Driving circuit, analog front-end control chip and battery management system

Abstract

The embodiment of the invention provides a driving circuit, an analog front-end control chip and a battery management system, and the circuit comprises a step-down circuit which is used for obtaining a control voltage according to an input voltage, and carrying out the step-down of the input voltage according to the control voltage, and obtaining an output voltage; and the voltage stabilizing circuit comprises a first resistor and a current mirror, the first resistor is used for adjusting the input current of the current mirror according to the change of the output voltage, and the current mirror is used for adjusting the control voltage according to the change of the input current so as to carry out voltage stabilizing control on the output voltage through the control voltage. The embodiment of the invention does not need to use a JFET device, can be suitable for various application scenes, and is simple in overall circuit structure and relatively low in power consumption.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a driving circuit, an analog front-end control chip and a battery management system. Background Art

[0002] The high-voltage to low-voltage circuit is a common electronic circuit widely used in various scenarios. At present, the simplest high-voltage to low-voltage circuit generally divides the voltage through series resistors, and converts the high voltage into the low voltage by using the proportional relationship of the resistors, but the output voltage of this circuit will change with the change of the input voltage. In order to keep the output voltage of the circuit at a stable voltage value, one way is to add a voltage regulator diode and a resistor to the circuit, clamp the output voltage, and control the output voltage through a transistor, but the output voltage of the voltage regulator diode is generally a positive temperature characteristic, and the threshold voltage of the transistor is generally a negative temperature characteristic, which leads to a large temperature coefficient of the output voltage. At the same time, the circuit also needs to use a high-voltage resistant JFET (Junction Field Effect Transistor) device, which makes the circuit design limited and limits the use scenario of the circuit. Another way is to use an LDO (Low Dropout Regulaor) structure to drive a bandgap reference voltage and an external bias current to generate a stable output voltage, but the circuit structure usually requires the use of an operational amplifier and a bandgap reference source, resulting in a complex circuit structure and a large chip area. Summary of the invention

[0003] In view of this, the present application provides a driving circuit, an analog front-end control chip and a battery management system to solve the problems in the prior art that the circuit design has limitations, the output voltage varies greatly with temperature, and the circuit structure is complex.

[0004] In a first aspect, an embodiment of the present application provides a driving circuit, including:

[0005] A step-down circuit, used for obtaining a control voltage according to an input voltage, and stepping down the input voltage according to the control voltage to obtain an output voltage;

[0006] A voltage stabilizing circuit comprises a first resistor and a current mirror, wherein the first resistor is used to adjust the input current of the current mirror according to the change of the output voltage, and the current mirror is used to adjust the control voltage according to the change of the input current, so as to perform voltage stabilization control on the output voltage through the control voltage.

[0007] The embodiment of the present application does not require the use of JFET devices, so that the circuit can be directly applied in most high-voltage to low-voltage scenarios. The embodiment of the present application realizes voltage regulation control of the output voltage through a first resistor and a current mirror. Compared with the negative feedback structure using an operational amplifier and a bandgap reference source, the circuit structure is simple and the power consumption is low. At the same time, the output voltage is highly stable and is not easily affected by temperature changes.

[0008] In a possible implementation, the voltage reduction circuit includes:

[0009] a voltage-dividing resistor, wherein a first end of the voltage-dividing resistor is electrically connected to the voltage input end, a second end of the voltage-dividing resistor is grounded via a first enabling switch, and the voltage-dividing resistor is used to receive an input voltage from the voltage input end and output a control voltage according to the input voltage;

[0010] A first transistor, wherein the first end of the first transistor is electrically connected to the voltage input end, the second end of the first transistor is electrically connected to the voltage output end, the control end of the first transistor is electrically connected to the output end of the voltage divider resistor, and the first transistor is used to receive the control voltage output by the voltage divider resistor and to step down the input voltage based on the control voltage to obtain an output voltage.

[0011] In an embodiment of the present application, the voltage-dividing resistor includes a second resistor and a third resistor connected in series, wherein the first end of the voltage-dividing resistor is the first end of the third resistor, the second end of the voltage-dividing resistor is the second end of the second resistor, and the output end of the voltage-dividing resistor is a node between the second resistor and the third resistor. Through the voltage-dividing resistor, the embodiment of the present application can control the control voltage input to the first transistor, thereby controlling the output voltage.

[0012] In a possible implementation manner, the output end of the voltage-dividing resistor is also electrically connected to the output end of the current mirror, so as to adjust the control voltage according to the output current of the current mirror.

[0013] In an embodiment of the present application, the output end of the voltage divider resistor is electrically connected to the output end of the current mirror. When the output current of the current mirror changes, the current flowing into the second resistor changes, causing the control voltage output by the output end of the voltage divider resistor to change, thereby further adjusting the output voltage based on the change in the control voltage.

[0014] In a possible implementation manner, the first enabling switch includes:

[0015] A second transistor, wherein the first end of the second transistor is electrically connected to the second end of the voltage-dividing resistor, the control end of the second transistor is used to receive a first enable signal, the second end of the second transistor is grounded, and the second transistor is used to input a first start signal according to the first enable signal when the drive circuit is started.

[0016] In the embodiment of the present application, the first enabling switch can input the first starting signal according to the first enabling signal when the driving circuit is started, so as to turn on the branch where the voltage dividing resistor is located, and the voltage dividing resistor starts to output the control signal.

[0017] In a possible implementation, the current mirror includes:

[0018] a first current mirror, wherein an input end of the first current mirror is electrically connected to the second end of the first resistor, and a first end of the first resistor is electrically connected to a voltage output end;

[0019] a second current mirror, wherein the input end of the second current mirror is electrically connected to the output end of the first current mirror, and the output end of the second current mirror is electrically connected to the output end of the voltage divider resistor of the step-down circuit;

[0020] When the input current changes, the first current mirror is used to adjust the output current of the second current mirror according to the change of the input current, so as to adjust the control voltage through the output current of the second current mirror.

[0021] In the embodiment of the present application, the current flowing into the second resistor can be better controlled by two sets of current mirrors to ensure control accuracy.

[0022] In a possible implementation, the first current mirror includes a third transistor and a fourth transistor, and the second current mirror includes a fifth transistor and a sixth transistor, wherein:

[0023] The first end of the third transistor is electrically connected to the second end of the first resistor, the control end of the third transistor is electrically connected to the first end of the third transistor, and the second end of the third transistor is grounded;

[0024] The first end of the fourth transistor is electrically connected to the second end of the fifth transistor, the control end of the fourth transistor is electrically connected to the control end of the third transistor, and the second end of the fourth transistor is grounded;

[0025] The first terminal of the fifth transistor is electrically connected to the voltage input terminal, and the control terminal of the fifth transistor is electrically connected to the second terminal of the fifth transistor;

[0026] The first end of the sixth transistor is electrically connected to the voltage input end, the control end of the sixth transistor is electrically connected to the control end of the fifth transistor, and the second end of the sixth transistor is electrically connected to the output end of the voltage divider resistor of the step-down circuit.

[0027] In the embodiment of the present application, the third transistor can be Figure 5 The NMOS transistor MN1 in the embodiment, the fourth transistor may be Figure 5 The NMOS transistor MN0 in the embodiment, the fifth transistor may be Figure 5 The PMOS transistor MP0 in the embodiment, the sixth transistor can be Figure 5 PMOS transistor MP1 in. When the output voltage increases and current is generated in MN1, corresponding currents will be generated in MN0, MP0 and MP1, and the currents in MN1, MN0, MP0 and MP1 will change with the change of the output voltage, thereby controlling the change of the control voltage outputted from the output end of the voltage divider resistor, and further controlling the change of the output voltage. For example, when the output voltage becomes higher, the current of the first resistor increases, and the currents in MN1, MN0, MP0 and MP1 also increase accordingly, causing the current flowing through the second resistor to increase, the control voltage to decrease, the gate-source voltage of the first transistor to decrease, and the output voltage to decrease; when the output voltage becomes lower, the current of the first resistor decreases, and the currents in MN1, MN0, MP0 and MP1 also decrease accordingly, causing the current flowing through the second resistor to decrease, the control voltage to increase, the gate-source voltage of the first transistor to increase, and the output voltage to increase.

[0028] In a possible implementation, the voltage stabilizing circuit further includes:

[0029] A voltage regulator diode, wherein a cathode of the voltage regulator diode is electrically connected to the second end of the first resistor, an anode of the voltage regulator diode is electrically connected to the input end of the first current mirror, and the voltage regulator diode is used to stabilize the output voltage within a set range.

[0030] In the embodiment of the present application, the use of a voltage stabilizing diode can stabilize the output voltage within a set range.

[0031] In a possible implementation, the voltage stabilizing circuit further includes:

[0032] A second enabling switch, wherein the second enabling switch comprises a seventh transistor, wherein a first end of the seventh transistor is electrically connected to the anode of the Zener diode, a control end of the seventh transistor is used to receive a second enabling signal, a second end of the seventh transistor is grounded, and the seventh transistor is used to output a second starting signal according to the second enabling signal when the driving circuit is started.

[0033] In an embodiment of the present application, the second enabling switch can input a second starting signal according to a second enabling signal when the driving circuit is started, so as to turn on the branch where the first resistor and the Zener diode are located, thereby ensuring the circuit safety after the Zener diode is broken down.

[0034] In a second aspect, an embodiment of the present application provides an analog front-end control chip, comprising a driving circuit as described in any one of the first aspects.

[0035] In a third aspect, an embodiment of the present application provides a battery management system, comprising an analog front-end control chip as described in any one of the second aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0037] Figure 1 It is a schematic diagram of a circuit structure of high voltage to low voltage conversion in the related art;

[0038] Figure 2 It is a schematic diagram of another circuit structure of high voltage to low voltage conversion in the related art;

[0039] Figure 3 A circuit block diagram of a driving circuit provided in an embodiment of the present application;

[0040] Figure 4 A circuit block diagram of another driving circuit provided in an embodiment of the present application;

[0041] Figure 5 A schematic diagram of a circuit structure of a driving circuit provided in an embodiment of the present application;

[0042] Figure 6 A structural block diagram of an analog front-end control chip provided in an embodiment of the present application;

[0043] Figure 7 A structural block diagram of a battery management system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0045] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0046] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0047] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0048] It should be understood that in the following description, "circuit" refers to a conductive loop composed of at least one element or subcircuit through electrical connection or electromagnetic connection. When an element or circuit is said to be "connected to" another element or an element / circuit is said to be "connected between" two nodes, it can be directly coupled or connected to another element or there can be an intermediate element, and the connection between the elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element between the two.

[0049] In the present application, a transistor is a semiconductor device that controls current, also known as a semiconductor transistor, a bipolar transistor or a crystal transistor. The first end and the second end of the transistor are respectively the high potential end and the low potential end on the current path, and the control end is used to receive a drive signal to control the output current of the transistor. The transistor can be divided into a PNP type and an NPN type. The first end, the second end and the control end of the PNP type are respectively the emitter, the collector and the base, and the first end, the second end and the control end of the NPN type are respectively the collector, the emitter and the base.

[0050] In the present application, a transistor is a transistor that operates in a linear mode to provide a current path, including one selected from a bipolar transistor or a field effect transistor. The first end and the second end of the transistor are respectively a high potential end and a low potential end on the current path, and the control end is used to receive a drive signal to control the voltage drop of the transistor. The transistor can be a P-type MOSFET or an N-type MOSFET. The first end, the second end and the control end of the P-type MOSFET are respectively a source, a drain and a gate, and the first end, the second end and the control end of the N-type MOSFET are respectively a drain, a source and a gate.

[0051] The high-voltage to low-voltage circuit is a common electronic circuit that is widely used in various scenarios. At present, the simplest high-voltage to low-voltage circuit generally divides the voltage through series resistors, using the proportional relationship of resistors to convert high voltage to low voltage, but the output voltage of this circuit will change with the input voltage.

[0052] In order to keep the output voltage of the circuit at a stable voltage value, one way is to add a voltage regulator diode and a resistor to the circuit to clamp the output voltage and control the output voltage through a transistor, such as Figure 1As shown, M1 is a JFET transistor with a high-voltage negative threshold voltage, and the voltage at the first end of the resistor r1 is the absolute value of the threshold voltage of M1. After the input high voltage is limited by the resistor r1, it is stabilized by the voltage regulator diode Z1, and a relatively stable voltage is obtained at the positive electrode of the voltage regulator diode Z1 as the gate drive voltage of the transistor M2. However, in this circuit, the output voltage of the voltage regulator diode Z1 generally has a positive temperature characteristic, that is, under the same conditions, the output voltage rises with the increase of temperature, and the threshold voltage of the transistor M2 generally has a negative temperature characteristic, that is, as the temperature increases, its threshold voltage decreases, which causes the output voltage Vout to have a large temperature coefficient. In addition, the circuit also needs to use a JFET (Junction Field Effect Transistor) device M1 with high-voltage resistance, which makes the circuit design limited and limits the use scenarios of the circuit. At the same time, due to Figure 1 It can be seen that there is no negative feedback in this circuit to adjust the output voltage. Therefore, when the output current becomes larger, the output voltage will be significantly reduced and the load capacity is weak.

[0053] Another way is to use LDO (Low Dropout Regulaor, low voltage difference linear regulator) structure to drive the bandgap reference voltage and external bias current to generate a stable output voltage, such as Figure 2 As shown, the bandgap reference voltage VBG is input to the positive phase end of the AMP, and the output voltage is sampled by dividing the voltage through resistors r3 and r4, and input to the negative phase end of the AMP for comparison with the bandgap reference voltage VBG, and the difference is used to control the gate voltage of the JFET tube, thereby adjusting the output voltage. Although this circuit uses a negative feedback structure to stabilize the output voltage, the negative feedback structure contains an operational amplifier and a bandgap reference source, resulting in a complex circuit structure and a large chip area.

[0054] In response to the above problems, the embodiments of the present application provide a driving circuit, an analog front-end control chip and a battery management system. The embodiments of the present application do not require the use of JFET devices and can be directly applied to most high-voltage to low-voltage scenarios. The embodiments of the present application achieve voltage regulation control of the output voltage through a first resistor and a current mirror. Compared with the negative feedback structure using an operational amplifier and a bandgap reference source, the circuit structure is simple and the power consumption is low. At the same time, the output voltage is highly stable and is not easily affected by temperature changes.

[0055] The following is a description with reference to the accompanying drawings.

[0056] See also Figure 3 , is a circuit block diagram of a driving circuit provided in an embodiment of the present application. Figure 3As shown, the driving circuit includes a step-down circuit 100 and a voltage stabilizing circuit 200, wherein the input end of the step-down circuit 100 is electrically connected to the voltage input end for receiving the input voltage Vbat, the output end of the step-down circuit 100 is electrically connected to the voltage output end for outputting the output voltage Vout, the input end of the voltage stabilizing circuit 200 is electrically connected to the voltage output end for obtaining the output voltage Vout, and the output end of the voltage stabilizing circuit 200 is electrically connected to the step-down circuit 100 for outputting current to the step-down circuit 100. During the operation of the driving circuit, the step-down circuit 100 is used to obtain a control voltage according to an input voltage Vbat, and to step down the input voltage Vbat according to the control voltage to obtain an output voltage Vout; the voltage stabilizing circuit 200 is used to adjust the output current according to changes in the output voltage Vout, so as to adjust the control voltage of the step-down circuit 100 based on the output current, thereby stabilizing the output voltage Vout through the control voltage, wherein the voltage stabilizing circuit 200 is also electrically connected to a voltage input terminal to receive an input voltage Vbat, and the input voltage Vbat is used to provide an operating voltage for the voltage stabilizing circuit 200.

[0057] In one possible implementation, Figure 4 As shown, the voltage stabilizing circuit 200 includes a first resistor 210 and a current mirror 220, wherein a first end of the first resistor 210 is electrically connected to the voltage output end, a second end of the first resistor 210 is electrically connected to the input end of the current mirror 220, and an output end of the current mirror 220 is electrically connected to the buck circuit 100. In a specific implementation, the first resistor 210 is used to adjust the input current of the current mirror according to the change of the output voltage, and the current mirror 220 is used to adjust the control voltage of the buck circuit 100 according to the change of the input current, so as to perform voltage stabilization control on the output voltage Vout through the control voltage.

[0058] The embodiment of the present application adds a voltage stabilizing circuit to the driving circuit, which can automatically adjust the output voltage and improve the stability of the output voltage. The voltage stabilizing circuit of the embodiment of the present application can achieve voltage stabilization control of the output voltage through a first resistor and a current mirror, without the need for an operational amplifier or a bandgap reference source. The overall structure is simple, the power consumption is low, and the reliability is high.

[0059] The following is a Figure 4 The circuit structure of each circuit is further explained.

[0060] See also Figure 5 , is a schematic diagram of a circuit structure of a driving circuit provided in an embodiment of the present application. Figure 5As shown, the step-down circuit 100 includes a voltage-dividing resistor 110 and a first transistor MPP, wherein the first end of the voltage-dividing resistor 110 is electrically connected to the voltage input end, the second end of the voltage-dividing resistor 110 is grounded through a first enabling switch, the first end of the first transistor MPP is electrically connected to the voltage input end, the second end of the first transistor MPP is electrically connected to the voltage output end, and the control end of the first transistor MPP is electrically connected to the output end of the voltage-dividing resistor 110. During the operation of the driving circuit, the voltage-dividing resistor 110 is used to receive an input voltage Vbat from the voltage input end, and obtain a control voltage after dividing the input voltage Vbat by voltage division, and output the control voltage. After receiving the control voltage, the control end of the first transistor MPP steps down the input voltage Vbat according to the control voltage to obtain an output voltage Vout.

[0061] In a possible implementation, the voltage-dividing resistor 110 includes a second resistor R2 and a third resistor R3, wherein a first end of the third resistor R3 is electrically connected to a voltage input end, a second end of the third resistor R3 is electrically connected to a first end of the second resistor R2, a second end of the second resistor R2 is grounded via a first enabling switch, and a node between the second resistor R2 and the third resistor R3 is an output end of the voltage-dividing resistor 110. In the embodiment of the present application, the magnitude of the output control voltage can be adjusted by adjusting the ratio of the second resistor R2 and the third resistor R3. In a specific implementation, the resistance value of the third resistor R3 is much greater than the resistance value of the second resistor R2, so that the control voltage is mainly affected by the second resistor R2, so that the control voltage output by the voltage-dividing resistor 110 can be adjusted in the subsequent circuit by controlling the current of the second resistor R2.

[0062] In a possible implementation, the output end of the voltage-dividing resistor 110 is also electrically connected to the output end of the current mirror 220, so as to adjust the control voltage output by the voltage-dividing resistor 110 according to the output current of the current mirror 220. Specifically, after the output end of the voltage-dividing resistor 110 is electrically connected to the output end of the current mirror 220, the output current of the current mirror 220 will flow through the second resistor R2 and then be grounded, that is, the current of the second resistor R2 will be affected by the output current of the current mirror 220, so that the voltage at the first end of the second resistor R2 will be affected by the output current of the current mirror 220, that is, the control voltage will be affected by the output current of the current mirror 220. Therefore, in practical applications, the control voltage output by the voltage-dividing resistor 110 can be adjusted by adjusting the output current of the current mirror 220.

[0063] In a possible implementation, the first enabling switch includes a second transistor MS0, a first end of the second transistor MS0 is electrically connected to the second end of the voltage-dividing resistor 110, that is, electrically connected to the second end of the second resistor R2, a control end of the second transistor MS0 is used to receive a first enabling signal en, and a second end of the second transistor MS0 is grounded, wherein Vss represents a ground signal. During the operation of the driving circuit, the second transistor MS0 is used to receive the first enabling signal en when the driving circuit is started, and input a first starting signal according to the first enabling signal en, so that the branch where the voltage-dividing resistor 110 is located is turned on, and the voltage-dividing resistor 110 starts to output a control signal.

[0064] Please continue reading Figure 5 .like Figure 5 As shown, the current mirror 220 includes a first current mirror and a second current mirror, wherein the input end of the first current mirror is electrically connected to the second end of the first resistor R1, the first end of the first resistor R1 is electrically connected to the voltage output end, the input end of the second current mirror is electrically connected to the output end of the first current mirror, and the output end of the second current mirror is electrically connected to the output end of the voltage divider resistor 110; wherein, when the output voltage of the voltage output end changes, the input current of the current mirror will change, that is, the input current of the first current mirror will change. At this time, the first current mirror is used to adjust the output current of the second current mirror according to the change of the input current, so as to adjust the control voltage through the output current of the second current mirror, thereby adjusting the output voltage of the voltage output end through the control voltage.

[0065] The embodiment of the present application can allow current to flow into the second resistor R2 through the setting of two current mirrors, thereby changing the control voltage output by the voltage divider resistor and achieving voltage stabilization control of the output voltage.

[0066] In a possible implementation, the first current mirror includes a third transistor MN1 and a fourth transistor MN0, and the second current mirror includes a fifth transistor MP0 and a sixth transistor MP1, wherein:

[0067] A first end of the third transistor MN1 is electrically connected to the second end of the first resistor R1, a control end of the third transistor MN1 is electrically connected to the first end of the third transistor MN1, and a second end of the third transistor MN1 is grounded; a first end of the fourth transistor MN0 is electrically connected to the second end of the fifth transistor MP0, a control end of the fourth transistor MN0 is electrically connected to the control end of the third transistor MN1, and a second end of the fourth transistor MN0 is grounded; a first end of the fifth transistor MP0 is electrically connected to the voltage input end, and a control end of the fifth transistor MP0 is electrically connected to the second end of the fifth transistor MP0; a first end of the sixth transistor MP1 is electrically connected to the voltage input end, a control end of the sixth transistor MP1 is electrically connected to the control end of the fifth transistor MP0, and a second end of the sixth transistor MP1 is electrically connected to the output end of the voltage-dividing resistor 110.

[0068] In the embodiment of the present application, when the output voltage Vout is small, there is no current in MN1, and correspondingly, there is no current in MN0, MP0 and MP1. When the output voltage Vou increases, so that the current is generated in MN1, MN0, MP0 and MP1 will also generate corresponding current, and the current in MN1, MN0, MP0 and MP1 will change with the change of the output voltage Vout, so that the control voltage outputted from the output end of the voltage-dividing resistor 110 changes, further causing the output voltage Vout to change. For example, when the output voltage Vout increases by more than the set value, the current of the first resistor R1 increases, and the current in MN1, MN0, MP0 and MP1 also increases accordingly, so that the current flowing through the second resistor R2 increases, the control voltage decreases, the gate-source voltage of the first transistor MPP decreases, and the output voltage Vout decreases; when the output voltage Vout decreases by less than the set value, the current of the first resistor R1 decreases, and the current in MN1, MN0, MP0 and MP1 also decreases accordingly, so that the current flowing through the second resistor R2 decreases, the control voltage increases, the gate-source voltage of the first transistor MPP increases, and the output voltage Vout increases. That is, the voltage stabilizing circuit composed of the first resistor R1 and the current mirror 220 in the embodiment of the present application can stabilize the output voltage Vout at a set value, thereby ensuring the stability of the output voltage and also enhancing the load-carrying capacity of the circuit.

[0069] In a specific implementation, a fourth resistor R4 may be provided on a connection line between the first end of the fourth transistor MN0 and the second end of the fifth transistor MP0, and the current in the second current mirror may be adjusted by the fourth resistor R4, thereby adjusting the current input to the second resistor R2, ensuring that the output control voltage is within a set range, and the current input to the second resistor R2 may be fine-tuned by the fourth resistor R4, ensuring the control accuracy of the output control voltage. At the same time, the fourth resistor R4 may also protect the circuit, thereby increasing the stability and reliability of the circuit.

[0070] In a specific implementation, a fifth resistor R5 may be connected in parallel to the fifth transistor MP0 to shunt the current of the fifth transistor MP0 through the fifth resistor R5 to ensure the stability and reliability of the circuit.

[0071] In a possible implementation, a voltage stabilizing diode D1 is further provided in the voltage stabilizing circuit 200, wherein the cathode of the voltage stabilizing diode D1 is electrically connected to the second end of the first resistor R1, and the anode of the voltage stabilizing diode D1 is electrically connected to the input end of the first current mirror, that is, the first end of the third transistor MN1. During the operation of the driving circuit, the voltage stabilizing diode D1 is used to stabilize the output voltage Vout within a set range. Specifically, when the output voltage Vout is less than the Zener breakdown voltage VD1 When the voltage regulator diode D1 is in the cut-off state, no current flows through the current mirror 220, and the output voltage Vout is in the rising state under the control of the control voltage output by the voltage divider resistor 110; when the output voltage Vout is greater than or equal to the Zener breakdown voltage V D1 At this time, the Zener diode D1 is broken down, but due to the threshold voltage of the third transistor MN1, no current flows through the current mirror 220, and the output voltage Vout is still in a rising state until the output voltage Vout is greater than or equal to the Zener breakdown voltage V D1 and the threshold voltage of the third transistor MN1, current will be generated in MN1, that is, current mirror 220 will have current output, so as to adjust the control voltage to step down the output voltage Vout through the control voltage; and when the output voltage Vout decreases, so that no current flows through MN1, the output voltage Vout returns to the rising state. Therefore, according to the Zener breakdown voltage V D1 The threshold voltage of the third transistor MN1 can control the adjustment range of the output voltage Vout, ensuring that the output voltage Vout is stable within the set range.

[0072] It is understandable that, due to the existence of the first resistor R1, in actual applications, the voltage at the second end of the first resistor R1 should be greater than or equal to the Zener breakdown voltage V of the voltage regulator diode D1. D1 and the threshold voltage of the third transistor MN1, the current can flow in the current mirror 220. However, since the voltage drop of the first resistor R1 is relatively large relative to the Zener breakdown voltage V D1 Therefore, the output voltage Vout can be directly considered to be equal to the voltage at the second end of the first resistor R1, that is, the output voltage Vout only needs to be greater than or equal to the Zener breakdown voltage V of the voltage regulator diode D1. D1 The sum of the threshold voltage of the transistor MN1 and the threshold voltage of the third transistor MN1 can make the current flow in the current mirror 220.

[0073] In a possible implementation, in order to ensure the stability and reliability of the circuit, a second enabling switch is further provided in the voltage stabilizing circuit 200, and the second enabling switch includes a seventh transistor MS1, a first end of the seventh transistor MS1 is electrically connected to the anode of the voltage stabilizing diode D1, a control end of the seventh transistor MS1 is used to receive a second enabling signal enn, and a second end of the seventh transistor MS1 is grounded. During the operation of the driving circuit, the seventh transistor MS1 is used to receive the second enabling signal enn when the driving circuit is started, and output a second starting signal according to the second enabling signal enn, so that the branch where the first resistor R1 and the voltage stabilizing diode D1 are located is turned on, thereby ensuring the circuit safety after the voltage stabilizing diode D1 is broken down.

[0074] In practical applications, the voltage regulator diode D1 and the current mirror 220 only stabilize the output voltage Vout within a set range. If the output voltage Vout needs to be at a set value, the resistance ratio of the first resistor R1 and the second resistor R2 needs to be adjusted.

[0075] In a specific implementation, the working principle of the driving circuit of the embodiment of the present application is as follows: after the power supply is powered on, the input voltage Vbat is turned on, the first enable switch and the second enable switch are turned on, at this time, there is no current in the mirror tube of the first current mirror composed of MN0 and MN1, so there is no current in the mirror tube of the second current mirror composed of MP0 and MP1. When the gate voltage (i.e., the control terminal voltage) of the first transistor MPP |Vgs| <V D1 When (V D1 The gate voltage of the first transistor MPP is provided with a start-up voltage by the branch where the second resistor R2 and the third resistor R3 are located. At this time, the first transistor MPP is turned on and the output voltage Vout rises. When the output voltage Vout rises to the Zener breakdown voltage V of the Zener diode D1, D1 When the voltage Vout is equal to the sum of the threshold voltage of the third transistor MN1, current will flow through MN1. Similarly, corresponding current will flow through MN0, MP0 and MP1. At this time, by reasonably selecting the resistance values ​​of the first resistor R1, the second resistor R2 and the third resistor R3, the required output voltage Vout can be obtained. The resistance value of the third resistor R3 is generally required to be much larger than the resistance value of the second resistor R2. Therefore, after the driving circuit is started, the influence of the third resistor R3 can be ignored, and only the resistance ratio of the first resistor R1 and the second resistor R2 needs to be adjusted.

[0076] Specifically, when the current mirror ratio is selected to be 1:1, we have:

[0077]

[0078] Simplifying formula (1) yields the output voltage:

[0079]

[0080] Where V bat is the input voltage, V out is the output voltage, V gs_MPP is the gate-source voltage of the first transistor MPP, V gs_MN1 is the gate-source voltage of the third transistor MN1, V D1 is the Zener breakdown voltage of the voltage regulator diode D1, which can be obtained from the process manual.

[0081] For V gs_MPP and V gs_MN1 The calculation formula is as follows

[0082]

[0083] Where V th_MPP , μ p and C oxp is the process parameter of the first transistor MPP, V th_MN1 , μ n and C oxn are the process parameters of the third transistor MN1, which can be obtained from the process manual. out is the output current of the driving circuit, L MPP is the channel length of the first transistor MPP, W MPP is the channel width of the first transistor MPP, L MN1 is the channel length of the third transistor MN1, W Mn1 is the channel width of the third transistor MN1 . The channel length and the channel width may be determined by the designer.

[0084] According to formula (2), the output voltage V out In the specific calculation process, we can ignore the second term in formula (3) and formula (4), that is, ignore and Get the output voltage V out After that, the output voltage V out Substitute into formula (1) to obtain I R2 Calculate, and then use formula (3) and formula (4) to get V gs_MPP and V gs_MN1 Then, according to formula (2), the output voltage V out .

[0085] According to the above derivation process, the final output voltage V out The output voltage is determined by the resistance ratio of the first resistor R1 and the second resistor R2. Therefore, the desired output voltage can be obtained by adjusting the resistance ratio of the first resistor R1 and the second resistor R2. That is, the embodiment of the present application can control the output voltage through the voltage divider network composed of the first resistor R1 and the second resistor R2.

[0086] In a possible implementation, a clamping protection circuit and a loop compensation circuit may be provided in the driving circuit to ensure the stability and reliability of the output voltage. Figure 5As shown, the clamping protection circuit includes a voltage-stabilizing diode D0, and the loop compensation circuit includes a resistor R0 and a capacitor C0, wherein the cathode of the voltage-stabilizing diode D0 is electrically connected to the first end of the first transistor MPP, the anode of the voltage-stabilizing diode D0 is electrically connected to the output end of the voltage-dividing resistor 110, that is, the first end of the second resistor R2, the first end of the resistor R0 is electrically connected to the second end of the capacitor C0, the second end of the resistor R0 is electrically connected to the output end of the voltage-dividing resistor 110, and the first end of the capacitor C0 is electrically connected to the first end of the first transistor MPP. During the operation of the driving circuit, the voltage-stabilizing diode D0 is used to clamp the output voltage, and the resistor R0 and the capacitor C0 are used to compensate the output voltage, thereby ensuring the stability and reliability of the output voltage.

[0087] It can be seen from the above description that the driving circuit provided in the embodiment of the present application includes the following technical effects:

[0088] 1. It does not rely on JFET devices, has high output voltage stability, is not easily affected by temperature changes, and can be used in various high-voltage to low-voltage scenarios;

[0089] 2. No operational amplifier and bandgap reference source are required in the voltage stabilization circuit, the circuit structure is simple, the power consumption is low, and the chip area is small;

[0090] 3. Lower static power consumption can be achieved by reasonably selecting the resistance values ​​of the first resistor, the second resistor and the third resistor.

[0091] Corresponding to the above embodiment, the embodiment of the present application also provides an analog front-end control chip.

[0092] See also Figure 6 , is a structural block diagram of an analog front-end control chip provided in an embodiment of the present application. Figure 6 As shown, the analog front-end control chip 600 includes a driving circuit 610. The specific content of the driving circuit 610 can be found in the description of the above embodiment, and will not be repeated here for the sake of brevity.

[0093] In a specific implementation, the analog front-end control chip may be, for example, a control module, a microcontroller unit (MCU), a digital signal processor (DSP), a microprocessor (MPU), a micro CPU, or the like, which can process digital signals, analog signals, or perform signal control functions, instruction processing, and calculation functions, and may be a micro central control chip or system-on-chip chip.

[0094] Corresponding to the above embodiment, the embodiment of the present application also provides a battery management system.

[0095] See also Figure 7 , is a structural block diagram of a battery management system provided in an embodiment of the present application. Figure 7 As shown, the battery management system 7700 includes an analog front-end control chip 600. The specific content of the analog front-end control chip 600 can refer to the description of the above embodiment, and for the sake of simplicity, it will not be repeated here.

[0096] Corresponding to the above embodiment, the embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium may store a program, wherein when the program is running, the device where the computer-readable storage medium is located may be controlled to perform some or all of the steps in the above method embodiment. In a specific implementation, the computer-readable storage medium may be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM).

[0097] Corresponding to the above-mentioned embodiment, the embodiment of the present application further provides a computer program product, which includes executable instructions. When the executable instructions are executed on a computer, the computer executes some or all of the steps in the above-mentioned method embodiment.

[0098] In the embodiments of the present application, "at least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0099] Those of ordinary skill in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented in a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present application.

[0100] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0101] In several embodiments provided in the embodiments of the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (read-only memory, referred to as ROM), random access memory (random access memory, referred to as RAM), disk or optical disk and other media that can store program code.

[0102] The above is only a specific implementation of the embodiment of the present application. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the embodiment of the present application, which should be included in the protection scope of the embodiment of the present application. The protection scope of the embodiment of the present application shall be based on the protection scope of the claims.

Claims

1. A driving circuit, characterized in that: include: A step-down circuit, used for obtaining a control voltage according to an input voltage, and stepping down the input voltage according to the control voltage to obtain an output voltage; A voltage stabilizing circuit comprises a first resistor and a current mirror, wherein the first resistor is used to adjust the input current of the current mirror according to the change of the output voltage, and the current mirror is used to adjust the control voltage according to the change of the input current, so as to perform voltage stabilization control on the output voltage through the control voltage.

2. The driving circuit according to claim 1, characterized in that: The step-down circuit comprises: a voltage-dividing resistor, wherein a first end of the voltage-dividing resistor is electrically connected to the voltage input end, a second end of the voltage-dividing resistor is grounded via a first enabling switch, and the voltage-dividing resistor is used to receive an input voltage from the voltage input end and output a control voltage according to the input voltage; A first transistor, wherein the first end of the first transistor is electrically connected to the voltage input end, the second end of the first transistor is electrically connected to the voltage output end, the control end of the first transistor is electrically connected to the output end of the voltage divider resistor, and the first transistor is used to receive the control voltage output by the voltage divider resistor and to step down the input voltage based on the control voltage to obtain an output voltage.

3. The driving circuit according to claim 2, characterized in that: The output end of the voltage-dividing resistor is also electrically connected to the output end of the current mirror, so as to adjust the control voltage according to the output current of the current mirror.

4. The driving circuit according to claim 2, characterized in that: The first enabling switch comprises: A second transistor, wherein the first end of the second transistor is electrically connected to the second end of the voltage-dividing resistor, the control end of the second transistor is used to receive a first enable signal, the second end of the second transistor is grounded, and the second transistor is used to input a first start signal according to the first enable signal when the drive circuit is started.

5. The driving circuit according to claim 1, characterized in that: The current mirror comprises: a first current mirror, wherein an input end of the first current mirror is electrically connected to the second end of the first resistor, and a first end of the first resistor is electrically connected to a voltage output end; a second current mirror, wherein the input end of the second current mirror is electrically connected to the output end of the first current mirror, and the output end of the second current mirror is electrically connected to the output end of the voltage divider resistor of the step-down circuit; When the input current changes, the first current mirror is used to adjust the output current of the second current mirror according to the change of the input current, so as to adjust the control voltage through the output current of the second current mirror.

6. The driving circuit according to claim 5, characterized in that: The first current mirror includes a third transistor and a fourth transistor, and the second current mirror includes a fifth transistor and a sixth transistor, wherein: The first end of the third transistor is electrically connected to the second end of the first resistor, the control end of the third transistor is electrically connected to the first end of the third transistor, and the second end of the third transistor is grounded; The first end of the fourth transistor is electrically connected to the second end of the fifth transistor, the control end of the fourth transistor is electrically connected to the control end of the third transistor, and the second end of the fourth transistor is grounded; The first terminal of the fifth transistor is electrically connected to the voltage input terminal, and the control terminal of the fifth transistor is electrically connected to the second terminal of the fifth transistor; The first end of the sixth transistor is electrically connected to the voltage input end, the control end of the sixth transistor is electrically connected to the control end of the fifth transistor, and the second end of the sixth transistor is electrically connected to the output end of the voltage divider resistor of the step-down circuit.

7. The driving circuit according to claim 5, characterized in that: The voltage stabilizing circuit further includes: A voltage regulator diode, wherein a cathode of the voltage regulator diode is electrically connected to the second end of the first resistor, an anode of the voltage regulator diode is electrically connected to the input end of the first current mirror, and the voltage regulator diode is used to stabilize the output voltage within a set range.

8. The driving circuit according to claim 7, characterized in that: The voltage stabilizing circuit further includes: A second enabling switch, wherein the second enabling switch comprises a seventh transistor, wherein a first end of the seventh transistor is electrically connected to the anode of the Zener diode, a control end of the seventh transistor is used to receive a second enabling signal, a second end of the seventh transistor is grounded, and the seventh transistor is used to output a second starting signal according to the second enabling signal when the driving circuit is started.

9. An analog front-end control chip, characterized in that: The invention comprises a driving circuit as claimed in any one of claims 1 to 8.

10. A battery management system, characterized in that: Comprising the analog front-end control chip as claimed in claim 9.

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