A voltage gating circuit and voltage detection device

Abstract

The application relates to the technical field of battery voltage detection, and discloses a voltage gating circuit and a voltage detection device, which are used for gating the output voltage output of at least one battery cell. The voltage gating circuit comprises a plurality of first level conversion circuits, a second level conversion circuit and a plurality of gating switch circuits. When any gating switch circuit needs to be turned on, the first level conversion circuit connected with the gating switch circuit outputs a first conduction signal after boosting the input voltage of the gating switch circuit based on a gating signal, meanwhile, the second level conversion circuit outputs a second conduction signal after boosting the output voltage of the gating switch circuit based on the gating signal, and then the gating switch circuit is turned on based on the first conduction signal and the second conduction signal. The gating switch circuit of the application can avoid the risk of breakdown of the gating switch circuit without using a thick gate oxide high-voltage MOS, and improves the process selection range of the voltage gating circuit.

Description

Technical Field

[0001] This invention relates to the field of battery voltage detection technology, specifically to a voltage gating circuit and a voltage detection device. Background Technology

[0002] The multi-cell battery protection chip needs to detect the voltage of each cell, so the voltage of each cell needs to be introduced into the voltage detection module through a selector switch. Since the cells are connected in series, when each cell has an output, the selector switch needs to be able to withstand the sum of the output voltages of the multiple cells, that is, it needs to have high voltage withstand capability.

[0003] In related technologies, high-voltage symmetrical MOSFETs with thick gate oxide are typically used to form voltage gating circuits. However, many monolithic integrated process technologies (Bipolar-CMOS-DMOS, BCD) only provide LDMOS with thin gate oxide, which makes multi-cell battery protection chips highly dependent on high-voltage MOSFETs with thick gate oxide, greatly limiting the range of process options. Summary of the Invention

[0004] In view of this, the present invention provides a voltage gating circuit and a voltage detection device to solve the problem that the gating switch in the existing voltage gating circuit is easily broken down by high voltage.

[0005] In a first aspect, the present invention provides a voltage gating circuit for selecting the output voltage of at least one battery cell. The voltage gating circuit includes: multiple first level conversion circuits, second level conversion circuits, and multiple gating switch circuits. Each first level conversion circuit receives one of multiple switch control signals at its input terminal, and the second level conversion circuit receives multiple switch control signals at its input terminal. The first control terminal of each gating switch circuit is connected to the output terminal of a first level conversion circuit, and the input terminal of each gating switch circuit is connected to the first terminal of a first level conversion circuit and receives the output voltage of one battery cell. The second control terminal of each gating switch circuit is connected to a corresponding output terminal of the second level conversion circuit, and the output terminal of each gating switch circuit is connected to the second level conversion circuit. The first terminal of the level conversion circuit is connected; when any selector switch circuit needs to be turned on, the first level conversion circuit connected to the selector switch circuit boosts or bucks the input voltage of the selector switch circuit based on the corresponding switch control signal and outputs a first turn-on signal. At the same time, the second level conversion circuit boosts or bucks the output voltage of the selector switch circuit based on the corresponding switch control signal of the selector switch circuit and outputs a second turn-on signal. Then the selector switch circuit is turned on based on the first turn-on signal and the second turn-on signal. At this time, all other selector switch circuits are turned off. When any selector switch circuit is turned off, the voltage difference between the first control terminal and its input terminal of the selector switch circuit, and the voltage difference between the output terminal and its second control terminal of the selector switch circuit are both less than the breakdown voltage of the switch in the selector switch circuit.

[0006] The voltage gating circuit provided by this invention has a first conduction signal obtained by boosting the input voltage of the gating switch circuit, and the voltage between the first conduction signal and the input of the gating switch circuit is less than the breakdown voltage of the switch within the gating switch circuit; the second conduction signal is obtained by boosting the output voltage of the gating switch circuit, and the voltage between the second conduction signal and the output of the gating switch circuit is less than the breakdown voltage of the switch within the gating switch circuit; therefore, neither of the two conduction signals controlling the gating switch circuit will exceed the breakdown voltage drop of the switch within the gating switch circuit, greatly reducing the risk of breakdown. The gating switch circuit does not need to use a thick-gate oxide high-voltage MOS switch to prevent breakdown, reducing the dependence of the voltage gating circuit on thick-gate oxide high-voltage MOS switches and improving the range of process options for circuit design.

[0007] In one optional implementation, when any selector switch circuit needs to be turned off, a first level conversion circuit connected to the selector switch circuit outputs a first turn-off signal after stepping down or boosting the input voltage of the selector switch circuit based on the corresponding switch control signal. Simultaneously, a second level conversion circuit outputs a second turn-off signal after stepping down or boosting the output voltage of the selector switch circuit based on the corresponding switch control signal. Then, the selector switch circuit is turned off based on the first and second turn-off signals. When the switch control signal is at a first logic level, it indicates that the corresponding selector switch circuit needs to be turned on; when the switch control signal is at a second logic level, it indicates that the corresponding selector switch circuit needs to be turned off. The first logic level and the second logic level are opposite.

[0008] In one optional embodiment, each selector switch circuit includes: a first controllable switch and a second controllable switch, wherein a first terminal of the first controllable switch receives the output voltage of a battery cell, a second terminal of the first controllable switch is connected to the first terminal of the second controllable switch, and a control terminal of the first controllable switch is connected to the output terminal of a first level conversion circuit connected to the battery cell; a second terminal of the second controllable switch is connected to the first terminal of a second level conversion circuit, and a control terminal of the second controllable switch is connected to an output terminal of the second level conversion circuit; the first controllable switch and the second controllable switch are turned on based on a first turn-on signal and a second turn-on signal, respectively; the first controllable switch and the second controllable switch are turned off based on a first turn-off signal and a second turn-off signal, respectively; when the first controllable switch is turned off, the voltage difference between the control terminal and the first terminal of the first controllable switch is less than the breakdown voltage of the first controllable switch; when the second controllable switch is turned off, the voltage difference between the second terminal and the control terminal of the second controllable switch is less than the breakdown voltage of the second controllable switch.

[0009] The voltage gating circuit provided by this invention has two controllable switches in each gating switch circuit. When the voltage at the input terminal and the output terminal of the gating switch circuit are inconsistent, one of the switches can switch to the cut-off state based on the voltage difference and bear most of the voltage drop between the input terminal and the output terminal of the gating switch circuit, thereby avoiding the breakdown and failure of the entire gating switch circuit and improving the reliability of the circuit.

[0010] In one optional embodiment, each first level conversion circuit includes: a first voltage regulating unit, a second voltage regulating unit, and a first output unit. The input terminal of the first voltage regulating unit is connected to the input terminal of the second voltage regulating unit and the input terminal of a corresponding gating switch circuit. The output terminal of the first voltage regulating unit is connected to the first input terminal of the first output unit. The first voltage regulating unit is used to boost the input voltage of the gating switch circuit and output a first reference voltage. The output terminal and the first terminal of the second voltage regulating unit are respectively connected to the second input terminal and the first terminal of the first output unit. The second voltage regulating unit is used to depress the input voltage of the gating switch circuit and output a second reference voltage. The output terminal of the first output unit is connected to the first control terminal of a corresponding gating switch circuit. The control terminal of the first output unit is connected to a corresponding switch control signal. The first output unit is used to output a first turn-on signal based on the corresponding switch control signal and the first reference voltage, or to output a first turn-off signal based on the corresponding switch control signal and the second reference voltage.

[0011] In one optional embodiment, the first voltage regulating unit includes: a first current source, a first voltage regulating unit, and a first voltage follower unit. The first terminal of the first voltage regulating unit is connected to the first terminal of the first voltage follower unit and the first terminal of the first current source, and outputs a first reference voltage. The second terminal of the first voltage regulating unit is connected to the input terminal of a gating switch circuit. The magnitude of the first reference voltage is adjusted by regulating the parameters of the voltage regulating device within the first voltage regulating unit. The second terminal of the first voltage follower unit is connected to the second terminal of the first current source. The third terminal of the first voltage follower unit is connected to the first input terminal of the first output unit. The first voltage follower unit is used to improve the driving capability of the first reference voltage. The first reference voltage is equal to the sum of the voltage drop of the first voltage regulating unit itself and the input voltage of the gating switch circuit.

[0012] The voltage gating circuit provided by this invention enables the first voltage follower unit to change from a high-impedance output node to a low-impedance output node, thereby improving the driving capability of the first reference voltage.

[0013] In one optional embodiment, the second voltage regulating unit includes a second current source and a second voltage regulating unit, wherein a first terminal of the second voltage regulating unit is connected to the input terminal of a gating switch circuit, a second terminal of the second voltage regulating unit is connected to the first terminal of the second current source and the second input terminal of the first output unit and outputs a second reference voltage, and the magnitude of the second reference voltage is adjusted by adjusting the parameters of the voltage regulating device in the second voltage regulating unit; the second terminal of the second current source is connected to the first terminal of the first output unit; the second reference voltage is equal to the difference between the input voltage of the gating switch circuit and the voltage drop of the second voltage regulating unit itself.

[0014] In one optional embodiment, the first output unit includes a first output driving unit and a second output driving unit, wherein a first terminal of the first output driving unit is connected to the output terminal of the first voltage regulating unit, a second terminal of the first output driving unit is connected to the first terminal of the second output driving unit and a first control terminal of a corresponding gating switch circuit, and the first output driving unit is used to convert a first reference voltage into a first conduction signal based on a corresponding switch control signal; the second terminal and the third terminal of the second output driving unit are respectively connected to the output terminal and the first terminal of the second voltage regulating unit, and the fourth terminal of the second output driving unit is connected to a corresponding switch control signal, and the second output driving unit is used to convert a second reference voltage into a first turn-off signal based on the corresponding switch control signal; when the switch control signal is at a first logic level, the first output driving unit converts the first reference voltage into a first conduction signal; when the switch control signal is at a second logic level, the second output driving unit converts the second reference voltage into a first turn-off signal.

[0015] In one optional embodiment, the second level conversion circuit includes: a third voltage regulating unit, a fourth voltage regulating unit, and a second output unit. The input terminal of the third voltage regulating unit is connected to the input terminal of the fourth voltage regulating unit and the output terminal of each gating switch circuit. The output terminal of the third voltage regulating unit is connected to the first input terminal of the second output unit. The third voltage regulating unit is used to boost the output voltage of the gating switch circuit and output a third reference voltage. The output terminal and the first terminal of the fourth voltage regulating unit are respectively connected to the second input terminal and the first terminal of the second output unit. The fourth voltage regulating unit is used to depress the output voltage of the gating switch circuit and output a fourth reference voltage. One of the multiple input terminals of the second output unit is input with one of a plurality of switch control signals. One of the multiple output terminals of the second output unit is connected to the second control terminal of a corresponding gating switch circuit. The second output unit is used to output a second turn-on signal of the corresponding gating switch circuit based on the corresponding switch control signal and the third reference voltage, or to output a second turn-off signal of the corresponding gating switch circuit based on the corresponding switch control signal and the fourth reference voltage.

[0016] In one optional embodiment, the third voltage regulating unit includes: a third current source, a third voltage regulating unit, and a second voltage follower unit. The first terminal of the third voltage regulating unit is connected to the first terminal of the second voltage follower unit and the first terminal of the third current source, and outputs a third reference voltage. The second terminal of the third voltage regulating unit is connected to the output terminal of each gating switch circuit. The magnitude of the third reference voltage is adjusted by regulating the parameters of the voltage regulating device within the third voltage regulating unit. The second terminal of the second voltage follower unit is connected to the second terminal of the third current source, and the third terminal of the second voltage follower unit is connected to the first input terminal of the second output unit. The second voltage follower unit is used to improve the driving capability of the third reference voltage. The third reference voltage is equal to the sum of the voltage drop of the third voltage regulating unit itself and the output voltage of the gating switch circuit.

[0017] The voltage gating circuit provided by this invention enables the second voltage follower unit to change from a high-impedance output node to a low-impedance output node, thereby improving the driving capability of the third reference voltage.

[0018] In one optional embodiment, the fourth voltage regulating unit includes: a fourth current source and a fourth voltage regulating unit, wherein the first terminal of the fourth voltage regulating unit is connected to the output terminal of a gating switch circuit, the second terminal of the fourth voltage regulating unit is connected to the first terminal of the fourth current source and the second input terminal of the second output unit and outputs a fourth reference voltage, and the magnitude of the fourth reference voltage is adjusted by adjusting the parameters of the voltage regulating device in the fourth voltage regulating unit; the second terminal of the fourth current source is connected to the first terminal of the second output unit; the fourth reference voltage is equal to the difference between the output voltage of the gating switch circuit and the voltage drop of the fourth voltage regulating unit itself.

[0019] In one optional embodiment, the second output unit includes: a plurality of output driving branches, wherein each output driving branch includes an output terminal, the output terminal of each output driving branch is connected to a second control terminal of a corresponding gating switch circuit, the control terminal of each output driving branch is connected to a corresponding switch control signal, the first terminal of each output driving branch is connected to the output terminal of a third voltage regulating unit and receives a third reference voltage, the second terminals of each output driving branch are interconnected and then connected to the output terminal of the third voltage regulating unit, the second terminal of each output driving branch is connected to the output terminal of a fourth voltage regulating unit and receives a fourth reference voltage, and each output driving branch outputs a second turn-on signal of the corresponding gating switch circuit based on a corresponding switch control signal and a third reference voltage, or outputs a second turn-off signal of the corresponding gating switch circuit based on a corresponding switch control signal and a fourth reference voltage; each output driving branch includes a third output terminal. The system includes a third output drive unit and a fourth output drive unit. The first terminal of the third output drive unit is connected to the output terminal of the third voltage regulation unit and receives a third reference voltage. The second terminal of the third output drive unit is connected to the first terminal of the fourth output drive unit and the second control terminal of a corresponding gating switch circuit. The third output drive unit is used to convert the third reference voltage into a second on signal based on a corresponding switch control signal. The second terminal of the fourth output drive unit is connected to the output terminal of the fourth voltage regulation unit. The third terminal of the fourth output drive unit is connected to a corresponding switch control signal. The fourth output drive unit is used to convert the fourth reference voltage into a second off signal based on the corresponding switch control signal. When the switch control signal is at a first logic level, the third output drive unit converts the third reference voltage into a second on signal; when the switch control signal is at a second logic level, the fourth output drive unit converts the fourth reference voltage into a second off signal.

[0020] Secondly, the present invention provides a voltage detection circuit, comprising: a control module, a voltage detection module, and a voltage gating circuit according to the first aspect or any corresponding embodiment thereof, wherein the output terminal of the control module is connected to the input terminal of each first level conversion circuit and the input terminal of each second level conversion circuit, and the control module is used to output multiple switch control signals; the input terminal of the voltage detection module is connected to the output terminal of each gating switch circuit, and the voltage detection module is used to detect the input voltage; when it is necessary to detect the output voltage of any cell, after the first level conversion circuit connected to the cell outputs a first conduction signal based on the corresponding switch control signal and the second level conversion circuit outputs a second conduction signal, the gating switch circuit connected to the cell is turned on and outputs the output voltage of the cell.

[0021] The voltage detection circuit provided by this invention obtains a first conduction signal by boosting the input voltage of the gating switch circuit, and the voltage between the first conduction signal and the input of the gating switch circuit is less than the breakdown voltage of the switch within the gating switch circuit; the second conduction signal is obtained by boosting the output voltage of the gating switch circuit, and the voltage between the second conduction signal and the output of the gating switch circuit is less than the breakdown voltage of the switch within the gating switch circuit; when the output voltage of multiple cells is detected simultaneously, regardless of the total output voltage, the two conduction signals controlling the gating switch circuit will not exceed the breakdown voltage drop of the switch within the gating switch circuit, greatly reducing the risk of breakdown. The gating switch circuit does not need to use a thick-gate oxide high-voltage MOS switch to prevent breakdown, reducing the dependence of the voltage gating circuit on thick-gate oxide high-voltage MOS switches and improving the process selection range of circuit design. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a gating circuit in a related technology;

[0024] Figure 2 This is a schematic diagram of a voltage gating circuit according to an embodiment of the present invention;

[0025] Figure 3 This is a specific circuit structure diagram of a gating switch circuit according to an embodiment of the present invention;

[0026] Figure 4 This is a specific circuit structure diagram of a voltage gating circuit according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of a voltage detection circuit according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] In the description of this invention, terms such as "connection," "linked," "connected," "coupled," and "interconnected," which indicate electrical connection, refer to direct or indirect electrical connections unless otherwise specified. A direct electrical connection refers to a direct connection between two or more objects without any intervening objects, while an indirect electrical connection refers to an electrical connection between two or more objects through the intervening of one or more objects (such as electrical components or units like resistors, capacitors, inductors, switches, and filters).

[0032] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Multi-cell battery protection chips need to detect the voltage of each cell, so the voltage of each cell needs to be introduced into the voltage detection module through a selection switch. Since multiple cells are connected in series, the selection switch needs to be able to withstand high voltage. In related technologies, high-voltage symmetrical MOSFETs with thick gate oxide are usually used to implement the voltage selection circuit. The symmetrical structure ensures that both the drain and source can withstand high voltage. However, many BCD processes only provide LDMOS with thin gate oxide. Therefore, the current approach relies on high-voltage MOSFETs with thick gate oxide, which greatly limits the range of process options. Figure 1The diagram shows an existing gating circuit. The two switches SW1 and SW2 are implemented using thick-gate oxide symmetrical high-voltage PMOS or thick-gate oxide symmetrical high-voltage NMOS. Since the NMOS bulk must be connected to the system's lowest potential VSS and the PMOS bulk must be connected to the system's highest potential VCC, and SW_ON1 and SW_ON2 are logic signals in the VDD_LV low-voltage power domain, they are converted into high-voltage control signals from VSS to VCC by a level shifting module (level_shift) to control the on / off state of switches SW1 and SW2. Therefore, in existing technologies, the two gating switches SW1 and SW2 typically use thick-gate oxide symmetrical high-voltage MOS switches to avoid breakdown by the high-voltage control signals from VSS to VCC.

[0034] To eliminate the dependence of the selection circuit on thick-gate oxide symmetrical high-voltage MOS switches and reduce the risk of the selection circuit being damaged, this embodiment provides a voltage selection circuit for selecting the output voltage of at least one battery cell, with each cell connected in series, such as... Figure 2 As shown, the voltage gating circuit includes: multiple first level conversion circuits (#11~#1n), a second level conversion circuit 2, and multiple gating switch circuits (#31~#3n).

[0035] Figure 2 In this circuit, the input terminal of each first level conversion circuit (#11~#1n) receives one of multiple switch control signals (SW_ON1~SW_ONn), and the input terminal of the second level conversion circuit 2 receives multiple switch control signals (SW_ON1~SW_ONn). The first control terminal of each gating switch circuit (#31~#3n) is connected to the output terminal (i.e., GATEB1~GATEBn terminal) of one of the first level conversion circuits (#11~#1n), and the input terminal of each gating switch circuit (#31~#3n) is connected to the first terminal of one of the first level conversion circuits (#11~#1n), and receives the output voltage (VCELL_1~VCELL_n) of one battery cell. The second control terminal of each gating switch circuit (#31~#3n) is connected to one output terminal (i.e., GATEA1~GATEAn terminal) of the second level conversion circuit 2, and the output terminal of each gating switch circuit (#31~#3n) is connected to the first terminal (i.e., VISO terminal) of the second level conversion circuit 2.

[0036] Specifically, Figure 2In this circuit, the internal structure of each first level conversion circuit (#11~#1n) is identical, and the internal structure of each gating switch circuit (#31~#3n) is identical. VISO is the node connected to the selected potential, and VCELL_1~VCELL_n are the output voltage nodes of the cells to be selected, respectively. At any given time, one of the switch control signals in SW_ON1~SW_ONn has the logic opposite to the other switch control signals. This switch control signal is input to the corresponding first level conversion circuit and second level conversion circuit 2, thereby connecting the output voltage node of a cell to be selected to the VISO node. GATEB1~GATEBn are the control signals for each first level conversion circuit (#11~#1n) to control the on / off state of the corresponding gating switch circuit (#31~#3n) based on the boost or buck conversion of the corresponding switch control signal. GATEA1~GATEAn are the control signals for each second level conversion circuit 2 to control the on / off state of the corresponding gating switch circuit (#31~#3n) based on the boost or buck conversion of the corresponding switch control signal.

[0037] For example, Figure 2 In the process, when it is necessary to select the output voltage VCELL_1 of the first cell, the selection switch circuit #31 needs to be turned on, and the level of the switch control signal SW_ON1 should be opposite to the level of the other switch control signals; when it is necessary to select the output voltage VCELL_2 of the second cell, the selection switch circuit #32 needs to be turned on, and the level of the switch control signal SW_ON2 should be opposite to the level of the other switch control signals, and so on.

[0038] Figure 2 In this circuit, when any selector switch circuit (#31~#3n) needs to be turned on, the first level conversion circuit connected to the selector switch circuit boosts or bucks the input voltage of the selector switch circuit based on the corresponding switch control signal and outputs a first turn-on signal. At the same time, the second level conversion circuit 2 boosts or bucks the output voltage of the selector switch circuit based on the corresponding switch control signal and outputs a second turn-on signal. Then, the selector switch circuit is turned on based on the first turn-on signal and the second turn-on signal, and all other selector switch circuits are turned off.

[0039] For example, Figure 2Taking the output voltage VCELL_1 of the first battery cell as an example, the first selection switch circuit #31 connected to the battery cell needs to be turned on. After setting SW_ON1 to low level and the other switch control signals (SW_ON2~SW_ONn) to high level, the first level conversion circuit #11 boosts the voltage of VCELL_1 and outputs a high level GATEB1. The first output terminal of the second level conversion circuit 2 boosts the voltage of VISO and outputs a high level GATEA1, so that the first selection switch circuit #31 is turned on based on the high level GATEB1 and GATEA1. At this time, the voltage difference between GATEB1 and VCELL_1 does not exceed the breakdown voltage between the first control terminal and the input terminal of the first selection switch circuit #31, and the voltage difference between GATEA1 and VISO does not exceed the breakdown voltage between the output terminal and the second control terminal of the first selection switch circuit #31, thereby avoiding the first selection switch circuit #31 from being broken down by high voltage. Meanwhile, the remaining output terminals of the first level conversion circuit and the second level conversion circuit 2 do not operate under the action of the high-level switch control signal, so that the remaining gating switch circuits remain in the open state.

[0040] It should be noted that the generation methods of the first and second conduction signals are related to the type of switches in the selector circuit. For example, when all switches in the selector circuit are NMOS, the first conduction signal is obtained by boosting the voltage of VCELL_1 and the second conduction signal is obtained by boosting the voltage of VISO. When all switches in the selector circuit are PMOS, the first conduction signal is obtained by deflating the voltage of VCELL_1 and the second conduction signal is obtained by deflating the voltage of VISO.

[0041] Figure 2 In the process, when the arbitrary selection switch circuit (#31~#3n) is turned off, the voltage difference between the first control terminal and the input terminal of the selection switch circuit (#31~#3n), and the voltage difference between the output terminal and the second control terminal of the selection switch circuit (#31~#3n) are both less than the breakdown voltage of the switch in the selection switch circuit (#31~#3n).

[0042] It should be noted that during the circuit design process, by reasonably setting the boost or buck levels of each first level conversion circuit (#11~#1n) and the second level conversion circuit 2, the voltage difference between the control terminal of each selection switch circuit (#31~#3n) and its second control terminal is less than the breakdown voltage.

[0043] The voltage gating circuit provided in this embodiment obtains a first conduction signal by boosting the input voltage of the gating switch circuit, and the voltage between the first conduction signal and the input of the gating switch circuit is less than the breakdown voltage of the switch within the gating switch circuit; the second conduction signal is obtained by boosting the output voltage of the gating switch circuit, and the voltage between the second conduction signal and the output of the gating switch circuit is less than the breakdown voltage of the switch within the gating switch circuit; therefore, neither of the two conduction signals controlling the gating switch circuit will exceed the breakdown voltage drop of the switch within the gating switch circuit, greatly reducing the risk of breakdown. The gating switch circuit does not need to use a thick-gate oxide high-voltage MOS switch to prevent breakdown, reducing the dependence of the voltage gating circuit on thick-gate oxide high-voltage MOS switches and improving the process selection range of circuit design.

[0044] In some alternative implementations, Figure 2 In this circuit, when any selector switch circuit (#31~#3n) needs to be turned off, the first level conversion circuit (#11~#1n) connected to the selector switch circuit (#31~#3n) outputs a first turn-off signal after reducing or increasing the input voltage of the selector switch circuit (#31~#3n) based on the corresponding switch control signal. At the same time, the second level conversion circuit 2 outputs a second turn-off signal after reducing or increasing the output voltage of the selector switch circuit (#31~#3n) based on the corresponding switch control signal of the selector switch circuit. Then, the selector switch circuit (#31~#3n) is turned off based on the first turn-off signal and the second turn-off signal.

[0045] For example, Figure 2 Taking the output voltage VCELL_1 of the first battery cell as an example, the first selection switch circuit #31 connected to the battery cell needs to be turned off. After setting SW_ON1 to high level and the other switch control signals (SW_ON2~SW_ONn) to low level, the first level conversion circuit #11 reduces the voltage of VCELL_1 and outputs a low level GATEB1. The first output terminal of the second level conversion circuit 2 reduces the voltage of VISO and outputs a low level GATEA1, so that the first selection switch circuit #31 is turned off based on the low level GATEB1 and GATEA1. At this time, the voltage difference between GATEB1 and VCELL_1 does not exceed the breakdown voltage between the first control terminal and the input terminal of the first selection switch circuit #31, and the voltage difference between GATEA1 and VISO does not exceed the breakdown voltage between the output terminal and the second control terminal of the first selection switch circuit #31, thereby avoiding the first selection switch circuit #31 from being broken down by high voltage.

[0046] It should be noted that when the switch control signal is at the first logic level, it indicates that the corresponding gating switch circuit needs to be turned on; when the switch control signal is at the second logic level, it indicates that the corresponding gating switch circuit needs to be turned off; the first logic level and the second logic level are opposite.

[0047] It should be noted that the generation methods of the first and second turn-off signals are related to the type of switches in the gating switch circuit. For example, when all switches in the gating switch circuit are NMOS, the first turn-off signal is obtained by stepping down the voltage of VCELL_1 and the second turn-off signal is obtained by stepping down the voltage of VISO. When all switches in the gating switch circuit are PMOS, the first turn-off signal is obtained by stepping up the voltage of VCELL_1 and the second turn-off signal is obtained by stepping up the voltage of VISO.

[0048] In some alternative implementations, such as Figure 3 As shown, taking two gating switch circuits #31 and #32 as examples, each gating switch circuit includes: a first controllable switch (i.e., SW1_MB or SW2_MB) and a second controllable switch (i.e., SW1_MA or SW2_MA).

[0049] Specifically, with Figure 3 Taking the first selection switch circuit #31 as an example, the first terminal of the first controllable switch SW1_MB receives the output voltage VCELL_1 of a battery cell. The second terminal of the first controllable switch SW1_MB is connected to the first terminal of the second controllable switch SW1_MA. The control terminal of the first controllable switch SW1_MB is connected to the output terminal of the first level conversion circuit #11 connected to the battery cell. The second terminal of the second controllable switch SW1_MA is connected to the first terminal of the second level conversion circuit 2. The control terminal of the second controllable switch SW1_MA is connected to the output terminal of the second level conversion circuit 2. One output terminal is connected; the first controllable switch SW1_MB and the second controllable switch SW1_MA are turned on based on the first turn-on signal and the second turn-on signal, respectively; the first controllable switch SW1_MB and the second controllable switch SW1_MA are turned off based on the first turn-off signal and the second turn-off signal, respectively. Since the first controllable switch SW1_MB and the second controllable switch SW1_MA are both NMOS, setting SW_ON1 to a high level and SW_ON2 to a low level is used to control the first controllable switch SW1_MB and the second controllable switch SW1_MA to turn off.

[0050] Specifically, Figure 3 In the process, when the first controllable switch SW1_MB is turned off, the voltage difference between the control terminal and the first terminal of the first controllable switch SW1_MB is less than the breakdown voltage of the first controllable switch SW1_MB; when the second controllable switch SW1_MA is turned off, the voltage difference between the second terminal and the control terminal of the second controllable switch SW1_MA is less than the breakdown voltage of the second controllable switch SW1_MA.

[0051] It should be noted that the number of the first and second controllable switches can be set as needed and connected in series.

[0052] In some alternative implementations, such as Figure 4 As shown, taking the second first level conversion circuit #12 as an example, the second first level conversion circuit #12 includes: a first voltage regulation unit 11, a second voltage regulation unit 12 and a first output unit 13.

[0053] Figure 4 In the first voltage regulating unit 11, the input terminal is connected to the input terminal of the second voltage regulating unit 12 and the input terminal of the corresponding gating switch circuit #32. The output terminal of the first voltage regulating unit 11 is connected to the first input terminal of the first output unit 13. The first voltage regulating unit 11 is used to boost the input voltage VCELL_2 of the gating switch circuit #32 and output the first reference voltage VCELL2_H.

[0054] Figure 4 In the first voltage regulating unit 11, there are: a first current source ibiasB5, a first voltage regulating unit, and a first voltage follower unit. The first voltage regulating unit is composed of four PMOS transistors (MPB0, MPB1, MPB2, and MPB3) connected in series. The first voltage follower unit is composed of a source follower MNSFB. The first terminal of the first voltage regulating unit is connected to the first terminal of the first voltage follower unit and the first terminal of the first current source ibiasB5. The second terminal of the first voltage regulating unit is connected to the input terminal of a gating switch circuit #32. The second terminal of the first voltage follower unit is connected to the second terminal of the first current source ibiasB5. The third terminal of the first voltage follower unit is connected to the first input terminal of the first output unit 13 and outputs the first reference voltage VCELL2_H.

[0055] Specifically, Figure 4 In this circuit, the first reference voltage VCELL2_H is equal to the sum of the voltage drop of the first regulator unit and the input voltage VCELL_2 of the gating switch circuit #32. That is, the potential of the first reference voltage VCELL2_H is equal to the voltage drop generated by the pull-up current of the first current source ibiasB5 flowing through the four series-connected PMOS transistors, plus the potential of VCELL_2, minus the voltage drop of the voltage follower MNSFB. By adjusting the size of the PMOS transistors, the number of them in series, or changing the circuit connections, the voltage difference between VCELL2_H and VCELL_2 is adjusted using the body effect, ensuring that this voltage difference is lower than the gate oxide breakdown voltage of SW2_MB in the gating switch circuit #32. The source follower MNSFB has a very low output resistance, which can provide a large current to drive the load while maintaining the stability of the output signal. It can be used to provide driving capability for its voltage output node.

[0056] Optionally, the first voltage regulator unit is used to boost VCELL_2 and output the first reference voltage VCELL2_H. Its structure can be formed by multiple NMOS and PMOS cascaded together, or by using the voltage drop of the resistor, or by using the voltage drop of the PN junction. Its specific structure is not limited here.

[0057] Figure 4 In the first output unit 13, the output terminal (i.e., VCELL2_L) and the first terminal (i.e., VSS) of the second voltage regulating unit 12 are respectively connected to the second input terminal and the first terminal of the first output unit 13. The second voltage regulating unit 12 is used to step down the input voltage VCELL_2 of the gating switch circuit #32 and output the second reference voltage VCELL2_L.

[0058] Figure 4 In the second voltage regulating unit 12, there are: a second current source ibiasB1 and a second voltage regulating unit, wherein the second voltage regulating unit is composed of three NMOS transistors MNB1, MNB2, and MNB3 connected in series. The first terminal of the second voltage regulating unit is connected to the input terminal of a gating switch circuit #32, and the second terminal of the second voltage regulating unit is connected to the first terminal of the second current source ibiasB1 and the second input terminal of the first output unit 13 and outputs a second reference voltage VCELL2_L; the second terminal of the second current source ibiasB1 is connected to the first terminal (i.e., VSS) of the first output unit 13.

[0059] Specifically, Figure 4 In this circuit, the second reference voltage VCELL2_L is equal to the difference between the input voltage of the gating switch circuit (#31~#3n) and the voltage drop of the second voltage regulator unit itself. That is, the potential of the second reference voltage VCELL2_L is equal to the potential of VCELL_2 minus the voltage drop generated by the pull-down current of the second current source ibiasB1 flowing through the three series-connected NMOS transistors. By adjusting the size of the NMOS transistors, the number of NMOS transistors connected in series, or changing the circuit connections, the voltage difference between VCELL_2 and VCELL2_L can be adjusted using the body effect, ensuring that this voltage difference is lower than the gate oxide breakdown voltage of SW2_MB in the gating switch circuit #32.

[0060] Figure 4 In this circuit, the output terminal (GATEB2) of the first output unit 13 is connected to the first control terminal of a corresponding gating switch circuit #32. The control terminal of the first output unit 13 is connected to the corresponding switch control signal. The first output unit 13 is used to output a first turn-on signal (i.e., GATEB2 is high level) based on the corresponding switch control signal and the first reference voltage VCELL2_H, or to output a first turn-off signal (i.e., GATEB2 is low level) based on the corresponding switch control signal and the second reference voltage VCELL2_L.

[0061] Figure 4In the first output unit 13, there are: a first output driving unit 131 and a second output driving unit 132. The first end of the first output driving unit 131 is connected to the output end (i.e., VCELL2_H) of the first voltage regulating unit 11. The second end of the first output driving unit 131 is connected to the first end of the second output driving unit 132 and the first control end of a corresponding gating switch circuit #32. The second end (i.e., VCELL2_L) and the third end (i.e., VSS) of the second output driving unit 132 are respectively connected to the output end and the first end of the second voltage regulating unit 12. The fourth end of the second output driving unit 132 is connected to the corresponding switch control signal.

[0062] Specifically, Figure 4 In this configuration, the first output driving unit 131 includes a common-source, common-gate current mirror composed of MPB4 and MPB5. MPB5 and MPB4 have the same size, therefore the VGS and VDS of the two PMOS transistors are the same. The second output driving unit 132 includes two NMOS transistors: MNB4 and MNB5. The first output driving unit 131 is used to convert the first reference voltage VCELL2_H into a first turn-on signal (i.e., GATEB2 is high) based on the corresponding switch control signal. The second output driving unit 132 is used to convert the second reference voltage VCELL2_L into a first turn-off signal (i.e., GATEB2 is low) based on the corresponding switch control signal. When the switch control signal is at a first logic level, the first output driving unit 131 converts the first reference voltage into a first turn-on signal; when the switch control signal is at a second logic level, the second output driving unit 132 converts the second reference voltage into a first turn-off signal.

[0063] For example, Figure 4 Taking the output voltage VCELL_2 of the second battery cell as an example, which needs to be selected, the corresponding second selection switch circuit #32 connected to the battery cell needs to be turned on. When SW2_MB needs to be turned on, after setting SW_ON1 to high level and SW_ON2 to low level, MNB4 is turned off based on the low level SW_ON2. After the drain potential of the current mirror MPB5 is pulled up to the source potential VCELL2_H, GATEB2 becomes high level to drive SW2_MB to turn on. At this time, the voltage difference between GATEB2 and VCELL_2 is lower than the gate oxide breakdown voltage of SW2_MB in the selection switch circuit #32.

[0064] For example, Figure 4Taking the output voltage VCELL_2 of the second battery cell as an example, which needs to be selected, the corresponding second selection switch circuit #32 connected to the battery cell needs to be turned off. When SW2_MB needs to be turned off, after setting SW_ON1 to low level and SW_ON2 to high level, MNB4 is turned on based on the high level SW_ON2. Since the current pull-down capability of the current source ibiasB3 is greater than the pull-up capability of MPB5 in the current mirror, the drain voltage of MNB4 will be continuously pulled down. Due to the clamping effect of MNB5, the lower limit of this voltage pull-down will not exceed the on-state voltage drop of MNB5. That is, the drain voltage of MNB4 is pulled down to the second reference voltage VCELL2_L minus the VGS of MNB5, so that SW2_MB is turned off after GATEB2 becomes low level. At this time, the voltage difference between VCELL_2 and GATEB2 is lower than the gate oxide breakdown voltage of SW2_MB in the selection switch circuit #32.

[0065] It should be noted that the clamping function of MNB5 can also be achieved by other PMOS transistors or by diodes.

[0066] It should be noted that this embodiment is illustrated using the case where all switches in the selector switch circuit are NMOS. When all switches in the selector switch circuit are PMOS, those skilled in the art can set the boost and buck processes of the first voltage regulating unit and the second voltage regulating unit according to the actual circuit logic requirements, and adapt to changing the magnitude of the first reference voltage and the second reference voltage.

[0067] In some alternative implementations, such as Figure 4 As shown, the second level conversion circuit 2 includes: a third voltage regulation unit 21, a fourth voltage regulation unit 22, and a second output unit 23.

[0068] Figure 4 In the middle, the input terminal of the third voltage regulating unit 21 is connected to the input terminal of the fourth voltage regulating unit 22 and the output terminal (i.e., VISO) of each gating switch circuit. The output terminal (i.e., VISO_H) of the third voltage regulating unit 21 is connected to the first input terminal of the second output unit 23. The third voltage regulating unit 21 is used to boost the output voltage VISO of the gating switch circuit (#31~#3n) and output the third reference voltage VISO_H.

[0069] Figure 4In the third voltage regulating unit 21, there are: a third current source ibiasA5, a fifth voltage regulating unit, and a second voltage follower unit. The third voltage regulating unit is composed of four PMOS transistors (MPA0, MPA1, MPA2, and MPA3) connected in series. The second voltage follower unit is composed of a source follower MNSFA. The first terminal of the third voltage regulating unit is connected to the first terminal of the second voltage follower unit and the first terminal of the third current source ibiasA5. The second terminal of the third voltage regulating unit is connected to the output terminal of each selection switch circuit. The second terminal of the second voltage follower unit is connected to the second terminal of the third current source ibiasA5. The third terminal of the second voltage follower unit is connected to the first input terminal of the second output unit 23 and outputs the third reference voltage VISO_H.

[0070] Specifically, Figure 4 Taking the second gating switch circuit #32 as an example, the third reference voltage VISO_H is equal to the sum of the voltage drop of the third voltage regulator unit and the output voltage VISO of the gating switch circuit. That is, the potential of the third reference voltage VISO_H is equal to the voltage drop generated by the pull-up current of the third current source ibiasA5 flowing through the four series-connected PMOS transistors, plus the potential of VISO, minus the voltage drop of the voltage follower MNSFA. By adjusting the size of the PMOS transistors, the number of them in series, or changing the circuit connections, the voltage difference between VISO_H and VISO can be adjusted using the body effect, ensuring that this voltage difference is lower than the gate oxide breakdown voltage SW2_MA in the gating switch circuit #32. The source follower MNSFA has a very low output resistance, which can provide a large current to drive the load while maintaining the stability of the output signal. It can be used to provide driving capability for its voltage output node.

[0071] Optionally, the third voltage regulator unit is used to boost VISO and output a third reference voltage VISO_H. Its structure can be formed by multiple NMOS and PMOS cascaded together, or by using the voltage drop of a resistor, or by using the voltage drop of a PN junction. Its specific structure is not limited here.

[0072] Figure 4 In the middle, the output terminal (i.e., VISO_L) and the first terminal (i.e., VSS) of the fourth voltage regulating unit 22 are respectively connected to the second input terminal and the first terminal of the second output unit 23. The fourth voltage regulating unit 22 is used to reduce the output voltage VISO of the gating switch circuit (#31~#3n) and output the fourth reference voltage VISO_L.

[0073] Figure 4In the fourth voltage regulating unit 22, there are: a fourth current source ibiasA1 and a fourth voltage regulating unit, wherein the fourth voltage regulating unit is composed of three NMOS transistors MNA1, MNA2, and MNA3 connected in series. The first terminal of the fourth voltage regulating unit is connected to the output terminal (i.e., VISO) of each gating switch circuit #32, and the second terminal of the fourth voltage regulating unit is connected to the first terminal of the fourth current source ibiasA1 and the second input terminal of the second output unit 23 and outputs the fourth reference voltage VISO_L; the second terminal of the fourth current source ibiasA1 is connected to the first terminal (i.e., VSS) of the second output unit 23.

[0074] Specifically, Figure 4 In this circuit, the fourth reference voltage VISO_L is equal to the difference between the output voltage VISO of the gating switch circuit and the voltage drop of the fourth voltage regulator unit itself. That is, the potential of the fourth reference voltage VISO_L is equal to the potential of VISO minus the voltage drop generated by the pull-down current of the fourth current source ibiasA1 flowing through the three series-connected NMOS transistors. By adjusting the size of the NMOS transistors, the number of NMOS transistors connected in series, or changing the circuit connections, the voltage difference between VISO and VISO_L can be adjusted using the body effect, ensuring that this voltage difference is lower than the gate oxide breakdown voltage SW2_MB in the gating switch circuit #32.

[0075] Figure 4 In this circuit, one of the multiple input terminals of the second output unit 23 (i.e., the gate of MNA4 or the gate of MNA6) is input to one of the multiple switch control signals. One of the multiple output terminals of the second output unit 23 (i.e., GATEA1 or GATEA2) is connected to the second control terminal of a corresponding gating switch circuit #32. The second output unit 23 is used to output the second turn-on signal of the corresponding gating switch circuit (i.e., GATEA1 or GATEA2 is high level) based on the corresponding switch control signal (SW_ON1 or SW_ON2) and the third reference voltage VISO_H, or to output the second turn-off signal of the corresponding gating switch circuit (i.e., GATEA1 or GATEA2 is low level) based on the corresponding switch control signal and the fourth reference voltage VISO_L.

[0076] Figure 4In this embodiment, the second output unit 23 includes multiple output drive branches (231 to 23n) connected in parallel. In this embodiment, 23 is described as including two output drive branches 231 and 232. Each output drive branch includes an output terminal. The output terminal of each output drive branch is connected to the second control terminal of a corresponding gating switch circuit. The control terminal of each output drive branch is connected to a corresponding switch control signal. The first terminal of each output drive branch is connected to the output terminal of the third voltage regulating unit and receives the third reference voltage VISO_H. The second terminal of each output drive branch is connected to the output terminal of the fourth voltage regulating unit and receives the fourth reference voltage VISO_L.

[0077] Specifically, Figure 4 In this circuit, each output drive branch outputs a second turn-on signal for the corresponding gating switch circuit based on a corresponding switch control signal and a third reference voltage, or outputs a second turn-off signal for the corresponding gating switch circuit based on a corresponding switch control signal and a fourth reference voltage.

[0078] Specifically, Figure 4 In this configuration, each output drive branch includes a third output drive unit and a fourth output drive unit. Taking output drive branch 231 as an example, the third output drive unit includes switch MPA5, and the fourth output drive unit includes switches MNA4 and MNA5. Taking output drive branch 232 as an example, the third output drive unit includes switch MPA6, and the fourth output drive unit includes switches MNA6 and MNA7. The control terminals of switches MPA5 and MPA6 are both connected to the control terminal of switch MPA4 and form current mirrors with switch MPA4 respectively.

[0079] Specifically, Figure 4 Taking the output drive branch 231 as an example, the first end of the third output drive unit is connected to the output end of the third voltage regulating unit 21 and receives the third reference voltage VISO_H. The second end of the third output drive unit is connected to the first end of the fourth output drive unit and the second control end of a corresponding gating switch circuit. The third output drive unit is used to convert the third reference voltage VISO_H into a second conduction signal based on the corresponding switch control signal.

[0080] Specifically, Figure 4Taking the output drive branch 231 as an example, the second terminal of the fourth output drive unit is connected to the output terminal of the fourth voltage regulation unit 22, and the third terminal of the fourth output drive unit is connected to a corresponding switch control signal (i.e., SW_ON2). The fourth output drive unit is used to convert the fourth reference voltage VISO_L into a second turn-off signal based on the corresponding switch control signal. When the switch control signal is at the first logic level, the third output drive unit converts the third reference voltage VISO_H into a second turn-on signal. When the switch control signal is at the second logic level, the fourth output drive unit converts the fourth reference voltage VISO_L into a second turn-off signal.

[0081] For example, Figure 4 Taking the output voltage VCELL_2 of the second battery cell as an example, which needs to be selected, the corresponding second selection switch circuit #32 connected to the battery cell needs to be turned on. When SW2_MA needs to be turned on, after setting SW_ON1 to high level and SW_ON2 to low level, MNA4 is turned off based on the low level of SW_ON2. After the drain potential of the current mirror MPA5 is pulled up to the source potential VISO_H, GATEA2 becomes high level to drive SW2_MA to turn on. At this time, the voltage difference between GATEA2 and VISO is lower than the gate oxide breakdown voltage of SW2_MA in the selection switch circuit #32.

[0082] For example, Figure 4 Taking the output voltage VCELL_2 of the second battery cell as an example, which needs to be selected, the corresponding second selection switch circuit #32 connected to the battery cell needs to be turned off. When SW2_MA needs to be turned off, after setting SW_ON1 to low level and SW_ON2 to high level, MNA4 is turned on based on the high level SW_ON2. Since the current pull-down capability of the current source ibiasA3 is set to be greater than the pull-up capability of MPA5 in the current mirror, the drain voltage of MNA4 will be continuously pulled down. Due to the clamping effect of MNA5, the lower limit of this voltage pull-down will not exceed the on-state voltage drop of MNA5. That is, the drain voltage of MNA4 is pulled down to the fourth reference voltage VISO_L minus the VGS of MNA5, so that SW2_MA is turned off after GATEA2 becomes low level. At this time, the voltage difference between VISO and GATEA2 is lower than the gate oxide breakdown voltage of SW2_MA in the selection switch circuit #32.

[0083] It should be noted that the clamping function of MNA5 can also be achieved by connecting MNA7, or by other PMOS transistors, or by a diode.

[0084] It should be noted that, provided that the level logic of the switch control signal corresponding to the selector switch circuit that needs to be turned on is opposite to the level logic of the switch control signal corresponding to the other selector switch circuits, those skilled in the art can set the level logic of the switch control signal according to actual needs.

[0085] This embodiment provides a voltage detection circuit, such as Figure 5 As shown, the system includes: a control module, a voltage detection module, and a voltage gating circuit according to the above embodiments or any corresponding implementation. The output terminal of the control module is connected to the input terminal of each first level conversion circuit (#11~#1n) and the input terminal of the second level conversion circuit 2. The control module is used to output multiple switch control signals. The input terminal of the voltage detection module is connected to the output terminal of each gating switch circuit (#31~#3n). The voltage detection module is used to detect the input voltage. When it is necessary to detect the output voltage of any cell, the first level conversion circuit (#11~#1n) connected to the cell outputs a first conduction signal based on the corresponding switch control signal, and the second level conversion circuit 2 outputs a second conduction signal. Then, the gating switch circuit (#31~#3n) connected to the cell is turned on and outputs the output voltage of the cell.

[0086] It should be noted that the selection or disabling method of the voltage gating circuit in this embodiment is the same as that in the above embodiments and any corresponding implementation methods, and will not be repeated here.

[0087] The voltage detection circuit provided in this embodiment obtains a first conduction signal by boosting the input voltage of the gating switch circuit, and the voltage between the first conduction signal and the input voltage of the gating switch circuit is less than the breakdown voltage of the switch within the gating switch circuit; the second conduction signal is obtained by boosting the output voltage of the gating switch circuit, and the voltage between the second conduction signal and the output voltage of the gating switch circuit is less than the breakdown voltage of the switch within the gating switch circuit; when the output voltage of multiple cells is detected simultaneously, regardless of the total output voltage, the two conduction signals controlling the gating switch circuit will not exceed the breakdown voltage drop of the switch within the gating switch circuit, greatly reducing the risk of breakdown. The gating switch circuit does not need to use a thick-gate oxide high-voltage MOS switch to prevent breakdown, reducing the dependence of the voltage gating circuit on thick-gate oxide high-voltage MOS switches and improving the process selection range of circuit design.

[0088] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A voltage gating circuit, characterized in that, The voltage selection circuit is used to select the output voltage of at least one battery cell. The voltage selection circuit includes: multiple first level conversion circuits, a second level conversion circuit, and multiple selection switch circuits, wherein... Each of the first level conversion circuits receives one of a plurality of switch control signals at its input terminal, and the second level conversion circuit receives the plurality of switch control signals at its input terminal. The first control terminal of each of the gating switch circuits is connected to the output terminal of one of the first level conversion circuits, and the input terminal of each of the gating switch circuits is connected to the first terminal of one of the first level conversion circuits and receives the output voltage of one battery cell; the second control terminal of each of the gating switch circuits is connected to a corresponding output terminal of the second level conversion circuit, and the output terminal of each of the gating switch circuits is connected to the first terminal of the second level conversion circuit. When any of the selected switch circuits needs to be turned on, the first level conversion circuit connected to the selected switch circuit boosts or bucks the input voltage of the selected switch circuit based on the corresponding switch control signal and outputs a first turn-on signal. At the same time, the second level conversion circuit boosts or bucks the output voltage of the selected switch circuit based on the corresponding switch control signal and outputs a second turn-on signal. Then the selected switch circuit is turned on based on the first turn-on signal and the second turn-on signal. At this time, all other selected switch circuits are turned off. When any of the selected switch circuits is turned off, the voltage difference between the first control terminal and its input terminal of the selected switch circuit, and the voltage difference between the output terminal and its second control terminal of the selected switch circuit, are both less than the breakdown voltage of the switch in the selected switch circuit.

2. The voltage gating circuit according to claim 1, characterized in that, When any of the selected switch circuits needs to be turned off, the first level conversion circuit connected to the selected switch circuit outputs a first turn-off signal after the input voltage of the selected switch circuit is reduced or increased based on the corresponding switch control signal. At the same time, the second level conversion circuit outputs a second turn-off signal after the output voltage of the selected switch circuit is reduced or increased based on the corresponding switch control signal of the selected switch circuit. Then the selected switch circuit is turned off based on the first turn-off signal and the second turn-off signal. When the switch control signal is at the first logic level, it indicates that the corresponding gating switch circuit needs to be turned on. When the switch control signal is at the second logic level, it indicates that the corresponding gating switch circuit needs to be disconnected. The first logic level is the opposite of the second logic level.

3. The voltage gating circuit according to claim 2, characterized in that, Each of the aforementioned gating switch circuits includes: a first controllable switch and a second controllable switch, wherein... The first terminal of the first controllable switch receives the output voltage of a battery cell, the second terminal of the first controllable switch is connected to the first terminal of the second controllable switch, and the control terminal of the first controllable switch is connected to the output terminal of the first level conversion circuit connected to the battery cell. The second terminal of the second controllable switch is connected to the first terminal of the second level conversion circuit, and the control terminal of the second controllable switch is connected to one output terminal of the second level conversion circuit. The first controllable switch and the second controllable switch are turned on based on the first conduction signal and the second conduction signal, respectively; The first controllable switch and the second controllable switch are turned off based on the first turn-off signal and the second turn-off signal, respectively; When the first controllable switch is turned off, the voltage difference between the control terminal and the first terminal of the first controllable switch is less than the breakdown voltage of the first controllable switch. When the second controllable switch is turned off, the voltage difference between the second terminal of the second controllable switch and its control terminal is less than the breakdown voltage of the second controllable switch.

4. The voltage gating circuit according to claim 2, characterized in that, Each of the first level conversion circuits includes: a first voltage regulation unit, a second voltage regulation unit, and a first output unit, wherein... The input terminal of the first voltage regulating unit is connected to the input terminal of the second voltage regulating unit and the input terminal of a corresponding gating switch circuit. The output terminal of the first voltage regulating unit is connected to the first input terminal of the first output unit. The first voltage regulating unit is used to boost the input voltage of the gating switch circuit and output a first reference voltage. The output terminal and the first terminal of the second voltage regulating unit are respectively connected to the second input terminal and the first terminal of the first output unit. The second voltage regulating unit is used to reduce the input voltage of the gating switch circuit and output the second reference voltage. The output terminal of the first output unit is connected to the first control terminal of a corresponding gating switch circuit. The control terminal of the first output unit is connected to the corresponding switch control signal. The first output unit is used to output a first turn-on signal based on the corresponding switch control signal and the first reference voltage, or to output a first turn-off signal based on the corresponding switch control signal and the second reference voltage.

5. The voltage gating circuit according to claim 4, characterized in that, The first voltage regulating unit includes: a first current source, a first voltage regulating unit, and a first voltage follower unit, wherein, The first terminal of the first voltage regulator unit is connected to the first terminal of the first voltage follower unit and the first terminal of the first current source and outputs the first reference voltage. The second terminal of the first voltage regulator unit is connected to the input terminal of a gating switch circuit. The magnitude of the first reference voltage is adjusted by adjusting the parameters of the voltage regulator device in the first voltage regulator unit. The second terminal of the first voltage follower unit is connected to the second terminal of the first current source, and the third terminal of the first voltage follower unit is connected to the first input terminal of the first output unit. The first voltage follower unit is used to improve the driving capability of the first reference voltage. The first reference voltage is equal to the sum of the voltage drop of the first voltage regulator unit and the input voltage of the gating switch circuit.

6. The voltage gating circuit according to claim 5, characterized in that, The second voltage regulating unit includes: a second current source and a second voltage regulating unit, wherein, The first terminal of the second voltage regulator unit is connected to the input terminal of one of the gating switch circuits, and the second terminal of the second voltage regulator unit is connected to the first terminal of the second current source and the second input terminal of the first output unit and outputs the second reference voltage. The magnitude of the second reference voltage is adjusted by adjusting the parameters of the voltage regulator device in the second voltage regulator unit. The second terminal of the second current source is connected to the first terminal of the first output unit; The second reference voltage is equal to the difference between the input voltage of the gating switch circuit and the voltage drop of the second voltage regulator unit itself.

7. The voltage gating circuit according to claim 4 or 6, characterized in that, The first output unit includes: a first output driving unit and a second output driving unit, wherein, The first terminal of the first output driving unit is connected to the output terminal of the first voltage regulating unit, and the second terminal of the first output driving unit is connected to the first terminal of the second output driving unit and the first control terminal of a corresponding gating switch circuit. The first output driving unit is used to convert the first reference voltage into a first conduction signal based on the corresponding switch control signal. The second and third terminals of the second output driving unit are respectively connected to the output terminal and the first terminal of the second voltage regulating unit. The fourth terminal of the second output driving unit is connected to the corresponding switch control signal. The second output driving unit is used to convert the second reference voltage into a first turn-off signal based on the corresponding switch control signal. When the switch control signal is at the first logic level, the first output drive unit converts the first reference voltage into a first conduction signal; When the switch control signal is at the second logic level, the second output drive unit converts the second reference voltage into a first turn-off signal.

8. The voltage gating circuit according to claim 2, characterized in that, The second level conversion circuit includes: a third voltage regulation unit, a fourth voltage regulation unit, and a second output unit, wherein, The input terminal of the third voltage regulating unit is connected to the input terminal of the fourth voltage regulating unit and the output terminal of each of the gating switch circuits. The output terminal of the third voltage regulating unit is connected to the first input terminal of the second output unit. The third voltage regulating unit is used to boost the output voltage of the gating switch circuit and output a third reference voltage. The output terminal and the first terminal of the fourth voltage regulating unit are respectively connected to the second input terminal and the first terminal of the second output unit. The fourth voltage regulating unit is used to reduce the output voltage of the gating switch circuit and output a fourth reference voltage. One of the plurality of input terminals of the second output unit is input to one of the plurality of switch control signals, and one of the plurality of output terminals of the second output unit is connected to the second control terminal of a corresponding gating switch circuit. The second output unit is used to output a second turn-on signal corresponding to the gating switch circuit based on the corresponding switch control signal and the third reference voltage, or to output a second turn-off signal corresponding to the gating switch circuit based on the corresponding switch control signal and the fourth reference voltage.

9. The voltage gating circuit according to claim 8, characterized in that, The third voltage regulating unit includes: a third current source, a third voltage regulating unit, and a second voltage follower unit, wherein... The first terminal of the third voltage regulator unit is connected to the first terminal of the second voltage follower unit and the first terminal of the third current source and outputs the third reference voltage. The second terminal of the third voltage regulator unit is connected to the output terminal of each of the gating switch circuits. The magnitude of the third reference voltage is adjusted by adjusting the parameters of the voltage regulator device in the third voltage regulator unit. The second terminal of the second voltage follower unit is connected to the second terminal of the third current source, and the third terminal of the second voltage follower unit is connected to the first input terminal of the second output unit. The second voltage follower unit is used to improve the driving capability of the third reference voltage. The third reference voltage is equal to the sum of the voltage drop of the third voltage regulator unit and the output voltage of the gating switch circuit.

10. The voltage gating circuit according to claim 9, characterized in that, The fourth voltage regulating unit includes: a fourth current source and a fourth voltage stabilizing unit, wherein... The first terminal of the fourth voltage regulator unit is connected to the output terminal of one of the gating switch circuits. The second terminal of the fourth voltage regulator unit is connected to the first terminal of the fourth current source and the second input terminal of the second output unit and outputs the fourth reference voltage. The magnitude of the fourth reference voltage is adjusted by adjusting the parameters of the voltage regulator device in the fourth voltage regulator unit. The second terminal of the fourth current source is connected to the first terminal of the second output unit; The fourth reference voltage is equal to the difference between the output voltage of the gating switch circuit and the voltage drop of the fourth voltage regulator unit itself.

11. The voltage gating circuit according to claim 8 or 10, characterized in that, The second output unit includes: multiple output drive branches, wherein, Each output drive branch includes an output terminal. The output terminal of each output drive branch is connected to the second control terminal of a corresponding gating switch circuit. The control terminal of each output drive branch is connected to a corresponding switch control signal. The first terminal of each output drive branch is connected to the output terminal of the third voltage regulating unit and receives a third reference voltage. The second terminal of each output drive branch is connected to the output terminal of the fourth voltage regulating unit and receives a fourth reference voltage. Each output drive branch outputs a second turn-on signal corresponding to the gating switch circuit based on a corresponding switch control signal and the third reference voltage, or outputs a second turn-off signal corresponding to the gating switch circuit based on a corresponding switch control signal and the fourth reference voltage. Each output drive branch includes a third output drive unit and a fourth output drive unit, wherein... The first terminal of the third output driving unit is connected to the output terminal of the third voltage regulating unit and receives the third reference voltage. The second terminal of the third output driving unit is connected to the first terminal of the fourth output driving unit and the second control terminal of a corresponding gating switch circuit. The third output driving unit is used to convert the third reference voltage into a second conduction signal based on the corresponding switch control signal. The second end of the fourth output driving unit is connected to the output end of the fourth voltage regulating unit, and the third end of the fourth output driving unit is connected to a corresponding switch control signal. The fourth output driving unit is used to convert the fourth reference voltage into a second turn-off signal based on the corresponding switch control signal. When the switch control signal is at the first logic level, the third output drive unit converts the third reference voltage into a second conduction signal; When the switch control signal is at the second logic level, the fourth output drive unit converts the fourth reference voltage into a second turn-off signal.

12. A voltage detection circuit, characterized in that, include: The control module, the voltage detection module, and the voltage gating circuit according to any one of claims 1 to 11, wherein, The output terminal of the control module is connected to the input terminal of each first level conversion circuit and the input terminal of each second level conversion circuit. The control module is used to output multiple switch control signals. The input terminal of the voltage detection module is connected to the output terminal of each gating switch circuit, and the voltage detection module is used to detect the input voltage. When it is necessary to detect the output voltage of any battery cell, the first level conversion circuit connected to the battery cell outputs a first conduction signal based on the corresponding switch control signal, and the second level conversion circuit outputs a second conduction signal. Then, the gating switch circuit connected to the battery cell is turned on and outputs the output voltage of the battery cell.

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