A control circuit for preventing hot plugging during high-voltage lithium battery charging

Abstract

A control circuit for preventing hot plugging during high-voltage lithium battery charging, comprising a charge pump module for converting the power supply voltage VDD into a high-voltage power supply V1, a clamping module for limiting the high-voltage power supply V1 to a fixed voltage. The clamping module includes a first clamping unit and a second clamping unit connected in series between the high-voltage power supply V1 and the ground terminal in sequence, a control switch MLC1, a high-voltage transistor MHV1, an LDO module for converting the power supply V2 voltage into the normal charging voltage VBAT of the battery, and a battery full detection circuit for detecting the charging state of the battery. When the battery is in the charging state, the high-voltage transistor MHV1 is turned on, and V2 = VIN; when the battery is in the full state, the battery full detection circuit outputs a high-level signal to the control switch MLC1, the control switch MLC1 is turned on, and the control switch MLC1 shorts the second clamping unit to reduce the voltage of the high-voltage power supply V1 to protect the LDO module.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuit design, and relates to a control circuit for preventing hot plugging during high-voltage lithium battery charging. Background Art

[0002] In order to avoid damaging the chip when performing hot plugging operations on the lithium battery when it is close to full charge, protection actions need to be taken during hot plugging operations for high-voltage lithium battery charging. That is, the control circuit for preventing hot plugging during high-voltage lithium battery charging is becoming more and more widely used.

[0003] Please refer to Figure 1 , Figure 1 shown in the schematic diagram of the control circuit for preventing hot plugging during high-voltage lithium battery charging in the prior art. As Figure 1 shown, the circuit generally can include a charge pump circuit, a clamping circuit, a high-voltage transistor MHV1, an LDO module, etc.

[0004] The charge pump circuit can include an oscillator module, capacitor C1, capacitor C2, charge pump switch transistors M1, M2, M3, and M4; the oscillator module generates a CLK signal and a CLKN signal, where the CLKN signal is the inverted signal of the CLK signal; when the CLK signal is at a high level, the CLKN signal is at a low level; charge pump switch transistor M1 is turned on, and charge pump switch transistor M2 is turned off; charge pump switch transistor M3 is turned off, and charge pump switch transistor M4 is turned on, and the voltage of 2*VDD is transmitted to V1 through charge pump switch transistor M4; when the CLK signal is at a low level, the CLKN signal is at a high level; charge pump switch transistor M2 is turned on, and charge pump switch transistor M1 is turned off; charge pump switch transistor M4 is turned off, and charge pump switch transistor M3 is turned on, and the voltage of 2*VDD is transmitted to V1 through charge pump switch transistor M3; in this way, V1 can maintain a voltage of 2 times VDD.

[0005] Clamping circuit: Since the voltage of V1 = 2*VDD may exceed the drain G-terminal withstand voltage value of the high-voltage device MHV1, a clamping circuit is required. This clamping circuit can be generated by connecting several Zener diodes in series as shown in Figure 1 ; it can also be generated by connecting the gate and drain terminals of a transistor and connecting several in series as shown in Figure 2 ; or it can be generated by connecting a Zener diode and the gate and drain terminals of a common MOS transistor in series.

[0006] High-voltage transistor MHV1: When VIN is at a low voltage, the high-voltage transistor is turned on, and V2 = VIN; when VIN is at a relatively high voltage, this device acts as a voltage-blocking tube to protect the low-voltage circuit below.

[0007] LDO module: It converts the voltage V2 into a normal charging voltage VBAT to control the normal charging of the battery. The LDO module is a circuit composed of low-voltage devices.

[0008] The above-mentioned existing technologies have the following disadvantages:

[0009] During normal operation, VIN is powered by a relatively low voltage VA. To ensure that a large amount of power consumption does not occur during the power supply process of the high-voltage transistor, generally, the voltage at the G terminal (drain) of the high-voltage transistor MHV1 is higher than the VIN voltage, so that it operates in the deep linear region to ensure its full conduction. However, when the charging is nearly complete, there will be a hot plugging operation at the VIN power supply terminal, and this operation will cause a spike pulse with a relatively high voltage to be generated instantaneously at the VIN voltage.

[0010] Since the high-voltage transistor MHV1 is operating in the deep linear region at this time, the V2 voltage will also generate a spike pulse accordingly (as Figure 3 shown); its highest voltage may reach the voltage value of V1 - VGS. Since the LDO module is a circuit composed of low-voltage devices, the pulse voltage with the highest voltage reaching V1 - VGS will still cause damage to the low-voltage devices inside the LDO module. Summary of the Invention

[0011] To solve the above technical problems, the present invention proposes a control circuit for preventing hot plugging in high-voltage lithium battery charging, which can solve the problem of abnormal damage to the chip during hot plugging operation when the high-voltage lithium battery is charged and nearly full.

[0012] To achieve the above object, the technical solution of the present invention is as follows:

[0013] A control circuit for preventing hot plugging in high-voltage lithium battery charging, which includes:

[0014] A charge pump module for converting the power supply voltage VDD into a high-voltage power supply V1;

[0015] A clamping module, which includes a first clamping unit and a second clamping unit connected in series between the high-voltage power supply V1 and the ground terminal, for limiting the high-voltage power supply V1 to a fixed voltage;

[0016] A control switch MLC1, whose source is connected to the connection point of the first clamping unit and the second clamping unit, and whose drain is grounded;

[0017] A high-voltage transistor MHV1, whose source is connected to the power supply VIN, whose drain is connected to the power supply V2, and whose gate is connected to the high-voltage power supply V1;

[0018] An LDO module for converting the voltage of the power supply V2 into a charging voltage VBAT to control the normal charging of the battery;

[0019] The battery full detection circuit is used to detect the charging state of the battery; wherein,

[0020] When the battery is in the charging state, the high-voltage transistor MHV1 is turned on, and V2 = VIN; when the battery is full, the battery full detection circuit outputs a high-level signal to the control switch MLC1, the control switch MLC1 is turned on, and the control switch MLC1 shorts the second clamping unit to reduce the voltage of the high-voltage power supply V1 to protect the LDO module.

[0021] Further, the battery full detection module includes a low-voltage transistor MLV1, a first comparator, a resistor R3, and a low-voltage transistor MLV2 that mirrors the low-voltage transistor MLV1, and is used to mirror the current of the low-voltage transistor MLV1, that is, the current passing through the low-voltage transistor MLV2 is IMV2 = k * IMV1; the gate of the low-voltage transistor MLV2 is connected to the gate of the low-voltage transistor MLV1, the source of the low-voltage transistor MLV2 is connected to the power supply V2, the resistor R3 is connected between the drain of the low-voltage transistor MLV2 and the positive input terminal and the ground terminal of the comparator, and the negative input terminal of the comparator is connected to the reference voltage VREF1;

[0022] When IMV2 * R3 < VREF1, the battery reaches the first voltage threshold, the comparator outputs a high-level signal to the control switch MLC1, the control switch MLC1 is turned on, and the control switch MLC1 shorts the second clamping unit to reduce the voltage of the high-voltage power supply V1.

[0023] Further, the charge pump module includes an oscillator module, a capacitor C1, a capacitor C2, a charge pump switch tube M1, a charge pump switch tube M2, a charge pump switch tube M3, and a charge pump switch tube M4; the oscillator module generates a CLK signal and a CLKN signal, wherein the CLKN signal is the inverted signal of the CLK signal; when the CLK signal is at a high level, the CLKN signal is at a low level; the charge pump switch tube M1 is turned on, and the charge pump switch tube M2 is turned off; the charge pump switch tube M3 is turned off, and the charge pump switch tube M4 is turned on, and the voltage of 2 * VDD is transmitted to V1 through the charge pump switch tube M4; when the CLK signal is at a low level, the CLKN signal is at a high level; the charge pump switch tube M2 is turned on, and the charge pump switch tube M1 is turned off; the charge pump switch tube M4 is turned off, and the charge pump switch tube M3 is turned on, and the voltage of 2 * VDD is transmitted to V1 through the charge pump switch tube M3; that is, the voltage V1 maintains twice the VDD voltage.

[0024] Further, the first clamping unit is a Zener diode, and the second clamping unit is a MOS transistor in series; or, the second clamping unit is a Zener diode, and the first clamping unit is a MOS transistor in series.

[0025] Further, the first clamping unit and / or the second clamping unit are N transistors connected in series, and the gates and drains of the N transistors are connected.

[0026] Further, the control circuit for preventing hot plugging during high-voltage lithium battery charging is characterized by further comprising a control switch MLC2 and a VIN overvoltage detection module: when the power supply VIN is higher than the second voltage threshold, the overvoltage detection circuit generates an overvoltage signal to trigger the control switch MLC2, so that the voltage of the high-voltage power supply V1 is shorted to the ground terminal to turn off the high-voltage transistor MHV1.

[0027] Further, the VIN overvoltage detection module includes a low-voltage transistor MLV2, a second comparator, a resistor R4 and a resistor R5. The negative input terminal of the comparator is connected to a reference voltage VREF1; the resistors R4 and R5 are connected in series between the power supply VIN and the ground terminal, and the positive input terminal of the comparator is connected to the connection point of the resistors R4 and R5.

[0028] As can be seen from the above technical solutions, the control circuit for preventing hot plugging during high-voltage lithium battery charging in the present invention, by adding a control circuit for internal high-voltage charging devices, avoids the damage to low-voltage devices inside the chip caused by overvoltage pulses during hot plugging by controlling the value of the clamping voltage at the G terminal of the high-voltage transistor in the prior art. It not only improves the chip lifespan but also achieves the effect of reducing the chip cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It shows a schematic diagram of a control circuit for preventing hot plugging during high-voltage lithium battery charging in the prior art

[0030] Figure 2 It is a schematic diagram of the peak voltage of VIN during hot plugging of the control circuit shown in FIG. 1

[0031] Figure 3 It shows a schematic diagram of a preferred embodiment of the control circuit for preventing hot plugging during high-voltage lithium battery charging in the present invention

[0032] Figure 4 It shows a schematic diagram of a clamping circuit in the control circuit for preventing hot plugging during high-voltage lithium battery charging in an embodiment of the present invention

[0033] Figure 5 For the present invention Figure 4 It is a schematic diagram of the peak voltage of VIN during hot plugging of the control circuit shown

[0034] Figure 6 It shows a schematic diagram of another control circuit for preventing hot plugging during high-voltage lithium battery charging in an embodiment of the present invention

[0035] Figure 7 For the present invention Figure 6 Schematic diagram of the peak voltage of VIN during hot plugging in the embodiment shown Specific embodiments

[0036] The following combines the attached Figures 3 - 7 to further elaborate on the specific embodiments of the present invention in detail.

[0037] It should be noted that the biggest difference between the present invention and the prior art is that in the control circuit for preventing hot plugging during high - voltage lithium - battery charging of the present invention, a battery full detection module is added. When the battery is approaching full charge, the battery full detection module reduces the voltage V1 of the charging power supply by controlling the switch MLC1; further, a VIN over - voltage detection module can also be added. When the VIN voltage is higher than a certain voltage, the over - voltage detection circuit generates an over - voltage signal, and by controlling the switch MLC2, the voltage of V1 is short - circuited to the ground terminal GND.

[0038] Please refer to Figure 3 , Figure 3 The schematic diagram of a preferred embodiment of the control circuit for preventing hot plugging during high - voltage lithium - battery charging of the present invention is shown. As Figure 3 shown, the control circuit for preventing hot plugging during high - voltage lithium - battery charging includes a charge pump module for converting the power supply voltage VDD into a high - voltage power supply V1, a clamping module, a control switch MLC1, a high - voltage transistor MHV1, an LDO module, and a battery full detection circuit.

[0039] In the embodiments of the present invention, the charge pump modules in the prior art can all be used. For example, as Figure 3 shown, the charge pump module can include an oscillator module, a capacitor C1, a capacitor C2, a charge pump switch tube M1, a charge pump switch tube M2, a charge pump switch tube M3, and a charge pump switch tube M4; the oscillator module generates a CLK signal and a CLKN signal, where the CLKN signal is the inverted signal of the CLK signal; when the CLK signal is at a high level, the CLKN signal is at a low level; the charge pump switch tube M1 is turned on, and the charge pump switch tube M2 is turned off; the charge pump switch tube M3 is turned off, and the charge pump switch tube M4 is turned on, and the voltage of 2*VDD is transmitted to V1 through the charge pump switch tube M4; when the CLK signal is at a low level, the CLKN signal is at a high level; the charge pump switch tube M2 is turned on, and the charge pump switch tube M1 is turned off; the charge pump switch tube M4 is turned off, and the charge pump switch tube M3 is turned on, and the voltage of 2*VDD is transmitted to V1 through the charge pump switch tube M3; in this way, V1 can maintain a voltage of 2 times VDD.

[0040] The clamping module is used to limit the high-voltage power supply V1 to a fixed voltage. It may include a first clamping unit and a second clamping unit connected in series between the high-voltage power supply V1 and the ground terminal in sequence. The source of the control switch MLC1 is connected to the connection point of the first clamping unit and the second clamping unit, and the drain is grounded.

[0041] It should be noted that the first clamping unit and the second clamping unit may be the same or different. Please refer to Figure 4 , Figure 4 The figure shows a schematic diagram of the clamping circuit in the control circuit for preventing hot plugging during high-voltage lithium battery charging in an embodiment of the present invention. The first clamping unit and / or the second clamping unit may be a Zener diode. Additionally, this clamping module may also be, for example, Figure 4 as shown in, connecting the gate and source terminals of a transistor, and connecting several in series to generate; or connecting and serially generating by connecting a Zener diode and the gate and source terminals of a common MOS transistor.

[0042] The source of the control switch MLC1 is connected to the connection point of the first clamping unit and the second clamping unit, and the drain is grounded. For the high-voltage transistor MHV1, its source is connected to the power supply VIN, the drain is connected to the power supply V2, and the gate is connected to the high-voltage power supply V1; the LDO module converts the voltage of the power supply V2 into the charging voltage VBAT to control the normal charging of the battery; the battery full detection circuit is used to detect the charging state of the battery.

[0043] Among them, when the battery is in the charging state and the power supply VIN is at a low voltage, the high-voltage transistor MHV1 conducts, and V2 = VIN; when the battery is full, the battery full detection circuit outputs a high-level signal to the control switch MLC1, the control switch MLC1 is turned on, and the control switch MLC1 shorts the second clamping unit to reduce the voltage of the high-voltage power supply V1 to protect the LDO module.

[0044] Specifically, the battery full detection module includes a low-voltage transistor MLV1, a comparator, a resistor R3, and a low-voltage transistor MLV2 that mirrors the low-voltage transistor MLV1, which is used to mirror the current of the low-voltage transistor MLV1, that is, the current passing through the low-voltage transistor MLV2 is IMV2 = k * IMV1; the low-voltage transistor MLV2 is connected to the gate of the low-voltage transistor MLV1, the source of the low-voltage transistor MLV2 is connected to the power supply V2, the resistor R3 is connected between the drain of the low-voltage transistor MLV2 and the positive input terminal of the comparator and the ground terminal, and the negative input terminal of the comparator is connected to the reference voltage VREF1.

[0045] When IMV2*R3 < VREF1, the battery reaches the first voltage threshold, the comparator outputs a high-level signal to the control switch MLC1, the control switch MLC1 is turned on, and the control switch MLC1 shorts the second clamping unit to reduce the voltage of the high-voltage power supply V1.

[0046] Please refer to Figure 5 , Figure 5 for the present invention Figure 4 shown in the schematic diagram of the spike voltage of VIN during hot plugging of the control circuit. In the embodiment of the present invention, through the newly added battery full detection circuit, during normal charging applications, in order to ensure that a large amount of power consumption does not occur in the high-voltage transistor MHV1 during power supply, generally, the voltage at the G terminal (gate) of the high-voltage transistor MHV1 is higher than the VIN voltage, so that it operates in the deep linear region to ensure its full conduction; however, when charging is nearly complete, the voltage V1 at the G terminal of its high-voltage transistor MHV1 is greatly reduced through the short-circuit clamping unit.

[0047] Since the voltage V1 is greatly reduced at this time, the high-voltage transistor MHV1 can operate in the linear region or the saturation region. Although a spike pulse will also be generated in the V2 voltage, and its highest voltage may reach the voltage value of V1 - VGS, since the voltage V1 has been greatly reduced. Therefore, this embodiment of the present invention can ensure the withstand voltage requirements of the low-voltage devices in the LDO module and will not cause damage to the chip during hot plugging.

[0048] Please refer to Figure 6 , Figure 6 shown in the schematic diagram of another control circuit for preventing hot plugging during high-voltage lithium battery charging in the embodiment of the present invention. As Figure 6 shown, in this embodiment, the control circuit for preventing hot plugging during high-voltage lithium battery charging, in addition to including a charge pump module, a clamping module, a control switch MLC1, a high-voltage transistor MHV1, an LDO module, and a battery full detection circuit for converting the power supply voltage VDD into a high-voltage power supply V1, also includes a control switch MLC2 and a VIN overvoltage detection module; when the power supply VIN is higher than the second voltage threshold, the overvoltage detection circuit generates an overvoltage signal to trigger the control switch MLC2, so that the voltage of the high-voltage power supply V1 is shorted to the ground terminal to turn off the high-voltage transistor MHV1.

[0049] Similarly, the battery full detection circuit is used to detect the charging state of the battery; wherein, when the battery is in the charging state, the high-voltage transistor MHV1 is turned on, V2 = VIN; the battery full detection circuit outputs a high-level signal to the control switch MLC1, the control switch MLC1 is turned on, and the control switch MLC1 shorts the second clamping unit to reduce the voltage of the high-voltage power supply V1 to protect the LDO module.

[0050] Specifically, in an embodiment of the present invention, the VIN overvoltage detection module includes a low-voltage transistor MLV2, a second comparator, a resistor R4, and a resistor R5. The negative input terminal of the comparator is connected to a reference voltage VREF1; the resistors R4 and R5 are connected in series between the power supply VIN and the ground terminal, and the positive input terminal of the comparator is connected to the connection point of the resistors R4 and R5.

[0051] Please refer to Figure 7 , Figure 7 for the present invention Figure 6 which is a schematic diagram of the spike voltage of VIN during hot plugging in the illustrated embodiment. As Figure 7 shown, during normal charging applications, in order to ensure that a large amount of power consumption does not occur in the high-voltage transistor during power supply, generally, the voltage of the G terminal (gate) of the high-voltage transistor MHV1 is higher than the VIN voltage, so that it operates in the deep linear region to ensure its full conduction; however, when charging is nearly complete, the voltage V1 of its G terminal (gate) is greatly reduced by means of the second clamping unit.

[0052] That is to say, if there is a hot plugging action at the VIN terminal power supply at this time, this action will cause a spike pulse with a relatively high voltage to be instantaneously generated in the VIN voltage. Since the voltage V1 is greatly reduced at this time, the high-voltage transistor MHV1 can operate in the linear region or the saturation region. Although a spike pulse will also be generated in the V2 voltage, its highest voltage may reach the voltage value of V1 - VGS, but since the voltage V1 has been greatly reduced. This ensures the withstand voltage requirements of the low-voltage devices in the LDO module and will not cause damage to the chip during hot plugging.

[0053] In addition, in order to further protect the chip from the influence of the overcharge pulse voltage of the power supply VIN voltage, a VIN overvoltage detection module is added in this embodiment. When the VIN overvoltage detection module is higher than a certain voltage during hot plugging, the high-voltage transistor MHV1 can be directly turned off through the MLC2 transistor to further protect the internal circuit (LDO module).

[0054] The above are only the preferred embodiments of the present invention, and the embodiments are not intended to limit the patent protection scope of the present invention. Therefore, any equivalent structural changes made by using the description and drawings of the present invention should, by the same token, be included in the protection scope of the present invention.

Claims

1. A control circuit for preventing hot plugging during high-voltage lithium battery charging, characterized in that, Comprising: A charge pump module for converting the power supply voltage VDD into a high-voltage power supply V1; A clamping module including a first clamping unit and a second clamping unit connected in series between the high-voltage power supply V1 and the ground terminal for limiting the high-voltage power supply V1 to a fixed voltage; A control switch MLC1 with its source connected to the connection point of the first clamping unit and the second clamping unit and its drain grounded; A high-voltage transistor MHV1 with its source connected to the power supply VIN, its drain connected to the power supply V2, and its gate connected to the high-voltage power supply V1; An LDO module for converting the voltage of the power supply V2 into a charging voltage VBAT to control the normal charging of the battery; A battery full detection circuit for detecting the charging state of the battery; the battery full detection circuit includes a low-voltage transistor MLV1, a comparator, a resistor R3, and a low-voltage transistor MLV2 mirroring the low-voltage transistor MLV1, where the low-voltage transistor MLV2 is used to mirror the current of its low-voltage transistor MLV1, i.e., the current passing through the low-voltage transistor MLV2 is IMV2 = k * IMV1; the low-voltage transistor MLV2 is connected to the gate of the low-voltage transistor MLV1, the source of the low-voltage transistor MLV2 is connected to the power supply V2, the resistor R3 is connected between the drain of the low-voltage transistor MLV2 and the positive input terminal and the ground terminal of the comparator, and the negative input terminal of the comparator is connected to a reference voltage VREF1; wherein, When the battery is in the charging state, the high-voltage transistor MHV1 is turned on and V2 = VIN; when the battery is full, the battery full detection circuit outputs a high-level signal to the control switch MLC1, the control switch MLC1 is turned on, and the control switch MLC1 shorts the second clamping unit to reduce the voltage of the high-voltage power supply V1 to protect the LDO module.

2. The control circuit for preventing hot plugging during high-voltage lithium battery charging according to claim 1, characterized in that, The battery full detection module includes a low-voltage transistor MLV1, a first comparator, a resistor R3, and a low-voltage transistor MLV2 mirroring the low-voltage transistor MLV1 for mirroring the current of its low-voltage transistor MLV1, i.e., the current passing through the low-voltage transistor MLV2 is IMV2 = k * IMV1; the low-voltage transistor MLV2 is connected to the gate of the low-voltage transistor MLV1, the source of the low-voltage transistor MLV2 is connected to the power supply V2, the resistor R3 is connected between the drain of the low-voltage transistor MLV2 and the positive input terminal and the ground terminal of the comparator, and the negative input terminal of the comparator is connected to a reference voltage VREF1; When IMV2 * R3 < VREF1, i.e., when the battery full detection circuit detects that the charging current is less than a certain threshold, the battery reaches a first voltage threshold, the comparator outputs a high-level signal to the control switch MLC1, the control switch MLC1 is turned on, and the control switch MLC1 shorts the second clamping unit to reduce the voltage of the high-voltage power supply V1.

3. The control circuit for preventing hot plugging during high-voltage lithium battery charging according to claim 1, characterized in that, The charge pump module includes an oscillator module, capacitor C1, capacitor C2, charge pump switching transistor M1, charge pump switching transistor M2, charge pump switching transistor M3, and charge pump switching transistor M4; the oscillator module generates a CLK signal and a CLKN signal, where the CLKN signal is the inverted signal of the CLK signal; when the CLK signal is at a high level, the CLKN signal is at a low level; the charge pump switching transistor M1 is turned on, and the charge pump switching transistor M2 is turned off; the charge pump switching transistor M3 is turned off, and the charge pump switching transistor M4 is turned on, and the voltage of 2*VDD is transmitted to V1 through the charge pump switching transistor M4; when the CLK signal is at a low level, the CLKN signal is at a high level; the charge pump switching transistor M2 is turned on, and the charge pump switching transistor M1 is turned off; the charge pump switching transistor M4 is turned off, and the charge pump switching transistor M3 is turned on, and the voltage of 2*VDD is transmitted to V1 through the charge pump switching transistor M3; that is, the voltage V1 maintains a voltage twice that of VDD.

4. The control circuit for preventing hot plugging during high-voltage lithium battery charging according to claim 3, wherein The first clamping unit is a Zener diode, and the second clamping unit is a series connection of MOS transistors; alternatively, the second clamping unit is a Zener diode, and the first clamping unit is a series connection of MOS transistors; or both the first clamping unit and the second clamping unit are Zener diodes.

5. The control circuit for preventing hot plugging during high-voltage lithium battery charging according to claim 1, wherein, The first clamping unit and / or the second clamping unit is / are N transistors connected in series, and the gates and drains of the N transistors are connected.

6. The control circuit for preventing hot plugging during high-voltage lithium battery charging according to claim 1, wherein It further includes a control switch MLC2 and a VIN overvoltage detection module: when the power supply VIN is higher than the second voltage threshold, the overvoltage detection module generates an overvoltage signal to trigger the control switch MLC2, so that the voltage of the high-voltage power supply V1 is short-circuited to the ground terminal to turn off the high-voltage transistor MHV1.

7. The control circuit for preventing hot plugging during high-voltage lithium battery charging according to claim 6, wherein The VIN overvoltage detection module includes a low-voltage transistor MLV2, a second comparator, resistor R4, and resistor R5. The negative input terminal of the comparator is connected to the reference voltage VREF1; the resistor R4 and the resistor R5 are connected in series between the power supply VIN and the ground terminal, and the positive input terminal of the comparator is connected to the connection point of the resistor R4 and the resistor R5.

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