Charging control circuit

Abstract

The utility model discloses a charging control circuit. The charging control circuit comprises an output module, a voltage control loop, a current control loop and a control module. The control module is coupled with the output module and is configured to receive the output current and the output voltage of the output module; the first input end of the voltage control loop is used for receiving the power supply voltage of the output module, and the second input end is coupled with the first output pin of the control module; the first input end of the current control loop is coupled to the second output pin of the control module, the second input end of the current control loop is coupled to the third output pin of the control module, and the control module is configured to provide a value representing the output current to the first input end of the current control loop; wherein the control module is used for reducing the value at the second input end of the voltage control loop and / or increasing the value at the first input end of the current control loop. The charging control circuit provided by the utility model can be prevented from being damaged by hot plug operation.

Description

Technical Field

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

[0002] During charging, especially in constant current mode, if a hot-plugging operation (i.e., plugging or unplugging the output cable while it is energized) is suddenly performed on the charging control circuit, the internal output voltage will rise sharply due to the insufficient response of the voltage control loop. This can easily generate a large voltage spike, causing instantaneous voltage or current surges to the internal components, thus damaging the charging control circuit. Since the time from unplugging to the appearance of the voltage spike occurs within an extremely short period (typically a few milliseconds or even less than one millisecond), designing a charging control circuit that is immune to damage from hot-plugging operations is particularly important. Utility Model Content

[0003] This invention provides a charging control circuit that can be protected from damage caused by hot-plugging operations.

[0004] This utility model embodiment provides a charging control circuit, including: an output module, a voltage control loop, a current control loop, and a control module; the control module is coupled to the output module and configured to receive the output current and output voltage of the output module; the voltage control loop has a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal is used to receive the supply voltage of the output module, and the second input terminal is coupled to the first output pin of the control module, and the control module is configured to provide a reference voltage to the second input terminal of the voltage control loop; the current control loop has a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal is coupled to the second output pin of the control module, and the second input terminal is coupled to the third output pin of the control module, and the control module is configured to provide a value representing the output current to the first input terminal of the current control loop and to provide a reference current to the second input terminal of the current control loop; wherein the control module is used to pull down the value at the second input terminal of the voltage control loop and / or pull up the value at the first input terminal of the current control loop.

[0005] Optionally, the voltage control loop includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, and a second capacitor; the first terminal of the first resistor is used to receive the power supply voltage of the output module, and the second terminal of the first resistor is connected to the first terminal of the second resistor and the first terminal of the third resistor; the second terminal of the second resistor is connected to the first input terminal of the first operational amplifier, and the second terminal of the third resistor is grounded; the first terminal of the fourth resistor is connected to the first output pin of the control module, and the second terminal of the fourth resistor is connected to the second input terminal of the first operational amplifier and the first terminal of the first capacitor, and the second terminal of the first capacitor is grounded; the first terminal of the second capacitor is connected to the first input terminal of the first operational amplifier, the second terminal of the second capacitor is connected to the first terminal of the fifth resistor, and the second terminal of the fifth resistor is connected to the output terminal of the first operational amplifier.

[0006] Optionally, the current control loop includes a second operational amplifier, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, and a fourth capacitor; the first terminal of the sixth resistor is connected to the first input terminal of the second operational amplifier, the second terminal of the sixth resistor is connected to the first terminal of the seventh resistor, and the second terminal of the seventh resistor is connected to the second output pin of the control module; the first terminal of the eighth resistor is connected to the third output pin of the control module, the second terminal of the eighth resistor is connected to the second input terminal of the second operational amplifier and the first terminal of the third capacitor, and the second terminal of the third capacitor is grounded; the first terminal of the fourth capacitor is connected to the first input terminal of the second operational amplifier, the second terminal of the fourth capacitor is connected to the first terminal of the ninth resistor, and the second terminal of the ninth resistor is connected to the output terminal of the second operational amplifier.

[0007] Optionally, the control module also has a fourth output pin, which is coupled to the second input of the voltage control loop. The control module is used to provide a low-level voltage control signal to the second input of the voltage control loop and / or pull down the reference voltage.

[0008] Optionally, the control module also has a fifth output pin, which is coupled to the first input of the current control loop. The control module is used to provide a high-level current control signal to the first input of the current control loop.

[0009] Optionally, the control module is also used to pull down the reference current.

[0010] Optionally, the output module includes a switching circuit and a voltage conversion unit; the voltage conversion unit is coupled to the output terminals of the voltage control loop and the current control loop, and the voltage conversion unit is also coupled to the switching circuit.

[0011] Optionally, the voltage conversion unit includes an optocoupler and an AC / DC power converter; the input terminal of the optocoupler is connected to the output terminal of the voltage control loop and the current control loop, the output terminal of the optocoupler is connected to the enable pin or feedback pin of the AC / DC power converter, and the output terminal of the AC / DC power converter is connected to the switching circuit to provide power supply voltage to the switching circuit.

[0012] Optionally, the switching circuit includes a switching transistor, a fifth capacitor, a tenth resistor, an eleventh resistor, and a sampling resistor; the first terminal of the fifth capacitor is connected to the first output terminal of the AC / DC power converter, and the second terminal of the fifth capacitor is connected to the second output terminal of the AC / DC power converter and the first terminal of the sampling resistor; the gate of the switching transistor is connected to the control module, the first terminal of the switching transistor is connected to the first terminal of the fifth capacitor, and the second terminal of the switching transistor is connected to the positive output terminal of the switching circuit; the first terminal of the tenth resistor is connected to the second terminal of the switching transistor, the second terminal of the tenth resistor is connected to the first terminal of the eleventh resistor, the second terminal of the eleventh resistor is connected to the first terminal of the sampling resistor, and the second terminal of the sampling resistor is connected to the negative output terminal of the switching circuit.

[0013] Optionally, the control module is also used to adjust the reference voltage at the second input terminal of the voltage control loop to be greater than the output voltage, and to adjust the difference between the reference voltage and the output voltage to a preset value.

[0014] The charging control circuit provided in this embodiment includes an output module, a voltage control loop, a current control loop, and a control module. The control module collects the output voltage and output current of the output module, and when the changes in output voltage and / or output current meet preset conditions, it lowers the value at the second input terminal of the voltage control loop and / or raises the value at the first input terminal of the current control loop to control the output module to stop working. This can promptly respond to and control the voltage rise sharply after the output interface of the charging control circuit is hot-plugged, eliminate or reduce the possibility of voltage spikes at the output interface of the charging control circuit, reduce the stress on electronic components, and thus reduce the risk of damage to the charging control circuit due to hot-plugging operations, thereby improving the safety and reliability of the charging control circuit.

[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a charging control circuit provided in an embodiment of the present invention;

[0018] Figure 2 The provided diagram is a schematic diagram of the voltage control loop in one embodiment;

[0019] Figure 3 The provided diagram is a schematic diagram of the current control loop in one embodiment;

[0020] Figure 4 This is a schematic diagram of another charging control circuit provided in this embodiment of the utility model;

[0021] Figure 5 This is a schematic diagram of another charging control circuit provided in this embodiment of the utility model;

[0022] Figure 6 This is a flowchart illustrating the working process of a charging control circuit provided in an embodiment of this utility model;

[0023] Figure 7 This is a measurement diagram of the output voltage waveform of the charging control circuit during the hot-plugging and unplugging process of related technologies;

[0024] Figure 8 This is a measurement diagram of the output voltage waveform during the hot-plugging and unplugging process of the charging control circuit provided in this embodiment of the utility model. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. 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 should fall within the protection scope of the present invention.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model 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 the embodiments of the utility model 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 non-exclusive inclusion. The term "based on" means "at least partially based on." The term "one embodiment" means "at least one embodiment." The term "coupled" indicates that it can be a direct connection or an indirect connection.

[0027] Figure 1 This is a schematic diagram of a charging control circuit provided in an embodiment of this utility model. Figure 1 As shown, the charging control circuit includes: an output module 10, a voltage control loop 20, a current control loop 30, and a control module 40.

[0028] The control module 40 is coupled to the output module 10 and configured to receive the output current and output voltage of the output module 10.

[0029] The voltage control loop 20 has a first input terminal, a second input terminal, and an output terminal. Its first input terminal is used to receive the power supply voltage V1 of the output module 10, and its second input terminal is coupled to the first output pin of the control module 40. The control module 40 is configured to provide a reference voltage V-Ctrl to the second input terminal of the voltage control loop 20.

[0030] The current control loop 30 has a first input terminal, a second input terminal, and an output terminal. Its first input terminal is coupled to the second output pin of the control module 40, and its second input terminal is coupled to the third output pin of the control module 40. The control module 40 is configured to provide a value representing the output current at the first input terminal of the current control loop 30, and to provide a reference current I-Ctrl at the second input terminal of the current control loop 30.

[0031] The control module 40 is used to pull down the value at the second input terminal of the voltage control loop 20 and / or pull up the value at the first input terminal of the current control loop 30.

[0032] Specifically, the output module 10 is the final output part of the charging control circuit, which provides power to external loads or charging devices.

[0033] The voltage control loop 20 is used to regulate the output voltage of the output module 10. It compares the sampled feedback voltage of the output module 10 with the reference voltage V-Ctrl provided by the control module 40, and adjusts the output voltage based on the comparison result to maintain it near a stable value set by the voltage division ratio of the reference voltage. If the feedback voltage of the output voltage is higher than the reference voltage, i.e., the actual output voltage is higher than the set output voltage value of the reference voltage, the voltage control loop 20 will cause the output module 10 to decrease the output voltage through the feedback signal; conversely, if the feedback voltage of the output voltage is lower than the reference voltage, the voltage control loop 20 will cause the output module 10 to increase the output voltage through the feedback signal. In one embodiment, the voltage control loop 20 can regulate the output voltage by providing a feedback signal to the AC / DC power converter 1022 through the optocoupler 1021, etc., to ensure that the output voltage is stable at the level set by the reference voltage.

[0034] The current control loop 30 is used to regulate the output current of the output module 10. By comparing the output current of the output module 10 with the set value of the reference current I-Ctrl provided by the control module 40, the output current is adjusted according to the comparison result to keep it near the desired output current set by the reference current. If the feedback voltage formed after sampling the output current is higher than the reference voltage provided by the reference current I-Ctrl, i.e., the actual output current is higher than the set output current value, the current control loop 30 will reduce the output current of the output module 10 through the feedback signal; conversely, if the feedback voltage formed after sampling the output current is lower than the reference voltage provided by the reference current I-Ctrl, the current control loop 30 will increase the output current of the output module 10 through the feedback signal. In one embodiment, the current control loop 30 can regulate the output current by providing a feedback signal to the AC / DC power converter 1022 through the optocoupler 1021, etc., to ensure that the output current is stable at the value set by the reference current.

[0035] The control module 40 may include a microcontroller. Optionally, the control module 40 may include a microcontroller, or a digital signal processor (DSP) or a field-programmable gate array (FPGA).

[0036] In one embodiment, the control module 40 can acquire the output voltage and output current of the output module 10 and control the output module 10 to output a constant current through the current control loop 30 or to output a constant voltage through the voltage control loop 20. That is, the output mode of the charging control circuit can be either a constant current output mode or a constant voltage output mode.

[0037] In one embodiment, when the load is a constant input voltage load, the user can select a constant voltage output mode. When the load is a constant current input load, the user can select a constant current output mode.

[0038] In one embodiment, for example, the load may be an electric vehicle battery.

[0039] In one embodiment, during the initial charging phase, the output voltage is low, and the charging control circuit charges the load in a constant current output mode. The current control loop 30 ensures the output current remains stable at the value set by the reference current I-Ctrl, preventing excessive current from damaging the load and improving charging efficiency. As charging progresses, the output voltage gradually increases, but the output current remains constant until the output voltage reaches a preset constant voltage threshold. When the output voltage reaches the set constant voltage threshold, the charging control circuit switches to constant voltage output mode. At this time, the voltage control loop 20 controls the output voltage to remain stable at the value set by the reference voltage V-Ctrl, while the output current gradually decreases as the battery saturates until it reaches the cutoff current, indicating that charging is complete.

[0040] In one embodiment, when the rise in output voltage exceeds a first set value within a set time period, the control module 40 determines that a hot-plugging action has occurred at the output interface of the charging control circuit. At this time, the control module 40 either lowers the value at the second input terminal of the voltage control loop 20, or raises the value at the first input terminal of the current control loop 30, or both lowers the value at the second input terminal of the voltage control loop 20 and raises the value at the first input terminal of the current control loop 30, to control the output module 10 to stop working. In one embodiment, the voltage control loop 20 or the current control loop 30 can provide a stop feedback signal to the AC / DC power converter 1022 via the optocoupler 1021 to stop the output module 10 from working.

[0041] In another embodiment, when the decrease in output current exceeds a second set value within a set time period, the control module 40 determines that a hot-plugging action has occurred at the output interface of the charging control circuit. At this time, the control module 40 either lowers the value at the second input terminal of the voltage control loop 20, or raises the value at the first input terminal of the current control loop 30, or both lowers the value at the second input terminal of the voltage control loop 20 and raises the value at the first input terminal of the current control loop 30, to control the output module 10 to stop working. In one embodiment, the voltage control loop 20 or the current control loop 30 can provide a stop feedback signal to the AC / DC power converter 1022 via the optocoupler 1021 to stop the output module 10 from working.

[0042] In another embodiment, when the rise of the output voltage exceeds a first set value and the fall of the output current exceeds a second set value within a set time period, the control module 40 determines that a hot-plugging action has occurred at the output interface of the charging control circuit. At this time, the control module 40 lowers the value at the second input terminal of the voltage control loop 20, or raises the value at the first input terminal of the current control loop 30, or lowers the value at the second input terminal of the voltage control loop 20 and raises the value at the first input terminal of the current control loop 30, thereby controlling the output module 10 to stop working. In one embodiment, the voltage control loop 20 or the current control loop 30 can provide a stop feedback signal to the AC / DC power converter 1022 via the optocoupler 1021 to stop the output module 10 from working.

[0043] In one embodiment, the control module 40 may provide a low-level voltage control signal to the second input terminal of the voltage control loop 20 to pull down the value at the second input terminal of the voltage control loop 20.

[0044] In another embodiment, the control module 40 can control the reference voltage at the second input terminal of the voltage control loop 20 to be 0, so as to pull down the value at the second input terminal of the voltage control loop 20.

[0045] In another embodiment, the control module 40 may provide a low-level voltage control signal to the second input terminal of the voltage control loop 20 and control the reference voltage of the second input terminal of the voltage control loop 20 to be 0, so as to pull down the value at the second input terminal of the voltage control loop 20.

[0046] In one embodiment, the control module 40 may provide a high-level current control signal to the first input terminal of the current control loop 30 to pull up the value at the first input terminal of the current control loop 30.

[0047] The charging control circuit provided in this embodiment includes an output module 10, a voltage control loop 20, a current control loop 30, and a control module 40. The control module 40 collects the output voltage and output current of the output module 10, and when the changes in the output voltage and / or output current meet preset conditions, it lowers the value at the second input terminal of the voltage control loop 20 and / or raises the value at the first input terminal of the current control loop 30 to control the output module 10 to stop working. This can promptly respond to and control the voltage rise sharply after the output interface of the charging control circuit is hot-plugged, eliminate or reduce the possibility of voltage spikes at the output interface of the charging control circuit, reduce the stress on electronic components, and thus reduce the risk of damage to the charging control circuit due to hot-plugging operations, thereby improving the safety and reliability of the charging control circuit.

[0048] Figure 2This provides a schematic diagram of the voltage control loop in one embodiment. For example... Figure 2 As shown, optionally, the voltage control loop 20 includes a first operational amplifier U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, and a second capacitor C2.

[0049] The first end of the first resistor R1 is used to receive the power supply voltage V1 of the output module 10, and the second end of the first resistor R1 is connected to the first end of the second resistor R2 and the first end of the third resistor R3.

[0050] The second end of the second resistor R2 is connected to the first input terminal of the first operational amplifier U1, and the second end of the third resistor R3 is grounded.

[0051] The first end of the fourth resistor R4 is connected to the first output pin of the control module 40, the second end of the fourth resistor R4 is connected to the second input terminal of the first operational amplifier U1 and the first end of the first capacitor C1, and the second end of the first capacitor C1 is grounded.

[0052] The first terminal of the second capacitor C2 is connected to the first input terminal of the first operational amplifier U1, the second terminal of the second capacitor C2 is connected to the first terminal of the fifth resistor R5, and the second terminal of the fifth resistor R5 is connected to the output terminal of the first operational amplifier U1.

[0053] Specifically, the first resistor R1, the second resistor R2, and the third resistor R3 together divide the supply voltage V1. The divided voltage is sent to the first input terminal of the first operational amplifier U1, thereby providing the first input terminal of the first operational amplifier U1 with the feedback voltage of the output voltage of the output module 10.

[0054] The fourth resistor R4 serves to limit current and also helps stabilize signal transmission.

[0055] The fifth resistor R5 and the second capacitor C2 together form a feedback loop. This feedback loop can feed back the output signal of the first operational amplifier U1 to its first input terminal, thereby adjusting the output of the first operational amplifier U1 to achieve the purpose of stabilizing the output voltage and reducing voltage fluctuations.

[0056] In some implementations, the first terminal of the first resistor R1 serves as the first input terminal of the voltage control loop 20, and the first terminal of the fourth resistor R4 serves as the second input terminal of the voltage control loop 20.

[0057] In some implementations, the first input terminal of the first operational amplifier U1 serves as the first input terminal of the voltage control loop 20, and the second input terminal of the first operational amplifier U1 serves as the second input terminal of the voltage control loop 20.

[0058] Optionally, continue to refer to Figure 2 The voltage control loop 20 also includes a first diode D1, the cathode of which is connected to the output terminal of the first operational amplifier U1, and the anode of which is connected to the output terminal of the voltage control loop 20.

[0059] In some embodiments, when the change in output voltage and / or output current meets a preset condition, the control module 40 pulls down the value at the second input terminal of the voltage control loop 20, causing the voltage at the second input terminal of the first operational amplifier U1 to be less than the voltage at its first input terminal. This causes the first operational amplifier U1 to quickly output a low level, and the first diode D1 to conduct, thereby controlling the output module 10 to stop working and stopping the output voltage from rising. This embodiment achieves this by pulling down the value at the second input terminal of the voltage control loop 20, thereby causing the first operational amplifier U1 to quickly output a low level, thus rapidly responding to hot-plugging actions.

[0060] Figure 3 This provides a schematic diagram of the current control loop in one embodiment. For example... Figure 3 As shown, optionally, the current control loop 30 includes a second operational amplifier U2, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third capacitor C3, and a fourth capacitor C4.

[0061] The first end of the sixth resistor R6 is connected to the first input terminal of the second operational amplifier U2, the second end of the sixth resistor R6 is connected to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is connected to the second output pin of the control module 40.

[0062] The first end of the eighth resistor R8 is connected to the third output pin of the control module 40, the second end of the eighth resistor R8 is connected to the second input terminal of the second operational amplifier U2 and the first end of the third capacitor C3, and the second end of the third capacitor C3 is grounded.

[0063] The first terminal of the fourth capacitor C4 is connected to the first input terminal of the second operational amplifier U2, the second terminal of the fourth capacitor C4 is connected to the first terminal of the ninth resistor R9, and the second terminal of the ninth resistor R9 is connected to the output terminal of the second operational amplifier U2.

[0064] Specifically, the sixth resistor R6 and the seventh resistor R7 work together to divide the signal output from the second output pin of the control module 40 and input it to the first input terminal of the second operational amplifier U2, so as to provide a value representing the output current to the first input terminal of the second operational amplifier U2.

[0065] The eighth resistor R8 serves as a current limiter, transmitting the signal output from the third output pin of the control module 40 to the second input terminal of the second operational amplifier U2.

[0066] The ninth resistor R9 and the fourth capacitor C4 together form a feedback loop, which feeds back the output signal of the second operational amplifier U2 to its first input terminal, so as to adjust the output of the second operational amplifier U2 and achieve precise control of the current.

[0067] The third capacitor C3 can filter out high-frequency noise and interference in the output signal of the third output pin of the control module 40, making the signal input to the second input terminal of the second operational amplifier U2 more stable and pure.

[0068] In some embodiments, the second end of the seventh resistor R7 serves as the first input terminal of the current control loop 30, and the first end of the eighth resistor R8 serves as the second input terminal of the current control loop 30.

[0069] In some embodiments, the first input terminal of the second operational amplifier U1 serves as the first input terminal of the current control loop 30, and the second input terminal of the second operational amplifier U1 serves as the second input terminal of the current control loop 30.

[0070] Optionally, continue to refer to Figure 3 The current control loop 30 also includes a second diode D2. The cathode of the second diode D2 is connected to the output terminal of the second operational amplifier U2, and the anode of the second diode D2 serves as the output terminal of the current control loop 30.

[0071] In some embodiments, when the change in output voltage and / or output current meets a preset condition, the control module 40 raises the value at the first input terminal of the current control loop 30, causing the voltage at the second input terminal of the second operational amplifier U2 to be less than the voltage at its first input terminal. This causes the second operational amplifier U2 to quickly output a low level, and the second diode D2 to conduct, thereby controlling the output module 10 to stop working and stopping the output voltage from rising. This embodiment raises the value at the first input terminal of the current control loop 30, causing the second operational amplifier U2 to quickly output a low level, thus rapidly responding to hot-plugging actions.

[0072] Figure 4 This is a schematic diagram of another charging control circuit provided in an embodiment of this utility model. (See diagram below.) Figure 4 As shown, optionally, the control module 40 also has a fourth output pin, which is coupled to the second input terminal of the voltage control loop 20. The control module 40 is used to provide a low-level voltage control signal V-Pulse to the second input terminal of the voltage control loop 20 and / or pull down the reference voltage V-Ctrl.

[0073] Specifically, when the charging control circuit is working normally, the first input terminal of the first operational amplifier U1 is connected to the voltage divider of the output module 10 (i.e., the sampled value of the output voltage), and the second input terminal normally receives the reference voltage V-Ctrl. When the output voltage is normal in constant voltage mode, the reference voltage V-Ctrl is approximately equal to the output voltage divider, the output of the first operational amplifier U1 is in a balanced state between high and low levels, and the output module 10 works normally.

[0074] In one embodiment, when a hot-plugging action occurs at the output interface of the charging control circuit, the output voltage and / or output current change. When the control module 40 detects that the change in output voltage and / or output current meets a preset condition, it outputs a low-level voltage control signal V-Pulse through the fourth output pin, forcibly pulling down the voltage at the second input terminal of the first operational amplifier U1, making the voltage at the second input terminal of the first operational amplifier U1 less than the voltage at its first input terminal. The first operational amplifier U1 outputs a low level to control the output module 10 to stop working, thereby stopping the output voltage from rising. In this embodiment, by pulling down the voltage at the second input terminal of the first operational amplifier U1, the first operational amplifier U1 quickly outputs a low level, thus rapidly responding to the hot-plugging action.

[0075] In one embodiment, when the control module 40 detects that the change in output voltage and / or output current meets the preset conditions, the control module 40 pulls down the reference voltage V-Ctrl (e.g., the output module 10 controls the reference voltage V-Ctrl to be 0), so that the voltage at the second input terminal of the first operational amplifier U1 is less than the voltage at its first input terminal, and the first operational amplifier U1 outputs a low level to control the output module 10 to stop working, thereby stopping the output voltage from rising.

[0076] In one embodiment, when the control module 40 detects that the change in output voltage and / or output current meets the preset conditions, the control module 40 outputs a low-level voltage control signal V-Pulse through the fourth output pin and pulls down the reference voltage V-Ctrl, so that the voltage at the second input terminal of the first operational amplifier U1 is less than the voltage at its first input terminal, and the first operational amplifier U1 outputs a low level to control the output module 10 to stop working, thereby stopping the output voltage from rising.

[0077] Optionally, continue to refer to Figure 4 The control module 40 also has a fifth output pin, which is coupled to the first input terminal of the current control loop 30. The control module 40 is used to provide a high-level current control signal I-Pulse to the first input terminal of the current control loop.

[0078] Specifically, the fourth and fifth output pins of the control module 40 are normally configured as high-impedance inputs, meaning no external signals are applied.

[0079] When the charging control circuit is working normally, the first input terminal of the second operational amplifier U2 receives the feedback current signal, and the second input terminal normally receives the reference current I-Ctrl. When the output current is normal in constant current mode, the reference current I-Ctrl is approximately equal to the feedback current, and the output of the second operational amplifier U2 is in a balanced state between high and low levels, and the output module 10 works normally.

[0080] In one embodiment, when the control module 40 detects a hot-plugging action at the output interface of the charging control circuit, i.e., when the change in output voltage and / or output current meets a preset condition, it outputs a high-level current control signal I-Pulse through the fifth output pin. This forces the voltage at the first input terminal of the second operational amplifier U2 to rise, causing the reference current I-Ctrl to be less than the feedback current. Consequently, the voltage at the second input terminal of the second operational amplifier U2 is lower than the voltage at its first input terminal. The second operational amplifier U2 then outputs a low-level signal to control the output module 10 to stop working, thereby stopping the output voltage from rising. In this embodiment, by raising the voltage at the first input terminal of the second operational amplifier U2, the second operational amplifier U2 quickly outputs a low-level signal, thus rapidly responding to the hot-plugging action.

[0081] Optionally, the control module 40 is also used to pull down the reference current I-Ctrl. Specifically, when the change in output voltage and / or output current meets a preset condition, the control module 40 pulls down the reference current I-Ctrl (e.g., the output module 10 controls the reference current I-Ctrl to be 0), so that the voltage at the second input terminal of the second operational amplifier U2 is less than the voltage at its first input terminal, and the second operational amplifier U2 outputs a low level to control the output module 10 to stop working, thereby stopping the output voltage from rising.

[0082] In one embodiment, when the change in output voltage and / or output current meets the preset conditions, the control module 40 outputs a high-level current control signal I-Pulse through the fifth output pin and pulls down the reference current I-Ctrl (e.g., the output module 10 controls the reference current I-Ctrl to be 0), so that the voltage at the second input terminal of the second operational amplifier U2 is less than the voltage at its first input terminal, and the second operational amplifier U2 outputs a low level to control the output module 10 to stop working, thereby stopping the output voltage from rising.

[0083] Figure 5 This is a schematic diagram of another charging control circuit provided in an embodiment of this utility model. (See diagram below.) Figure 5 As shown, the output module 10 may optionally include a switching circuit 101 and a voltage conversion unit 102.

[0084] The voltage conversion unit 102 is coupled to the output terminals of the voltage control loop 20 and the current control loop 30, and the voltage conversion unit 102 is also coupled to the switching circuit 101.

[0085] Specifically, the voltage conversion unit 102 is used to convert alternating current (AC) into direct current (DC). The voltage conversion unit 102 can also stop the output voltage according to the output value of the current control loop 30 or the voltage control loop 20.

[0086] In one embodiment, the voltage conversion unit 102 includes an optocoupler 1021 and an AC / DC power converter 1022. The input terminal of the optocoupler 1021 is connected to the output terminals of the voltage control loop 20 and the current control loop 30, and the output terminal of the optocoupler 1021 is connected to the enable pin or feedback pin of the AC / DC power converter 1022. The output terminal of the AC / DC power converter 1022 is connected to the switching circuit 101 to provide a power supply voltage V1 to the switching circuit 101.

[0087] Specifically, optocoupler 1021 provides electrical isolation, safely transmitting the control signal from the low-voltage side (i.e., the output value of voltage control loop 20 or current control loop 30) to the AC / DC power converter 1022 on the high-voltage side. AC / DC power converter 1022 can be a flyback converter, a forward converter, an LLC resonant converter, or a full-bridge converter. AC / DC power converter 1022 converts alternating current to direct current, providing a supply voltage V1 to the switching circuit 101. In other words, the supply voltage V1 of output module 10 is the output voltage of AC / DC power converter 1022.

[0088] The switching circuit 101 is used to control the on / off state of the charging output and can be implemented by power devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs) or insulated-gate bipolar transistors (IGBTs).

[0089] When the output voltage / current is within the normal range, the LED cathode of optocoupler 1021 enters a balanced state between high and low levels. AC / DC power converter 1022 outputs DC voltage normally, and the charging control circuit outputs voltage normally.

[0090] When the rise in output voltage exceeds a first set value and the fall in output current exceeds a second set value within a set time, either the voltage control loop 20 or the current control loop 30 outputs a low level, forcibly pulling the LED cathode potential of the optocoupler 1021 down to a low level. A forward bias voltage is formed between the LED anode and cathode, causing the LED to conduct and emit light. The phototransistor conducts after being triggered by light, reducing its equivalent resistance. The output of the optocoupler 1021 is connected to the enable pin or feedback pin of the AC / DC power converter 1022. If connected to the enable pin, the AC / DC power converter 1022 pauses operation and stops outputting power after the phototransistor conducts. If connected to the feedback pin, the AC / DC power converter enters a current-limiting or shutdown mode after the phototransistor conducts. After the AC / DC power converter 1022 stops supplying power, the supply voltage V1 of the switching circuit 101 stops rising, and the output voltage no longer increases.

[0091] In some embodiments, the switching circuit 101 includes a switching transistor M1, a fifth capacitor C5, a tenth resistor R10, an eleventh resistor R11, and a sampling resistor Rs. The first terminal of the fifth capacitor C5 is connected to the first output terminal of the AC / DC power converter 1022, and the second terminal of the fifth capacitor is connected to the second output terminal of the AC / DC power converter 1022 and the first terminal of the sampling resistor Rs. The gate of the switching transistor M1 is connected to the control module 40, the first terminal of the switching transistor M1 is connected to the first terminal of the fifth capacitor C5, and the second terminal of the switching transistor M1 is connected to the positive output terminal of the switching circuit 101. The first terminal of the tenth resistor R10 is connected to the second terminal of the switching transistor M1, the second terminal of the tenth resistor R10 is connected to the first terminal of the eleventh resistor R11, and the second terminal of the eleventh resistor R11 is connected to the first terminal of the sampling resistor Rs. The second terminal of the sampling resistor Rs is connected to the negative output terminal of the switching circuit 101.

[0092] The first input pin of the control module 40 is connected to the second end of the sampling resistor Rs, and is used to acquire the output current of the output module 10. The second input pin of the control module 40 is connected to the second end of the tenth resistor R10, and the third input pin of the control module 40 is connected to the second end of the first resistor R1, and is used to acquire the output voltage of the output module 10.

[0093] In one embodiment, the control module 40 is further configured to adjust the reference voltage V-Ctrl at the second input terminal of the voltage control loop 20 to be greater than the output voltage, and to adjust the difference between the reference voltage V-Ctrl and the output voltage to a preset value. This configuration allows the voltage control loop 20 to be triggered by a slight increase in output voltage during hot-swapping, further accelerating the transmission of a signal to the voltage conversion unit 102 to stop outputting power (i.e., prevent the supply voltage V1 from continuing to rise).

[0094] The working process of the charging control circuit provided in the embodiment of this utility model is described below. Figure 6 This is a flowchart illustrating the working process of a charging control circuit provided in an embodiment of this utility model. For example... Figure 6 As shown, the operation of this charging control circuit includes:

[0095] S101. The output voltage and output current of the output module 10 are collected and controlled by the current control loop 30 to output constant current or by the voltage control loop 20 to output constant voltage.

[0096] Specifically, please refer to Figure 1 During normal charging, the control module 40 periodically (e.g., every 0.1ms) samples the output voltage and output current. The voltage control loop 20 compares the output voltage of the output module 10 with the reference voltage V-Ctrl provided by the control module 40, and adjusts the output voltage based on the comparison result to maintain it near the desired stable value. If the output voltage is higher than the reference voltage, the voltage control loop 20 decreases the output voltage; conversely, if the output voltage is lower than the reference voltage, the voltage control loop 20 increases the output voltage. In other words, the voltage control loop 20 controls the output module 10 to output a constant voltage. The current control loop 30 compares the output current of the output module 10 with the reference current I-Ctrl provided by the control module 40, and adjusts the output current based on the comparison result to maintain it near the desired stable value. If the output current is higher than the reference voltage, the current control loop 30 decreases the output current; conversely, if the output current is lower than the reference voltage, the current control loop 30 increases the output current. In other words, the current control loop 30 controls the output module 10 to output a constant current.

[0097] S102. If the change in output voltage and / or output current meets the preset conditions, the value at the second input terminal of the voltage control loop 20 is lowered and / or the value at the first input terminal of the current control loop 30 is raised to control the output module 10 to stop working.

[0098] Specifically, the preset conditions include that the rise in output voltage is greater than a first preset value within a set time period, and / or that the drop in output current is greater than a second preset value within a set time period.

[0099] It should be noted that detecting an output voltage rise greater than the first set value within a set time can also be understood as the time it takes for the output voltage rise to reach the first set value being within the set time. Detecting hot-plugging actions needs to balance rapid detection and interference resistance to achieve fast and accurate protection actions. Generally, the shorter the time from the hot-plugging action to its detection, the more timely the protection and the better the protection effect. Therefore, the set time should generally be less than 1 millisecond.

[0100] The first and second setting values ​​can be determined by actually measuring the changes in output voltage or current after hot-swapping, as well as the ripple of output voltage or current during normal operation, component differences, and reasonable tolerances. Generally, the first setting value is greater than the maximum ripple voltage during operation and less than one-tenth of the maximum output voltage. A smaller first setting value results in faster protection action, but increases the probability of false triggering; therefore, it should be set to a reasonable value. The second setting value is greater than the maximum ripple current during operation. For example, when charging at 48V output, the maximum output ripple voltage is 0.5V, including under normal interference conditions, so the first setting value can be 1V. Within 1 millisecond after hot-swapping (without protection), if the output voltage rises by more than 1V every 0.05 milliseconds (i.e., the 1V rise is within 0.05 milliseconds), considering component differences and fault tolerance, the setting time can be 0.1 milliseconds; if it rises by more than 1V within 0.1 seconds, the setting time can be 0.2 milliseconds, and so on.

[0101] In one embodiment, when the rise of the output voltage exceeds a first set value within a set time, the control module 40 determines that the output interface of the charging control circuit has a hot-plugging action. At this time, the control module 40 pulls down the value at the second input terminal of the voltage control loop 20, or the control module 40 pulls up the value at the first input terminal of the current control loop 30, or the control module 40 pulls down the value at the second input terminal of the voltage control loop 20 and pulls up the value at the first input terminal of the current control loop 30, so as to control the output module 10 to stop working.

[0102] In another embodiment, when the decrease in output current is greater than a second set value within a set time, the control module 40 determines that there is a hot-plugging action at the output interface of the charging control circuit. At this time, the control module 40 pulls down the value at the second input terminal of the voltage control loop 20, or the control module 40 pulls up the value at the first input terminal of the current control loop 30, or the control module 40 pulls down the value at the second input terminal of the voltage control loop 20 and pulls up the value at the first input terminal of the current control loop 30, so as to control the output module 10 to stop working.

[0103] In another embodiment, when the rise of the output voltage is greater than a first set value and the fall of the output current is greater than a second set value within a set time, the control module 40 determines that there is a hot-plugging action at the output interface of the charging control circuit. At this time, the control module 40 pulls down the value at the second input terminal of the voltage control loop 20, or the control module 40 pulls up the value at the first input terminal of the current control loop 30, or the control module 40 pulls down the value at the second input terminal of the voltage control loop 20 and pulls up the value at the first input terminal of the current control loop 30, so as to control the output module 10 to stop working.

[0104] In one embodiment, the control module 40 may provide a low-level voltage control signal to the second input terminal of the voltage control loop 20 to pull down the value at the second input terminal of the voltage control loop 20.

[0105] In another embodiment, the control module 40 can pull down the reference voltage V-Ctrl. For example, the reference voltage at the second input of the control voltage control loop 20 is 0, thereby pulling down the value at the second input of the voltage control loop 20.

[0106] In another embodiment, the control module 40 may provide a low-level voltage control signal to the second input of the voltage control loop 20 and pull down the reference voltage V-Ctrl to lower the value at the second input of the voltage control loop 20.

[0107] In one embodiment, the control module 40 may provide a high-level current control signal to the first input terminal of the current control loop 30 to pull up the value at the first input terminal of the current control loop 30.

[0108] In one embodiment, if the rise of the output voltage is greater than a first set value within a set time period, and / or the fall of the output current is greater than a second set value within a set time period, the reference current I-Ctrl of the current control loop 30 can be lowered.

[0109] The control method further includes: when the change in output voltage and / or output current does not meet the preset conditions, controlling the reference voltage V-Ctrl at the second input terminal of the voltage control loop 20 to be greater than the output voltage, and controlling the difference between the reference voltage V-Ctrl and the output voltage to be a preset value.

[0110] Specifically, please refer to Figure 5When the charging control circuit is in constant current mode and the changes in output voltage and / or output current do not meet the preset conditions, the reference voltage V-Ctrl of the voltage control loop 20 is dynamically adjusted so that the difference between the reference voltage V-Ctrl and the output voltage is a preset value. This allows the voltage control loop 20 to be triggered when the hot-plug is removed, as the output voltage increases slightly. This further helps to accelerate the sending of a signal to the voltage conversion unit 102 to stop the output of electrical energy (i.e., prevent the voltage V1 from continuing to rise).

[0111] The charging control circuit also includes the following steps: after the changes in output voltage and / or output current meet preset conditions, a preset time is delayed, and after the preset time delay, the values ​​at the second input terminal of the voltage control loop 20 and / or the first input terminal of the current control loop 30 are restored. This setting ensures a smooth recovery of the output voltage.

[0112] Specifically, a change in output voltage satisfying a preset condition indicates that the increase in output voltage is greater than a first set value. A change in output current satisfying a preset condition indicates that the decrease in output current is greater than a second set value.

[0113] In one embodiment, the value at the second input of the voltage control loop 20 is restored after a preset delay, i.e., the low-level voltage control signal V-Pulse is removed.

[0114] In one embodiment, the value at the second input terminal of the voltage control loop 20 is restored after a preset delay, i.e., the reference voltage V-Ctrl of the voltage control loop 20 is restored.

[0115] In one embodiment, after a preset delay, the value at the second input terminal of the voltage control loop 20 is restored, that is, the low-level voltage control signal V-Pulse is removed and the reference voltage V-Ctrl of the voltage control loop 20 is restored.

[0116] In one embodiment, the value at the first input of the current control loop 30 is restored after a preset delay, i.e., the high-level current control signal I-Pulse is removed.

[0117] The charging control circuit also includes the following steps: after the changes in output voltage and / or output current meet preset conditions, a preset time is delayed; after the preset time delay, the values ​​at the second input terminal of the voltage control loop 20 and / or the first input terminal of the current control loop 30 are restored, and the reference current I-Ctrl of the current control loop 30 is also restored. This setting ensures a smooth recovery of the output voltage.

[0118] The conditions for the change in output voltage and the change in output current to meet the preset conditions are the same as those mentioned above, and will not be repeated here.

[0119] In one embodiment, after a preset delay, the value at the second input terminal of the voltage control loop 20 is restored, and the reference current I-Ctrl of the current control loop 30 is also restored (i.e., the low-level voltage control signal V-Pulse is removed, and the reference current I-Ctrl of the current control loop 30 is restored).

[0120] In one embodiment, after a preset delay, the value at the second input terminal of the voltage control loop 20 is restored, and the reference current I-Ctrl of the current control loop 30 is also restored (i.e., the reference voltage V-Ctrl of the voltage control loop 20 and the reference current I-Ctrl of the current control loop 30 are restored).

[0121] In one embodiment, after a preset delay, the value at the second input terminal of the voltage control loop 20 is restored, and the reference current I-Ctrl of the current control loop 30 is also restored (i.e., the low-level voltage control signal V-Pulse is removed, and the reference voltage V-Ctrl of the voltage control loop 20 and the reference current I-Ctrl of the current control loop 30 are restored).

[0122] In one embodiment, after a preset delay, the value at the first input terminal of the current control loop 30 is restored, and the reference current I-Ctrl of the current control loop 30 is also restored (i.e., the high-level current control signal I-Pulse is removed, and the reference current I-Ctrl of the current control loop 30 is also restored).

[0123] In one embodiment, after the change in output voltage and / or output current meets a preset condition, a preset time is applied. After the preset time delay, the current control signal I-Pulse and the voltage control signal V-Pulse are sequentially removed, and the reference voltage V-Ctrl and the reference current I-Ctrl are synchronously restored sequentially, so that the charging control circuit returns to normal operation. This sequence ensures that the voltage control loop remains active after protection, thereby better guaranteeing a smooth recovery of the output voltage.

[0124] To verify the actual effect of this utility model embodiment, the following experiment was conducted:

[0125] Experimental conditions: Set the reference current of the current control loop to approximately 4A in constant current mode, and set the reference voltage of the voltage control loop to approximately 70V in constant voltage mode. Ensure that the output voltage stabilizes at approximately 70V after hot-swapping. Connect a 48V load for testing. Connect an oscilloscope probe to the output electrolytic capacitor to evaluate the output voltage change after hot-swapping.

[0126] Figure 7This is a waveform measurement diagram of the output voltage during the hot-plugging and unplugging process of the charging control circuit in related technologies. (Reference) Figure 7 The left segment shows the output voltage under stable constant current mode, approximately 48V, while the right segment shows the output voltage under constant voltage mode, approximately 70V. A sharp voltage rise in the middle indicates a disconnection action occurred, producing a large spike (approximately 18V higher than the constant voltage level), and it took a considerable amount of time to return to the constant voltage state (over 2 seconds).

[0127] Figure 8 This is a measurement diagram of the output voltage waveform during the hot-plugging and unplugging process of the charging control circuit provided in this embodiment of the utility model. (Reference) Figure 8 The left segment shows the output voltage, approximately 48V, operating stably in constant current mode, while the right segment shows the output voltage, approximately 70V, operating in constant voltage mode. A brief drop occurs during the voltage rise, which indicates the charging control method provided in this embodiment is functioning correctly. The waveform when the output voltage continues to rise to near the 70V constant voltage mode is smooth, without any spikes. Furthermore, the time from hot-plugging to returning to a stable constant voltage state is minimal (approximately 0.1 seconds). These comparative test results verify the effectiveness of this embodiment.

[0128] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A charging control circuit, characterized in that, include: Output module, voltage control loop, current control loop, and control module; The control module is coupled to the output module and configured to receive the output current and output voltage of the output module; The voltage control loop has a first input terminal, a second input terminal, and an output terminal. Its first input terminal is used to receive the power supply voltage of the output module, and its second input terminal is coupled to the first output pin of the control module. The control module is configured to provide a reference voltage to the second input terminal of the voltage control loop. The current control loop has a first input terminal, a second input terminal, and an output terminal. Its first input terminal is coupled to the second output pin of the control module, and its second input terminal is coupled to the third output pin of the control module. The control module is configured to provide a value representing the output current at the first input terminal of the current control loop and to provide a reference current at the second input terminal of the current control loop. The control module is used to pull down the value at the second input terminal of the voltage control loop and / or pull up the value at the first input terminal of the current control loop.

2. The charging control circuit according to claim 1, characterized in that, The voltage control loop includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, and a second capacitor; The first end of the first resistor is used to receive the power supply voltage of the output module, and the second end of the first resistor is connected to the first end of the second resistor and the first end of the third resistor; The second end of the second resistor is connected to the first input terminal of the first operational amplifier, and the second end of the third resistor is grounded; The first end of the fourth resistor is connected to the first output pin of the control module, the second end of the fourth resistor is connected to the second input terminal of the first operational amplifier and the first end of the first capacitor, and the second end of the first capacitor is grounded. The first end of the second capacitor is connected to the first input terminal of the first operational amplifier, the second end of the second capacitor is connected to the first end of the fifth resistor, and the second end of the fifth resistor is connected to the output terminal of the first operational amplifier.

3. The charging control circuit according to claim 1, characterized in that, The current control loop includes a second operational amplifier, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, and a fourth capacitor; The first end of the sixth resistor is connected to the first input terminal of the second operational amplifier, the second end of the sixth resistor is connected to the first end of the seventh resistor, and the second end of the seventh resistor is connected to the second output pin of the control module. The first end of the eighth resistor is connected to the third output pin of the control module, the second end of the eighth resistor is connected to the second input terminal of the second operational amplifier and the first end of the third capacitor, and the second end of the third capacitor is grounded. The first terminal of the fourth capacitor is connected to the first input terminal of the second operational amplifier, the second terminal of the fourth capacitor is connected to the first terminal of the ninth resistor, and the second terminal of the ninth resistor is connected to the output terminal of the second operational amplifier.

4. The charging control circuit according to claim 1, characterized in that, The control module also has a fourth output pin, which is coupled to the second input terminal of the voltage control loop. The control module is used to provide a low-level voltage control signal to the second input terminal of the voltage control loop and / or pull down the reference voltage.

5. The charging control circuit according to claim 1 or 4, characterized in that, The control module also has a fifth output pin, which is coupled to the first input terminal of the current control loop. The control module is used to provide a high-level current control signal to the first input terminal of the current control loop.

6. The charging control circuit according to claim 1, characterized in that, The control module is also used to pull down the reference current.

7. The charging control circuit according to claim 1, characterized in that, The output module includes a switching circuit and a voltage conversion unit; The voltage conversion unit is coupled to the output terminals of the voltage control loop and the current control loop, and the voltage conversion unit is also coupled to the switching circuit.

8. The charging control circuit according to claim 7, characterized in that, The voltage conversion unit includes an optocoupler and an AC / DC power converter; The input terminal of the optocoupler is connected to the output terminals of the voltage control loop and the current control loop. The output terminal of the optocoupler is connected to the enable pin or feedback pin of the AC / DC power converter. The output terminal of the AC / DC power converter is connected to the switching circuit to provide the power supply voltage to the switching circuit.

9. The charging control circuit according to claim 8, characterized in that, The switching circuit includes a switching transistor, a fifth capacitor, a tenth resistor, an eleventh resistor, and a sampling resistor; The first terminal of the fifth capacitor is connected to the first output terminal of the AC / DC power converter, and the second terminal of the fifth capacitor is connected to the second output terminal of the AC / DC power converter and the first terminal of the sampling resistor. The gate of the switching transistor is connected to the control module, the first terminal of the switching transistor is connected to the first terminal of the fifth capacitor, and the second terminal of the switching transistor is connected to the positive output terminal of the switching circuit. The first end of the tenth resistor is connected to the second terminal of the switching transistor, the second end of the tenth resistor is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the first end of the sampling resistor, and the second end of the sampling resistor is connected to the negative output terminal of the switching circuit.

10. The charging control circuit according to claim 1, characterized in that, The control module is also used to adjust the reference voltage at the second input terminal of the voltage control loop to be greater than the output voltage, and to adjust the difference between the reference voltage and the output voltage to a preset value.

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