Charging drive circuit and battery system

Abstract

Embodiments of the present application provide a charging drive circuit and battery system. The charging drive circuit is integrated into a battery protection chip and includes: a battery detection module configured to output a charging overvoltage protection control signal, wherein the high-level voltage of the charging overvoltage protection control signal is a first power supply voltage; a level conversion module that receives the charging overvoltage protection control signal and performs level conversion on the charging overvoltage protection control signal to obtain a charging overvoltage protection drive signal, wherein the low-level voltage of the charging overvoltage protection drive signal is a second power supply voltage, which is higher than the first power supply voltage; and a charging overvoltage protection pin that outputs the charging overvoltage protection drive signal to the control terminal of a charging switch to control the conduction and cutoff of the charging switch. This application eliminates the need for a pull-up resistor connected in series between the battery protection chip and the charging control port, thereby reducing system power consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of battery protection, and in particular to a charging drive circuit and a battery system. Background Art

[0002] For the battery charge and discharge protection circuit, during normal charging, the charging switch is turned on or off by the voltage level output by the battery protection chip's charging pin, thereby controlling the state of the battery charging path. The charging pin is generally configured as an open-drain output.

[0003] When the battery is charging normally, the battery protection chip outputs a low level by pulling down the charge pin voltage, turning on the charging switch tube coupled to the charge pin. When the battery is overcharged, battery charging needs to be prohibited, and the charge pin outputs a high level to the charge switch tube, turning off the charge switch tube. However, because the charge pin is generally configured as an open-drain output, the charge pin in the battery protection chip does not have the ability to actively pull up the voltage level. Therefore, in order to ensure that the voltage of the charge pin can be pulled up to the power supply output terminal potential when charging is prohibited, so that the charge switch tube is in the off state, two conditions must be met simultaneously: Condition 1: The battery protection chip cannot pull down the voltage of the charge output pin. Condition 2: The battery protection circuit needs to connect a pull-up resistor in series between the power supply output terminal and the charge pin.

[0004] This leads to some problems. When the battery is charging or discharging normally, the potential of the charge pin needs to be pulled low to turn on the charge switch. However, in order to pull the potential of the charge pin low, a current must continue to flow through the pull-up resistor. This current will shorten the effective standby time of the battery. Summary of the Invention

[0005] In order to obtain a high-level output from the charging pin in the prior art, a pull-up resistor needs to be added to the battery charge and discharge protection circuit to cut off the charging switch tube, thereby increasing circuit power consumption.

[0006] In a first aspect, an embodiment of the present application provides a charging drive circuit and a battery system, which are integrated into a battery protection chip, and include: a battery detection module, configured to output a charging overvoltage protection control signal, wherein the high-level voltage of the charging overvoltage protection control signal is a first power supply voltage; a level conversion module, which receives the charging overvoltage protection control signal and performs level conversion on the charging overvoltage protection control signal to obtain a charging overvoltage protection drive signal, wherein the high-level voltage of the charging overvoltage protection drive signal is a second power supply voltage, and the second power supply voltage is higher than the first power supply voltage; and a charging overvoltage protection pin, which outputs the charging overvoltage protection drive signal to the control end of the charging switch to control the conduction and cutoff of the charging switch.

[0007] In one possible implementation, the low-level voltage of the charging overvoltage protection control signal is a third power supply voltage, the low-level voltage of the charging overvoltage protection drive signal is a third voltage, and the on and off of the charging switch is determined only by the level of the charging overvoltage protection drive signal.

[0008] In one possible implementation, the level conversion module includes: an inverter, configured to receive the charging overvoltage protection control signal, invert the charging overvoltage protection control signal, and send the charging overvoltage protection control signal and the reverse charging overvoltage protection control signal to a driving module; a driving module, coupled to the inverter, configured to receive the charging overvoltage protection control signal and the reverse charging overvoltage protection control signal, and perform level conversion on the charging overvoltage protection control signal to obtain a charging overvoltage protection driving signal.

[0009] In one possible implementation, when the charging overvoltage protection control signal is the first power supply voltage, the third power supply voltage is output after passing through the level conversion module; when the charging overvoltage protection control signal is the third power supply voltage, the second power supply voltage is output after passing through the level conversion module.

[0010] In a possible implementation, the driving module includes a first driving unit, a second driving unit, a third driving unit, and a fourth driving unit;

[0011] The first driving unit is coupled to the second driving unit and the third driving unit;

[0012] The second driving unit is coupled to the level conversion device and the fourth driving unit;

[0013] The third driving unit is coupled to the first driving unit, the fourth driving unit and the output end of the driving module;

[0014] The fourth driving unit is coupled to the level conversion module, the third driving unit and the output end of the driving module;

[0015] The second driving unit receives the reverse charging overvoltage protection control signal, and the fourth driving unit receives the charging overvoltage protection control signal.

[0016] In a possible implementation, the first driving unit includes a first MOS transistor, the second driving unit includes a second MOS transistor, the third driving unit includes a third MOS transistor, and the fourth driving unit includes a fourth MOS transistor;

[0017] The gate of the first MOS transistor is coupled to the drain of the third MOS transistor and the drain of the fourth MOS transistor, the source of the first MOS transistor is coupled to the second power supply voltage, and the drain of the first MOS transistor is coupled to the drain of the second MOS transistor and the gate of the third MOS transistor;

[0018] The gate of the second MOS transistor is coupled to the output terminal of the inverter, the source of the second MOS transistor is coupled to the third power supply voltage, and the drain of the second MOS transistor is coupled to the drain of the first MOS transistor and the gate of the second MOS transistor;

[0019] The gate of the third MOS transistor is coupled to the drain of the first MOS transistor and the drain of the second MOS transistor, the source of the third MOS transistor is coupled to the second power supply voltage, and the drain of the third MOS transistor is coupled to the gate of the first MOS transistor and the drain of the fourth MOS transistor;

[0020] The gate of the fourth MOS transistor is coupled to the input terminal of the inverter, the source of the fourth MOS transistor is coupled to the third power supply voltage, and the drain of the fourth MOS transistor is coupled to the drain of the third MOS transistor.

[0021] In one possible implementation, when the charging overvoltage protection control signal is the first power supply voltage, the fourth MOS transistor is turned on, the second MOS transistor is turned off, the third MOS transistor is turned off, and the first MOS transistor is turned on, so that the output end of the driving module outputs the third power supply voltage.

[0022] In one possible implementation, when the charging overvoltage protection control signal is the third power supply voltage, the fourth MOS transistor is turned off, the second MOS transistor is turned on, the second MOS transistor is turned on, the third MOS transistor is turned on, and the first MOS transistor is turned off, so that the output end of the driving module outputs the second power supply voltage.

[0023] In the second aspect, the present application also provides a battery system, comprising: a charging switch coupled in series with a battery pack, one end of which is coupled to a second power supply voltage; and a charging drive circuit as in the first aspect and its various implementations integrated in a battery protection chip, comprising: a battery detection module, configured to output a charging overvoltage protection control signal, the high-level voltage of the charging overvoltage protection control signal being the first power supply voltage; a level conversion module, which receives the charging overvoltage protection control signal and performs level conversion on the charging overvoltage protection control signal to obtain a charging overvoltage protection drive signal, the high-level voltage of the charging overvoltage protection drive signal being the second power supply voltage, the second power supply voltage being higher than the first power supply voltage, and a charging overvoltage protection pin, which outputs the charging overvoltage protection drive signal to the control end of the charging switch to control the conduction and cutoff of the charging switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure shows a schematic structural diagram of a battery protection circuit in the prior art;

[0025] Figure 2 It is a traditional driving circuit of a charging switch tube;

[0026] Figure 3 A schematic structural diagram of a charging drive circuit provided in an embodiment of the present application is shown;

[0027] Figure 4 A schematic diagram of a topological structure of a charging drive circuit provided in an embodiment of the present application is shown;

[0028] Figure 5 A structural schematic diagram of a battery system provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, and this is merely a way of distinguishing the objects of the same attributes when describing them in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0030] Unless otherwise specified, the words "coupled", "connected", "connected" and "connected" in this document that indicate electrical connection all mean direct or indirect connection. For example, "A and B are connected" includes both direct electrical connection between A and B and connection between A and B through electrical components or circuits.

[0031] In order to facilitate understanding of the technical solutions of the embodiments of the present application, the relevant terms involved in this document are explained below.

[0032] Open-Drain Pins: In circuit design, we often use General-Purpose Input / Output Ports (GPIO) to control peripheral circuits. GPIO ports have multiple configuration modes, including open-drain and push-pull output modes, and the corresponding pins are set to open-drain and push-pull types. An open-drain circuit is implemented by connecting an N-channel MOSFET between the internal output and ground, with the MOSFET's drain as the output. Open-drain circuits cannot output a high level; to do so, an external pull-up resistor must be connected. This means that open-drain circuits can only output leakage current. If you want to output source current, you need to add a pull-up resistor.

[0033] Push-Pull pin: A pin with internal pull-up and pull-down resistors, which includes two MOSFETs and can output high and low levels.

[0034] Figure 1 The figure shows a schematic diagram of the structure of the battery protection circuit of the prior art, which is provided for illustration and not limitation. The embodiment of the present application is described by taking the Seiko product S8254A and its peripheral circuit as an example. Figure 1 As shown in Figure 1, the battery protection circuit 100 includes a battery protection chip 200, a battery pack 300, and its peripheral circuits. The battery protection chip 200 has a built-in high-precision voltage detection circuit and delay circuit, which perform high-precision voltage detection on each battery cell, providing single-cell overcharge protection and single-cell over-discharge protection. It also has a three-stage overcurrent detection function, with the overcharge detection delay time, over-discharge detection delay time, and overcurrent detection delay time adjustable via external capacitors.

[0035] The negative electrode of the battery pack 300 is coupled to the seventh pin VSS of the battery protection chip 200 via the resistor Rvss and the capacitor Cvss, and can also serve as the ground terminal of the battery protection circuit 100 .

[0036] The battery protection chip 200 also includes some other pins, which are explained below:

[0037] COP: FET gate connection port for charge control (charge control terminal), NMOS open drain output

[0038] VMP: Voltage detection port

[0039] DOP: Discharge control FET gate connection port (discharge control terminal)

[0040] VSS: Negative power input port, negative voltage connection port of battery 4

[0041] VDD: Positive power input port, positive voltage connection port of battery 1

[0042] The battery protection circuit 100 includes a battery detection module (not shown), which is located in the battery protection chip 200. The battery detection module detects the output voltage and current of the battery pack 300. When the voltage and current of the battery pack exceed preset thresholds, the battery detection module sends overcharge or over-discharge protection control signals to the discharge control terminal DOP and the charge control terminal COP pins to control the conduction or cutoff of the charging switch tube M1 and the discharging switch tube M2.

[0043] The charging switch tube M1 and the discharging switch tube M2 are connected in series in the charging and discharging circuit of the battery pack 300. Figure 1 In the PCB, the charging switch M1 and the discharging switch M2 are connected in series between the positive terminal of the battery pack 300 and the output power port EB+. The charging switch M1 is coupled to the positive output terminal EB+ of the battery pack 300, and the discharging switch M2 is coupled to the positive terminal of the battery. The ports EB+ and EB- can be connected to a charger for charging or a load for discharging, thus providing the same charging and discharging ports.

[0044] A load is connected between the positive output terminal EB+ (or considered as the load output terminal EB+) and the negative output terminal EB- of the battery pack 300. When the battery pack 300 discharges to the load, when the battery detection module detects that any battery is over-discharged, it controls the battery protection chip 200 to enter the over-discharge protection mode, and the discharge control terminal DOP outputs a discharge overvoltage protection control signal to turn off the discharge switch tube M2, and the battery pack 300 stops discharging.

[0045] When the load is charging the battery pack 300, when the battery detection module detects that any battery is overcharged, it controls the battery protection chip 200 to enter the overcharge protection mode, and the charging control terminal COP outputs a charging overvoltage protection control signal to turn off the charging switch tube M1 and stop charging the battery pack 300.

[0046] After an overcharge or over-discharge state occurs, the battery protection circuit 100 will return to the normal operating mode after waiting for the battery pack to return to the normal voltage range.

[0047] The battery protection circuit 100 also includes a switching circuit. The switching circuit is inserted in series between the positive output terminal EB+ of the battery pack 300 and the positive output terminal of the battery pack 300. The switching circuit is, for example, a series circuit comprising a charging switch tube M1 and a discharging switch tube M2 connected in series. By disconnecting the charging switch tube M1, the positive-side charging path through which the charging current of the battery pack 300 flows is cut off, thereby preventing the flow of the charging current of the battery pack 300. By disconnecting the discharging switch tube M2, the positive-side discharging path through which the discharging current of the battery pack 300 flows is cut off, thereby preventing the flow of the discharging current of the battery pack 300.

[0048] The charging switch tube M1 and the discharging switch tube M2 are each, for example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The charging switch tube M1 is inserted into the charging and discharging path such that the forward direction of the parasitic diode of the charging switch tube M1 aligns with the discharging direction of the battery pack 300. The discharging switch tube M2 is inserted into the charging and discharging path such that the forward direction of the parasitic diode of the discharging switch tube M2 aligns with the charging direction of the battery pack 300. It should be noted that the charging path and the discharging path can be the same path. When the output voltage of the positive electrode of the battery pack 300 is higher than the voltage of the output terminal EB+ of the battery pack 300, the path from the positive electrode of the battery pack 300 through the switching circuit to the load output terminal EB+ is the charging path. When the output voltage of the positive electrode of the battery pack 300 is lower than the voltage of the load output terminal EB+, the path from the positive electrode of the battery pack 300 through the switching circuit to the load output terminal EB+ is the discharging path.

[0049] The charge control terminal COP outputs a signal to enable or disable charging of the battery pack and is coupled to the control terminal of the charge switch M1. The discharge control terminal DOP outputs a signal to enable or disable discharging of the battery pack 300 and is coupled to the control terminal of the discharge switch M2. The charge control terminal COP is a push-pull type pin, and its internal chip implementation circuit includes two MOS transistors. Under the influence of the high and low levels of the discharge control signal, the MOS transistors are alternately turned on and off, and the corresponding high and low levels are output from the discharge control terminal DOP to the control terminal of the discharge switch M2.

[0050] The charge control terminal COP is an open-drain type pin, which implements the circuit inside the chip as follows Figure 2 As shown, Figure 2This is a traditional driving circuit for a charging switch tube. The driving circuit includes an NMOS tube MN1. The gate of the MOS tube MN1 is coupled to the charging control signal COP_CTRL, and the source is coupled to the negative voltage VSS of the battery pack 300. Under the action of the charging control signal COP_CTRL, when the output value is set to a low level, the NMOS is turned on, and the output voltage of the charging control terminal COP is a low level. Because the open-drain type pin cannot output a high level, a pull-up resistor Rcop is added to the peripheral circuit of the battery protection circuit 100 to control the charging control terminal COP to output a high level, such as Figure 2 As shown, a pull-up resistor Rcop is connected in parallel with the charging switch tube M1. The load output terminal EB+ is coupled to the charging control terminal COP of the battery protection chip 200 through the pull-up resistor Rcop. In other words, when the charging control terminal COP is set to output a high level, the NMOS is in the off state. At this time, the output level of the charging control terminal COP depends on the external voltage. Through the external pull-up resistor, when the output is set to a high level, the voltage is pulled up to the power supply voltage of the pull-up resistor. When the output value is set to a low level, the NMOS is turned on, and the output level of the charging control terminal COP is a low level.

[0051] The embodiment of the present application changes the implementation method of the charging control terminal COP in the battery protection chip 200 outputting a high level, and the charging control terminal COP can output a high level without adding an external pull-up resistor. Figure 3 A schematic diagram of a charging drive circuit according to an embodiment of the present invention is shown below. Figure 1 and Figure 3 The function of the driving circuit is explained. The charging driving circuit 400 is actually a circuit with a level conversion function (level shifter). The input control signal of the driving circuit is the charging overvoltage protection control signal COP_CTRLCOP_CTRL, which converts the high-level charging overvoltage protection control signal COP_CTRLCOP_CTRL, that is, the first power supply voltage, into a third power supply voltage with the potential of the negative electrode of the battery pack 300 coupled to the battery protection core VSS terminal as a reference, and converts the low-level charging overvoltage protection control signal COP_CTRLCOP_CTRL, that is, the third power supply voltage into a second power supply voltage with the potential of the load output terminal EB+ as a reference. The first power supply voltage and the third power supply voltage are provided as charging overvoltage protection driving signals to the charging control terminal COP to turn on or off the charging switch tube M1. The charging control terminal COP defined in the embodiment of the present application is also the charging overvoltage protection pin. It should be noted that, Figure 3 The VCC in the figure can be regarded as the voltage generated by the battery protection chip pin VDD or VDD through the low voltage drop linear regulator LDO.

[0052] In one achievable embodiment, when the charge overvoltage protection control signal COP_CTRL is a low-level voltage, i.e., the third power supply voltage, it is converted to the second power supply voltage by the drive circuit, and the second power supply voltage controls the charging switch tube M1 to be turned off. When the charge overvoltage protection control signal COP_CTRL is a high-level voltage, i.e., the first power supply voltage, it is converted to the third power supply voltage by the drive circuit, and the third power supply voltage controls the charging switch tube M1 to be turned on.

[0053] It should be noted that the level of the charge overvoltage protection control signal COP_CTRL can be determined by any conventional solution, for example, by a signal detection circuit controlling the output of the charge overvoltage protection control signal COP_CTRL. The signal detection circuit can detect the voltage and current status of the battery pack 300 during charging and discharging. When the battery pack 300 is overcharged, the charge drive circuit in the battery protection chip 200 (i.e., from the load output terminal EB+ -> charge switch M1 -> discharge switch M2 -> -> the positive terminal of the battery pack 300) controls the charge switch M1 to be turned off, thereby cutting off the charge of the battery pack 300. Similarly, when the battery pack 300 is overdischarged, the discharge drive circuit in the battery protection chip 200 (i.e., from the positive terminal of the battery pack 300 -> discharge switch M2 -> charge switch M1 -> load output terminal EB+) controls the discharge switch M2 to be turned off, thereby cutting off the discharge of the battery pack 300.

[0054] The load's charging path is coupled to the battery pack 300 via the charging switch M1. When the signal detection circuit detects no overcharge, the charging overvoltage protection control signal COP_CTRL is high. After passing through the level conversion module in the charging driver circuit, the charging overvoltage protection drive signal COP is low, turning on the charging switch M1. This enables the load to charge from the load output terminal EB+ to the positive terminal of the battery pack 300. When the signal detection circuit detects overcharge, the charging overvoltage protection control signal COP_CTRL is low. After passing through the level conversion module in the charging driver circuit, the charging overvoltage protection drive signal COP is high, turning off the charging switch M1, thus disconnecting the charging path. This interrupts the charging current from the load to the positive terminal of the battery pack 300 through the load output terminal EB+. In this way, by varying the output signal of the charging control terminal COP, the charging path from the load output terminal EB+ through the charging switch M1 to the positive terminal of the battery pack 300 can be controlled, without requiring an external pull-up resistor within the battery protection chip 200.

[0055] In one possible implementation, the charging switch tube M1 is coupled to the load output terminal EB+ via a first terminal and to the discharge switch tube M2 via a second terminal. The charging switch tube M1 is configured to conduct the connection between the first terminal and the second terminal when the third terminal is at a third power supply voltage. When the third terminal is at a second power supply voltage, the connection between the first terminal and the second terminal is disconnected. In this way, the charging switch tube M1 is turned on or off by controlling the high or low logic level, without the need to provide a pull-up voltage through a pull-up resistor in a peripheral circuit. Because the pull-up resistor connected in parallel with the charging switch is removed, when charging the battery pack 300 from the load output terminal EB+, only the gate leakage current of the charging switch tube M1 will flow into the charging control terminal COP, which can effectively extend the effective standby time of the battery pack 300.

[0056] In a possible implementation, the charging switch tube M1 is a PMOS tube, the first end and the second end of the charging switch tube M1 are the source and the drain of the PMOS tube, and the third end is the gate of the PMOS tube.

[0057] The input end of the current detection module can be connected to the load output end EB+, for example. The battery protection chip 200 integrates the charging drive circuit provided in the embodiment of the present application, and the charging drive circuit is coupled to the charging switch tube M1.

[0058] Figure 4 FIG. 1 shows a topological structure diagram of a charging drive circuit provided in an embodiment of the present application, such as Figure 4 As shown, it is used to convert the signal of the charging control terminal COP into a driving signal effective for the charging switch tube M1 to control the conduction or disconnection of the charging switch tube M1. The gate of the charging switch tube M1 is coupled to the charging drive circuit 400. The charging drive circuit 400 includes an inverter 410, a driving unit 420 and a charging control terminal COP. The driving unit 420 includes a first driving unit 421, a second driving unit 422, a third driving unit 423 and a fourth driving unit 424. The inverter 410 is used to convert the charging overvoltage protection control signal COP_CTRL into an inverse overvoltage protection control signal, send the overvoltage protection control signal COP_CTRL to the second driving unit 422, and send the inverse overvoltage protection control signal to the fourth driving unit 424.

[0059] In one possible implementation, an input terminal of the inverter 410 is coupled to the overvoltage protection control signal COP_CTRL and the control terminal of the fourth driving unit 424 , and an output terminal thereof is coupled to the control terminal of the second driving unit 422 .

[0060] In one possible implementation, the first driver unit 421 includes a first PMOS transistor MP1 (also known as the first MOS transistor), the second driver unit 422 includes a second PMOS transistor MP2 (also known as the third MOS transistor), the third driver unit 423 includes a first NMOS transistor MN1 (also known as the second MOS transistor), and the fourth driver unit 424 includes a second NMOS transistor MN2 (also known as the fourth MOS transistor). The input of the inverter 410 is coupled to the gate of the second NMOS transistor MN2, and the output of the inverter 410 is coupled to the gate of the first NMOS transistor MN1. The drain of the first PMOS transistor MP1 and the drain of the first NMOS transistor MN1 are coupled to form a first drain connection point, which is then coupled to the gate of the second PMOS transistor MP2. The drain of the second PMOS transistor MP2 and the drain of the second NMOS transistor MN2 are coupled to form a second drain connection point, which is then coupled to the gate of the first PMOS transistor MP1. The source of the first PMOS transistor MP1 and the source of the second PMOS transistor MP2 are coupled to the load output terminal EB+ of the battery protection chip, and the source of the first NMOS transistor MN1 and the source of the second NMOS transistor MN2 are coupled to the negative voltage of the battery pack and the VSS terminal of the battery protection chip.

[0061] In the embodiment of the present application, the high level of the charging overvoltage protection control signal COP_CTRL is the first power supply voltage, that is, the voltage of the positive electrode of the battery pack 300 coupled to the VDD pin of the battery protection chip 200; the low level of the charging overvoltage protection control signal COP_CTRL is the third power supply voltage, that is, the voltage of the negative electrode of the battery pack 300 coupled to the VSS pin of the battery protection chip 200; the high level of the charging overvoltage protection drive signal COP is the second power supply voltage, that is, the voltage of the load output terminal EB+.

[0062] When the charge overvoltage protection control signal COP_CTRL is high, the second NMOS transistor MN2 is turned on. After passing through inverter 410, the charge overvoltage protection control signal COP_CTRL is inverted to a low level, turning off the first NMOS transistor MN1 and the second PMOS transistor. This turns on the first PMOS transistor, causing the second drain connection point to output a low level, turning on the charge switch M1. Because there is no pull-up resistor connected in parallel to the charge switch M1, only the current from the control terminal of the charge switch M1 flows into the charge control terminal COP. This solves the power loss caused by the prior art when the charge control terminal COP signal is pulled low during normal charging and discharging of the battery pack, resulting in current continuing to flow through the pull-up resistor.

[0063] When the overvoltage protection control signal COP_CTRL is low, the second NMOS transistor MN2 is turned off. After passing through inverter 410, the overvoltage protection control signal COP_CTRL becomes high, turning on the first NMOS transistor MN1. The second PMOS transistor MP2 is turned on, the first PMOS transistor MP1 is turned off, the second drain connection point outputs a high level, and the charging switch transistor M1 is turned off.

[0064] In one possible implementation, when the signal detection circuit detects that the voltage and current of the battery pack 300 are normal, the charge overvoltage protection control signal COP_CTRL outputs a high level. After passing through the driver circuit, the charge control terminal COP outputs a low level, controlling the charging switch M1 to conduct, thereby controlling the charging path. The battery pack 300 supplies power to the power output terminal EB+ through the charging path.

[0065] In one possible implementation, when the voltage and current of the battery pack 300 detected by the signal detection circuit exceed preset thresholds, the charge overvoltage protection control signal COP_CTRL outputs a low level. After passing through the driver circuit, the charge control terminal COP outputs a high level, controlling the charging switch M1 to turn off, thereby shutting off the charging path. The battery pack 300 cannot supply power to the power output terminal EB+ through the charging path. The charge drive circuit generates an output signal and transmits the output signal to the control terminal of the charge switch via the charge control terminal COP to control the charging switch to turn on or off.

[0066] This embodiment converts the overvoltage protection control signal, which swings from VSS to VCC, through the level shifter module LVL_SHIFT into an overvoltage protection drive signal, which swings from VSS to EB+, to drive the charging switch. This eliminates the pull-up resistor between the overvoltage protection drive signal and EB+ in the application circuit, reducing system power consumption.

[0067] The charging switch tube driving circuit in the embodiment of the present application can be used not only in a separately packaged battery protection chip, but also in a chip in which a battery protection chip and a charging switch tube are packaged together, or in a battery protection chip without peripheral circuits.

[0068] Therefore, in a second aspect, the embodiments of the present application further provide a battery system, Figure 5 A schematic diagram of the structure of a battery system provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the battery system 500 includes a charging switch 510 coupled in series with the battery pack and a charging drive circuit 520 integrated in the battery protection chip, wherein the charging drive circuit 520 is Figure 4The driving circuit shown. The charging driving circuit 520 includes a battery detection module configured to output a charging overvoltage protection control signal, wherein the high-level voltage of the charging overvoltage protection control signal is a first power supply voltage; a level conversion module, which receives the charging overvoltage protection control signal and performs level conversion on the charging overvoltage protection control signal to obtain a charging overvoltage protection driving signal, wherein the high-level voltage of the charging overvoltage protection driving signal is a second power supply voltage, which is higher than the first power supply voltage; and a charging overvoltage protection pin, which outputs the charging overvoltage protection driving signal to the control terminal of the charging switch to control the conduction and cutoff of the charging switch.

[0069] For the specific description of the second aspect in the embodiments of the present application, reference can be made to the detailed description of the mainboard in the first aspect and its various implementations; and for the beneficial effects of the second aspect and its various implementations, reference can be made to the analysis of the beneficial effects in the first aspect and its various implementations, which will not be repeated here.

[0070] For purposes of illustration and not limitation, the types of servers disclosed in the embodiments of the present application are not limited here, and may specifically be cabinet servers, tower servers, rack servers, and blade servers. In other words, the embodiments of the present application do not specifically limit the specific types of servers. Further, it is understood that, Figure 1 The structure of the server shown does not constitute a limitation on the structure of the server. The server may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0071] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0072] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A charging drive circuit, integrated into a battery protection chip, characterized in that: include: a battery detection module configured to output a charging overvoltage protection control signal, wherein a high-level voltage of the charging overvoltage protection control signal is a first power supply voltage; a level conversion module, which receives a charge overvoltage protection control signal and performs level conversion on the charge overvoltage protection control signal to obtain a charge overvoltage protection drive signal, wherein the high level voltage of the charge overvoltage protection drive signal is a second power supply voltage, which is higher than the first power supply voltage; The on and off of the charging switch is determined only by the level of the charging overvoltage protection driving signal; The level conversion module includes: an inverter configured to receive the charging overvoltage protection control signal, invert the charging overvoltage protection control signal, and send the charging overvoltage protection control signal and the inverse charging overvoltage protection control signal to a driving module; a driving module coupled to the inverter, configured to receive the charging overvoltage protection control signal and the reverse charging overvoltage protection control signal, and perform level conversion on the charging overvoltage protection control signal to obtain a charging overvoltage protection driving signal; the driving module includes a first driving unit, a second driving unit, a third driving unit, and a fourth driving unit; The first driving unit is coupled to the second driving unit and the third driving unit; The second driving unit is coupled to the level conversion device and the fourth driving unit; The third driving unit is coupled to the first driving unit, the fourth driving unit and the output end of the driving module; The fourth driving unit is coupled to the level conversion module, the third driving unit and the output end of the driving module; The second driving unit receives the reverse charging overvoltage protection control signal, and the fourth driving unit receives the charging overvoltage protection control signal; A charging overvoltage protection pin outputs the charging overvoltage protection driving signal to the control end of the charging switch to control the on and off of the charging switch.

2. The charging drive circuit according to claim 1, wherein: The low-level voltage of the charging overvoltage protection control signal is the third power supply voltage, and the low-level voltage of the charging overvoltage protection driving signal is the third power supply voltage.

3. The charging drive circuit according to claim 2, wherein: When the charging overvoltage protection control signal is the first power supply voltage, the third power supply voltage is output after passing through the level conversion module; When the charging overvoltage protection control signal is the third power supply voltage, the second power supply voltage is output after passing through the level conversion module.

4. The charging drive circuit according to claim 2, wherein: The first driving unit includes a first MOS transistor, the second driving unit includes a second MOS transistor, the third driving unit includes a third MOS transistor, and the fourth driving unit includes a fourth MOS transistor; The gate of the first MOS transistor is coupled to the drain of the third MOS transistor and the drain of the fourth MOS transistor, the source of the first MOS transistor is coupled to the second power supply voltage, and the drain of the first MOS transistor is coupled to the drain of the second MOS transistor and the gate of the third MOS transistor; The gate of the second MOS transistor is coupled to the output terminal of the inverter, the source of the second MOS transistor is coupled to the third power supply voltage, and the drain of the second MOS transistor is coupled to the drain of the first MOS transistor and the gate of the third MOS transistor; The gate of the third MOS transistor is coupled to the drain of the first MOS transistor and the drain of the second MOS transistor, the source of the third MOS transistor is coupled to the second power supply voltage, and the drain of the third MOS transistor is coupled to the gate of the first MOS transistor and the drain of the fourth MOS transistor; The gate of the fourth MOS transistor is coupled to the input terminal of the inverter, the source of the fourth MOS transistor is coupled to the third power supply voltage, and the drain of the fourth MOS transistor is coupled to the drain of the third MOS transistor.

5. The charging drive circuit according to claim 4, characterized in that: When the charging overvoltage protection control signal is the first power supply voltage, the fourth MOS transistor is turned on, the second MOS transistor is turned off, the third MOS transistor is turned off, and the first MOS transistor is turned on, so that the output end of the driving module outputs the third power supply voltage.

6. The charging drive circuit according to claim 4, characterized in that: When the charging overvoltage protection control signal is the third power supply voltage, the fourth MOS transistor is turned off, the second MOS transistor is turned on, the third MOS transistor is turned on, and the first MOS transistor is turned off, so that the output end of the driving module outputs the second power supply voltage.

7. A battery system comprising the charging drive circuit according to claim 1, characterized in that: include: a charging switch coupled in series with the battery pack, one end of which is coupled to a second power supply voltage; as well as The charging drive circuit integrated into the battery protection chip includes: a battery detection module configured to output a charging overvoltage protection control signal, wherein a high-level voltage of the charging overvoltage protection control signal is a first power supply voltage; a level conversion module, which receives a charging overvoltage protection control signal and performs level conversion on the charging overvoltage protection control signal to obtain a charging overvoltage protection drive signal, wherein the high level voltage of the charging overvoltage protection drive signal is a second power supply voltage, which is higher than the first power supply voltage, and the on and off of the charging switch is determined only by the level of the charging overvoltage protection drive signal; A charging overvoltage protection pin outputs the charging overvoltage protection driving signal to the control end of the charging switch to control the on and off of the charging switch.

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