the second end of the fourth filtering capacitor is connected to ground.

6. The constant voltage and constant current control circuit according to claim 1, characterized in that, The current acquisition and amplification module includes: an acquisition circuit and a first operational amplifier circuit; The first input terminal of the acquisition circuit is connected to the first port of the current output terminal of the transformer, the second input terminal of the acquisition circuit is connected to the second port of the current output terminal of the transformer, the first output terminal of the acquisition circuit outputs the first differential signal of the acquisition current, and the second output terminal of the acquisition circuit outputs the second differential signal of the acquisition current. The first input terminal of the first operational amplifier circuit is connected to the first output terminal of the acquisition circuit, the second input terminal of the first operational amplifier circuit is connected to the second output terminal of the acquisition circuit, and the output terminal of the first operational amplifier circuit outputs the acquisition amplification current.

7. The constant voltage and constant current control circuit according to claim 6, characterized in that, The current acquisition and amplification module further includes a first current compensation circuit. The first terminal of the first current compensation circuit is connected to the reference voltage, the second terminal of the first current compensation circuit is connected to ground, the third terminal of the first current compensation circuit is connected to the first input terminal of the first operational amplifier circuit, and the fourth terminal of the first current compensation circuit is connected to the second input terminal of the first operational amplifier circuit.

8. The constant voltage and constant current control circuit according to claim 1, characterized in that, The voltage closed-loop control module includes a voltage divider circuit and a second operational amplifier circuit. The input terminal of the voltage divider circuit is connected to the output voltage of the transformer as the first input terminal of the voltage closed-loop control module, and the output terminal of the voltage divider circuit outputs the divided voltage. The first input terminal of the second operational amplifier circuit serves as the second input terminal of the voltage closed-loop control module, and also serves as the third input terminal of the voltage closed-loop control module. The second input terminal of the second operational amplifier circuit is connected to the output terminal of the voltage divider circuit, and the output terminal of the second operational amplifier circuit outputs the constant voltage regulation signal.

9. The constant voltage and constant current control circuit according to claim 8, characterized in that, The voltage closed-loop control module further includes a first overcharge protection resistor, a first overcharge protection capacitor, and a second overcharge protection capacitor; the first end of the first overcharge protection resistor is connected to the first end of the first voltage acquisition resistor, the second end of the first overcharge protection resistor is connected to the first end of the first overcharge protection capacitor, the second end of the first overcharge protection capacitor is connected to the first end of the second overcharge protection capacitor, and the second end of the second overcharge protection capacitor is connected to the second end of the second voltage acquisition resistor.

10. The constant voltage and constant current control circuit according to claim 1, characterized in that, The current closed-loop control module includes a third operational amplifier circuit, a current filter circuit, and a second current compensation circuit. The input terminal of the current filtering circuit serves as the third input terminal of the voltage closed-loop control module, and the output terminal of the current filtering circuit outputs a current adjustment and filtering signal. The first input terminal of the third operational amplifier circuit serves as the first input terminal of the current closed-loop control module, the second input terminal of the third operational amplifier circuit serves as the second input terminal of the current closed-loop control module, and the second input terminal of the third operational amplifier circuit is also connected to the output terminal of the current filter circuit. The output terminal of the third operational amplifier circuit outputs the constant current control signal. The first terminal of the second current compensation circuit is connected to the first input terminal of the third operational amplifier circuit, and the second terminal of the second current compensation circuit is connected to the output terminal of the third operational amplifier circuit.

11. The constant voltage and constant current control circuit according to claim 1, characterized in that, The constant current and constant voltage regulation module includes a first isolation diode, a second isolation diode, a first regulating resistor, and an optocoupler regulator. The cathode of the first isolation diode is connected to the constant voltage regulation signal, and the anode of the first isolation diode is connected to the first terminal of the optocoupler regulator. The cathode of the second isolation diode is connected to the constant current regulation signal, and the anode of the second isolation diode is connected to the first terminal of the optocoupler regulator. The first terminal of the first regulating resistor is connected to the power supply voltage, and the second terminal of the first regulating resistor is connected to the second terminal of the optocoupler regulator. The optocoupler regulator controls the input voltage of the primary winding of the transformer according to the constant voltage regulation signal to regulate the constant voltage value of the output voltage of the secondary winding of the transformer. The optocoupler regulator also controls the input voltage of the primary winding of the transformer according to the constant current regulation signal to regulate the constant current value of the output current of the secondary winding of the transformer.

12. A circuit system, characterized in that, The circuit system includes the constant voltage and constant current control circuit according to any one of claims 1 to 11.

13. An electronic device, characterized in that, The electronic device includes the circuit system of claim 12.

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