A broken line detection circuit and chip

Abstract

The embodiment of the application discloses a disconnection detection circuit and a chip, wherein a plurality of batteries are connected in parallel with a plurality of resistors one by one; a first end of a first voltage dividing resistor is connected with a first connection end formed by two resistors; a first end of a second voltage dividing resistor is connected with a second connection end formed by the other two resistors, and one or more resistors exist between the first connection end and the second connection end; a first current source is connected between a second end of the first voltage dividing resistor and a first reference voltage end; a second current source is connected between a second end of the second voltage dividing resistor and the first reference voltage end; two input ends of a comparison module are connected with the second end of the first voltage dividing resistor and the second end of the second voltage dividing resistor respectively, and an output end of the comparison module outputs a signal for representing a disconnection detection result. Through the ingenious design of the connection relationship of each element, whether a disconnection phenomenon exists between two batteries and the disconnection detection circuit can be detected by using one comparison module, the circuit is simplified, and power consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and specifically to a wire breakage detection circuit and chip. Background Technology

[0002] Currently, for the charging and discharging process of multiple series-connected batteries, a dedicated detection circuit is typically required to detect any abnormalities. If a break in the connection between the battery and the detection circuit occurs, the detection results will deviate from the actual situation, hindering the control of the battery's charging and discharging process. To avoid this, existing technologies include dedicated break-circuit protection circuits, such as... Figure 1 One existing open circuit protection structure involves setting a current source between each adjacent battery. By pulling up or pulling down the current source, an abnormal voltage is caused at the detection point, thereby determining whether an open circuit has occurred. However, this type of open circuit protection requires a large current source; otherwise, when the battery voltage is low, abnormal open circuit detection results are likely to occur, placing high demands on circuit design. Summary of the Invention

[0003] The purpose of this invention is to provide a disconnection detection circuit and chip to solve the above-mentioned problems. This invention achieves the above objective through the following technical solutions.

[0004] This invention provides a disconnection detection circuit for use with multiple batteries connected in series. The disconnection detection circuit includes: multiple resistors connected in series, with each battery connected in parallel with one of the resistors; a first voltage divider resistor, the first end of which is connected to a first connection terminal formed by two resistors; a second voltage divider resistor, the first end of which is connected to a second connection terminal formed by two other resistors, with one or more resistors existing between the first connection terminal and the second connection terminal; a first current source connected between the second end of the first voltage divider resistor and a first reference voltage terminal; a second current source connected between the second end of the second voltage divider resistor and the first reference voltage terminal; and a comparison module, the first input terminal of which is connected to the second end of the first voltage divider resistor, the second input terminal of which is connected to the second end of the second voltage divider resistor, and the output terminal of which outputs a signal characterizing the disconnection detection result.

[0005] This invention also provides a wire breakage detection chip, which includes the wire breakage detection circuit provided in the above embodiments.

[0006] Compared to existing technologies, the open circuit and chip provided in this embodiment are applied to multiple batteries connected in series. The open circuit includes multiple resistors connected in series, a first voltage divider resistor, a second voltage divider resistor, a first current source, a second current source, and a comparison module. The multiple batteries are connected in parallel with the multiple resistors one by one. The first end of the first voltage divider resistor is connected to a first connection terminal formed by two resistors. The first end of the second voltage divider resistor is connected to a second connection terminal formed by two other resistors. One or more resistors exist between the first and second connection terminals. The first current source is connected between the second end of the first voltage divider resistor and a first reference voltage terminal. The second current source is connected between the second end of the second voltage divider resistor and the first reference voltage terminal. The first input terminal of the comparison module is connected to the second end of the first voltage divider resistor, and the second input terminal of the comparison module is connected to the second end of the second voltage divider resistor. Its output terminal outputs a signal characterizing the open circuit detection result. By cleverly designing the connection relationships between the resistor connected in parallel with the battery and the first voltage divider resistor R1, the second voltage divider resistor R2, the first current source, and the second current source, a single comparison module can detect whether there is a break in the connection between the two batteries and the break detection circuit. This simplifies the circuit and reduces power consumption. At the same time, this comparison module can use a common comparator without mismatch, reducing design difficulty. Attached Figure Description

[0007] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram of a conventional interruption detection circuit.

[0009] Figure 2 This is another structural schematic diagram of an existing interrupted line detection circuit.

[0010] Figure 3 This is a schematic diagram of a module of the wire breakage detection circuit provided in an embodiment of the present invention.

[0011] Figure 4 This is a schematic diagram of another module of the wire breakage detection circuit provided in an embodiment of the present invention.

[0012] Figure 5 This is a schematic diagram of a broken wire detection circuit provided in an embodiment of the present invention.

[0013] Figure 6 This is a schematic diagram of the reference current generation module in the open circuit detection circuit provided in this embodiment of the invention.

[0014] Figure 7 This is another structural schematic diagram of the wire breakage detection circuit provided in the embodiment of the present invention.

[0015] Figure 8 This is a schematic diagram of an application of the wire breakage detection circuit provided in an embodiment of the present invention. Detailed Implementation

[0016] 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, not all, of the embodiments of the present invention. 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.

[0017] To better understand the technical solutions of the embodiments of the present invention, the prior art described in the background section will be further elaborated below. Figure 1 In the illustrated technical solution, if it is necessary to detect whether there is a break in the connection between the positive terminal of the Nth battery and the detection circuit, a voltage divider resistor and a current source are connected to the detection terminal of the detection circuit connected to the positive terminal of the Nth battery. When the connection is broken at V4, the inverter inv flips due to the pull-down effect of the current source IB3. If the pull-down strength of the current source IB3 is low, the preset flipping condition cannot be achieved. Furthermore, since the current source IB3 also involves the flipping of the overcharge comparator and over-discharge comparator, the current of the current source IB3 needs to be large, resulting in high power consumption and demanding circuit design requirements. Additionally... Figure 1 The technical solution shown is for detecting the disconnection of the Nth battery. If it is necessary to detect whether there is a disconnection between the battery and other batteries, the corresponding detection circuit needs to be set up repeatedly. Otherwise, it is impossible to detect the connection status with multiple batteries.

[0018] Figure 2 The illustrated technical solution is another type of open-circuit protection circuit in the prior art. It mainly uses parallel current sources for odd-numbered batteries. Based on the characteristic that the current source decreases when a circuit is broken, it determines whether a flip-flop has occurred. For example, when a circuit breaks at A1, the first constant current source 110 decreases, meaning the voltage between A0 and A1 decreases, while the voltage between A2 and A0 remains constant. Therefore, the voltage between A1 and A2 rises. When the voltage between A1 and A2 rises to a certain level, the comparator 310 flips, indicating an open circuit. The same logic applies to a circuit break at A3. This method utilizes the current difference between odd-numbered and even-numbered batteries to achieve open circuit detection. However, the inconsistent current consumption of each battery can cause imbalances between batteries, easily leading to uneven charging and discharging in practical applications. Furthermore, in... Figure 2In the technical solution shown, the protection speed depends on the discharge speed of the internal current source to the external capacitor during the protection process. Therefore, the capacitor also affects the speed of the protection process after an anomaly is detected, which reduces the safety of the battery.

[0019] In summary, existing open circuit protection circuits have some defects. Based on this, the inventors of this invention conducted extensive research and found that, in order to effectively solve the above defects, an open circuit detection circuit is proposed.

[0020] The specific circuit for detecting broken wires will be described below, and various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0021] Please see Figure 3 This invention provides a disconnection detection circuit applied to multiple batteries connected in series. The circuit includes multiple resistors connected in series, a first voltage divider resistor, a second voltage divider resistor, a first current source, a second current source, and a comparison module 11. The multiple batteries are connected in parallel with the multiple resistors one by one. The first end of the first voltage divider resistor is connected to a first connection terminal formed by two resistors. The first end of the second voltage divider resistor is connected to a second connection terminal formed by two other resistors. One or more resistors exist between the first and second connection terminals. The first current source is connected between the second end of the first voltage divider resistor and a first reference voltage terminal. The second current source is connected between the second end of the second voltage divider resistor and the first reference voltage terminal. The first input terminal of the comparison module 11 is connected to the second end of the first voltage divider resistor, and the second input terminal of the comparison module 11 is connected to the second end of the second voltage divider resistor. Its output terminal outputs a signal characterizing the disconnection detection result.

[0022] In this embodiment, by configuring the values ​​of multiple resistors, a first voltage divider resistor, a second voltage divider resistor, a first current source, and a second current source, the relationship between the voltage at the first input terminal and the voltage at the second input terminal of the comparison module 11 is reversed when a disconnection occurs between the disconnection detection circuit and any of the multiple batteries.

[0023] In this embodiment, each battery can be connected in parallel with a resistor, which can be composed of a single resistor element or multiple resistor elements connected in series and / or in parallel.

[0024] In this embodiment, the number of multiple batteries can be greater than or equal to three.

[0025] like Figure 3This is a schematic diagram of the open circuit detection circuit in this embodiment. The multiple batteries include batteries X+1 (B_X+1) to Y-1 (B_Y-1), where XY ≥ 1, and X and Y are both positive integers. The multiple resistors include resistor X+1 (R_X+1) to Y-1 (B_Y-1), where XY ≥ 1, X ≥ 2, and X and Y are both positive integers. This embodiment does not impose specific limitations on the number of batteries or resistors. The node formed by the shared connection of resistor X+1 (R_X+1) and resistor X (R_X) can be considered as the first connection terminal defined in this embodiment; the node formed by the shared connection of resistor Y+1 (R_Y+1) and resistor Y (R_Y) can be considered as the second connection terminal defined in this embodiment. At this time, one or more resistors may exist between the first connection terminal and the second connection terminal. The Xth current source can be considered as the first current source defined in this embodiment, and the Yth current source can be considered as the second current source defined in this embodiment.

[0026] For example Figure 3 Taking the example diagram shown, when the first terminal (first connection terminal) of the Xth resistor R_X is normally connected to the first terminal of the Xth battery B_X:

[0027] Vn = V_X - I_X * R1.

[0028] Where Vn can represent the voltage at the second terminal of the first voltage divider resistor R1, V_X can represent the voltage at the first terminal of the Xth resistor R_X, I_X can represent the current of the Xth current source, and R1 can represent the first voltage divider resistor.

[0029] When the first terminal (first connection terminal) of the Xth resistor R_X is disconnected from the first terminal of the Xth battery B_X:

[0030] Vn=(V_X+1-V_X-1)*R_X / (R_X+1+R_X)-I_X*R1.

[0031] Where V_X+1 can represent the voltage at the first terminal of the Xth resistor R_X+1, V_X-1 can represent the voltage at the first terminal of the (X-1)th resistor R_X-1, R_X can represent the Xth resistor, R_X+1 can represent the (X+1)th resistor, and R1 can represent the first voltage divider resistor.

[0032] When the first terminal (second connection terminal) of the Y-th resistor R_Y is normally connected to the first terminal of the Y-th battery B_Y:

[0033] Vm = V_Y - I_Y * R2.

[0034] Where Vm can represent the voltage at the second terminal of the second voltage divider resistor R2, V_Y can represent the voltage at the first terminal of the Y-th resistor R_Y, I_Y can represent the current of the Y-th current source, and R2 can represent the second voltage divider resistor.

[0035] When the first terminal (second connection terminal) of the Y-th resistor R_Y is disconnected from the first terminal of the Y-th battery B_Y:

[0036] Vm=(V_Y+1-V_Y-1)*R_Y / (R_Y+1+R_Y)-I_Y*R2.

[0037] Where V_Y+1 can represent the voltage at the first terminal of the (Y+1)th resistor R_Y+1, V_Y-1 can represent the voltage at the first terminal of the (Y-1)th resistor, R_Y can represent the Yth resistor, R_Y+1 can represent the (Y+1)th resistor, and R2 can represent the second voltage divider resistor.

[0038] When no disconnection occurs, Vm is satisfied. <Vn:

[0039] V_Y-I_Y*R2 <V_X-I_X*R1。

[0040] When the first terminal (first connection terminal) of the Y-th resistor R_Y is disconnected from the first terminal of the Y-th battery B_Y, Vm > Vn is satisfied:

[0041] V_Y-I_Y*R2>(V_X+1-V_X-1)*R_X / (R_X+1+R_X)-I_X*R1

[0042] When the first terminal (second connection terminal) of the (N-2)th resistor R_N-2 is disconnected from the first terminal of the (N-2)th battery B_N-2, Vm > Vn is satisfied:

[0043] (V_Y+1-V_Y-1)*R_Y / (R_Y+1+R_Y)-I_Y*R2>V_X-I_X*R1

[0044] It can be observed that when a disconnection occurs at the first or second connection terminal, the relative magnitude relationship between the voltage at the first input terminal and the voltage at the second input terminal of the comparison module 11 will be reversed, thus obtaining a result used to characterize the disconnection.

[0045] More specifically, such as Figure 4This illustration shows an application scenario of the open circuit detection circuit provided in this embodiment. In this case, a resistor exists between the first connection terminal and the second connection terminal. The multiple batteries include the (N-2)th battery B_N-2, the (N-1)th battery B_N-1, and the Nth battery B_N. The multiple resistors include the (N-2)th resistor R_N-2, the (N-1)th resistor R_N-1, and the Nth resistor R_N. The node formed by the common connection of the (N-1)th resistor R_N-1 and the Nth resistor R_N can be considered as the first connection terminal defined in this embodiment; the node formed by the common connection of the (N-2)th resistor R_N-2 and the (N-1)th resistor R_N-1 can be considered as the second connection terminal defined in this embodiment. The (N-1)th current source can be considered as the first current source defined in this embodiment, and the (N-2)th current source can be considered as the second current source defined in this embodiment.

[0046] For example Figure 4 Taking the example diagram shown, when the first terminal (first connection terminal) of the (N-1)th resistor R_N-1 is normally connected to the first terminal of the (N-1)th battery B_N-1:

[0047] Vn=V_N-1-I_N-1*R1.

[0048] Where Vn can represent the voltage at the second terminal of the first voltage divider resistor R1, V_N-1 can represent the voltage at the first terminal of the (N-1)th resistor R_N-1, I_N-1 can represent the current of the (N-1)th current source, and R1 can represent the first voltage divider resistor.

[0049] When the first terminal (first connection terminal) of the (N-1)th resistor R_N-1 is disconnected from the first terminal of the (N-1)th battery B_N-1:

[0050] Vn=(V_N-V_N-2)*R_N-1 / (R_N-1+R_N)-I_N-1*R1.

[0051] Where V_N can represent the voltage at the first terminal of the Nth resistor R_N, V_N-2 can represent the voltage at the first terminal of the (N-2)th resistor R_N-2, R_N-1 can represent the (N-1)th resistor, R_N can represent the Nth resistor, and R1 can represent the first voltage divider resistor.

[0052] When the first terminal (second connection terminal) of the (N-2)th resistor R_N-2 is normally connected to the first terminal of the (N-2)th battery B_N-2:

[0053] Vm=V_N-2-I_N-2*R2.

[0054] Where Vm can represent the voltage at the second terminal of the second voltage divider resistor R2, V_N-2 can represent the voltage at the first terminal of the (N-2)th resistor R_N-2, I_N-2 can represent the current of the (N-2)th current source, and R2 can represent the second voltage divider resistor.

[0055] When the first terminal (second connection terminal) of the (N-2)th resistor R_N-2 is disconnected from the first terminal of the (N-2)th battery B_N-2:

[0056] Vm=(V_N-1-V_N-3)*R_N-2 / (R_N-1+R_N-2)-I_N-2*R2.

[0057] Where V_N-1 can represent the voltage at the first terminal of the (N-1)th resistor R_N-1, V_N-3 can represent the voltage at the first terminal of the (N-3)th resistor, R_N-2 can represent the (N-2)th resistor, R_N-1 can represent the (N-1)th resistor, and R2 can represent the second voltage divider resistor.

[0058] When no disconnection occurs, Vm is satisfied. <Vn:

[0059] V_N-2-I_N-2*R2 <V_N-1-I_N-1*R1。

[0060] When the first terminal (first connection terminal) of the (N-1)th resistor R_N-1 is disconnected from the first terminal of the (N-1)th battery B_N-1, Vm > Vn is satisfied:

[0061] V_N-2-I_N-2*R2>(V_N-V_N-2)*R_N-1 / (R_N-1+R_N)-I_N-1*R1.

[0062] When the first terminal (second connection terminal) of the (N-2)th resistor R_N-2 is disconnected from the first terminal of the (N-2)th battery B_N-2, Vm > Vn is satisfied:

[0063] (V_N-1-V_N-3)*R_N-2 / (R_N-1+R_N-2)-I_N-2*R2>V_N-1-I_N-1*R1

[0064] It can be observed that when a disconnection occurs at the first or second connection terminal, the relative magnitude relationship between the voltage at the first input terminal and the voltage at the second input terminal of the comparison module 11 will be reversed, thus obtaining a result used to characterize the disconnection.

[0065] like Figure 5This illustration shows another application scenario of the open circuit detection circuit provided in this embodiment. In this case, there are two resistors between the first connection terminal and the second connection terminal. The multiple batteries include battery N-4 (B_N-4), battery N-3 (B_N-3), battery N-2 (B_N-2), battery N-1 (B_N-1), and battery N (B_N). The multiple resistors include resistor N-4 (R_N-4), resistor N-3 (R_N-3), resistor N-2 (R_N-2), resistor N-1 (R_N-1), and resistor N (R_N). The node formed by the common connection of resistor N-1 (R_N-1) and resistor N (R_N) can be considered as the first connection terminal defined in this embodiment; the node formed by the common connection of resistor N-3 (R_N-3) and resistor N-2 (R_N-2) can be considered as the second connection terminal defined in this embodiment. The N-1 current source can be considered as the first current source defined in this embodiment, and the N-3 current source can be considered as the second current source defined in this embodiment.

[0066] For example Figure 5 Taking the example diagram shown, when the first terminal (first connection terminal) of the (N-1)th resistor R_N-1 is normally connected to the first terminal of the (N-1)th battery B_N-1:

[0067] Vn=V_N-1-I_N-1*R1.

[0068] Where Vn can represent the voltage at the second terminal of the first voltage divider resistor R1, V_N-1 can represent the voltage at the first terminal of the (N-1)th resistor R_N-1, I_N-1 can represent the current of the (N-1)th current source, and R1 can represent the first voltage divider resistor.

[0069] When the first terminal (first connection terminal) of the (N-1)th resistor R_N-1 is disconnected from the first terminal of the (N-1)th battery B_N-1:

[0070] Vn=(V_N-V_N-2)*R_N-1 / (R_N-1+R_N)-I_N-1*R1.

[0071] Where V_N can represent the voltage at the first terminal of the Nth resistor R_N, V_N-2 can represent the voltage at the first terminal of the (N-2)th resistor R_N-2, R_N-1 can represent the (N-1)th resistor, R_N can represent the Nth resistor, and R1 can represent the first voltage divider resistor.

[0072] When the first terminal (second connection terminal) of the (N-3)th resistor R_N-3 is normally connected to the first terminal of the (N-3)th battery B_N-3:

[0073] Vm=V_N-3-I_N-3*R2.

[0074] Where Vm can represent the voltage at the second terminal of the second voltage divider resistor R2, V_N-2 can represent the voltage at the first terminal of the (N-2)th resistor R_N-2, I_N-3 can represent the current of the (N-3)th current source, and R2 can represent the second voltage divider resistor.

[0075] When the first terminal (second connection terminal) of the (N-2)th resistor R_N-2 is disconnected from the first terminal of the (N-2)th battery B_N-2:

[0076] Vm=(V_N-2-V_N-4)*R_N-3 / (R_N-2+R_N-3)-I_N-3*R2.

[0077] Where V_N-2 can represent the voltage at the first terminal of the (N-2)th resistor R_N-2, V_N-4 can represent the voltage at the first terminal of the (N-4)th resistor, R_N-2 can represent the (N-2)th resistor, R_N-3 can represent the (N-3)th resistor, and R2 can represent the second voltage divider resistor.

[0078] When no disconnection occurs, Vm is satisfied. <Vn:

[0079] V_N-3-I_N-3*R2 <V_N-1-I_N-1*R1。

[0080] When the first terminal (first connection terminal) of the (N-1)th resistor R_N-1 is disconnected from the first terminal of the (N-1)th battery B_N-1, Vm > Vn is satisfied:

[0081] V_N-3-I_N-3*R2>(V_N-V_N-2)*R_N-1 / (R_N-1+R_N)-I_N-1*R1

[0082] When the first terminal (second connection terminal) of the (N-2)th resistor R_N-2 is disconnected from the first terminal of the (N-2)th battery B_N-2, Vm > Vn is satisfied:

[0083] (V_N-2-V_N-4)*R_N-3 / (R_N-2+R_N-3)-I_N-3*R2>V_N-1-I_N-1*R1

[0084] It can be observed that when a disconnection occurs at the first or second connection terminal, the relative magnitude relationship between the voltage at the first input terminal and the voltage at the second input terminal of the comparison module 11 will be reversed, thus obtaining a result used to characterize the disconnection.

[0085] Therefore, in this embodiment, by configuring the values ​​of the resistor connected in parallel with the battery, the first voltage divider resistor R1, the second voltage divider resistor R2, the first current source, and the second current source, the relationship between Vm and Vn when a disconnection occurs is reversed compared to the relationship between Vm and Vn when no disconnection occurs, so that the comparison module 11 can detect that a disconnection has occurred.

[0086] In this embodiment, by cleverly designing the connection relationship between the resistor connected in parallel with the battery and the first voltage divider resistor R1, the second voltage divider resistor R2, the first current source, and the second current source, a comparison module 11 can detect whether there is a disconnection between the two batteries and the disconnection detection circuit, simplifying the circuit and reducing power consumption. At the same time, the comparison module 11 can use a common comparator without mismatch, reducing the design difficulty.

[0087] In this embodiment, when the battery is disconnected from the first connection terminal or the battery is disconnected from the second connection terminal, the relative magnitude relationship between the voltage of the first input terminal and the voltage of the second input terminal is reversed.

[0088] Furthermore, such as Figure 6 As shown, the open circuit detection circuit may further include a reference current generation module, which can be used to generate a reference current, obtain a first current source by mirroring according to a first preset ratio, and obtain a second current source by mirroring according to a second preset ratio.

[0089] In this embodiment, the first current source and the second current source can be obtained by mirroring. The first preset ratio and the second preset ratio can be the same or different.

[0090] It should be noted that the magnitudes of the first and second current sources do not change regardless of whether a wire break occurs or not. Therefore, based on the relative magnitudes of the resistors connected in parallel with the battery, the voltage relationship between the second terminals of the first voltage divider resistor R1 and the second voltage divider resistor R2 changes when a wire break occurs, thereby detecting whether a wire break has occurred.

[0091] Specifically, such as Figure 6As shown, the reference current generation module may include a first switch P1, a second switch P2, and a third switch P3. The first terminal of the first switch P1 is connected to the reference current Iref. The second terminals of the first switch P1, the second terminals of the second switch P2, and the third switch P3 are connected to the first reference voltage terminal V1. The first terminal of the first switch P1 is connected to the third terminals of the first switch P1, the second switch P2, and the third switch P3. The first terminal of the second switch P2 is connected to the second terminal of the first voltage divider resistor R1 and the second input terminal of the comparison module 11. The first terminal of the third switch P3 is connected to the second terminal of the second voltage divider resistor R2 and the first input terminal of the comparison module 11.

[0092] In this embodiment, the first switch P1, the second switch P2, and the third switch P3 can all be N-type MOSFETs. The first terminal of each switch P1, the second switch P2, and the third switch P3 can be the drain, the second terminal of each switch P3 can be the source, and the third terminal of each switch P3 can be the gate. A first preset ratio is obtained by configuring the width-to-length ratio between the first switch P1 and the second switch P2; a second preset ratio is obtained by configuring the width-to-length ratio between the first switch P1 and the third switch P3.

[0093] Furthermore, as one implementation method of this embodiment, such as Figure 4 As shown, the multiple batteries may include the (N-2)th battery, the (N-1)th battery, and the Nth battery; the multiple resistors may include the (N-2)th resistor, the (N-1)th resistor, and the Nth resistor, where N ≥ 3 and N is a positive integer; the (N-2)th resistor and the (N-1)th resistor are connected to form a first connection terminal, and the (N-1)th resistor and the Nth resistor are connected to form a second connection terminal; the first current source is the (N-1)th current source, and the second current source is the (N-2)th current source.

[0094] The implementation principle of this embodiment can be referred to the case where there is a resistor between the first connection terminal and the second connection terminal, which will not be repeated here. In this embodiment, by configuring the values ​​of the (N-2)th resistor R_N-2, the (N-1)th resistor R_N-1, the Nth resistor R_N, the first voltage divider resistor R1, the second voltage divider resistor R2, the (N-1)th current source I_N-1, and the (N-2)th current source I_N-2, the relationship between Vm and Vn when a break occurs is reversed compared to the relationship when no break occurs, so that the comparison module 11 can detect that a break has occurred.

[0095] In this embodiment, by cleverly designing the parallel connection relationship between the (N-2)th resistor R_N-2, the (N-1)th resistor R_N-1, the Nth resistor R_N, the first voltage divider resistor R1, the second voltage divider resistor R2, the (N-1)th current source I_N-1, the (N-2)th current source I_N-2, and the comparison module 11, the (N-2)th resistor R_N-2, the (N-1)th resistor R_N-1, and the Nth resistor R_N have differences. Based on the differences between the (N-2)th resistor R_N-2, the (N-1)th resistor R_N-1, and the Nth resistor R_N, a single comparison module 11 can detect whether there is a break in the connection between the two batteries and the break detection circuit, simplifying the circuit and reducing power consumption. At the same time, the comparison module 11 can use a common comparator without mismatch, reducing the design difficulty.

[0096] In some embodiments, the resistance values ​​of the (N-2)th resistor R_N-2 and the Nth resistor R_N can be configured to have the same relative magnitude as the resistance value of the (N-1)th resistor R_N-1. Specifically, the (N-2)th resistor R_N-2 > the (N-1)th resistor R_N-1 < the Nth resistor R_N, or the (N-2)th resistor R_N-2 < the (N-1)th resistor R_N-1 > the Nth resistor R_N.

[0097] In some embodiments, the (N-2)th resistor R_N-2 can have the same resistance value as the (N-1)th resistor R_N-1, thereby reducing the design difficulty of adapting the first voltage divider resistor R1, the second voltage divider resistor R2, the (N-1)th current source I_N-1, and the (N-2)th current source I_N-2. When there are many series-connected batteries, the connection relationship between the (N-2)th resistor R_N-2, the (N-1)th resistor R_N-1, the Nth resistor R_N, the first voltage divider resistor R1, the second voltage divider resistor R2, the (N-1)th current source I_N-1, the (N-2)th current source I_N-2, and the comparison module 11 provided in this embodiment can be adaptively replicated without redesigning the circuit structure.

[0098] It is important to note that in this embodiment, by individually configuring the resistance values ​​of the (N-2)th resistor R_N-2 and the Nth resistor R_N to be consistent with the relative magnitude of the resistance value of the (N-1)th resistor R_N-1, the current magnitudes of the (N-1)th current source I_N-1 and the (N-2)th current source I_N-2 can remain unchanged regardless of whether a break in the circuit occurs or not. That is, for break detection of different multi-cell batteries, only the values ​​of the (N-2)th resistor R_N-2, the (N-1)th resistor R_N-1, and the Nth resistor R_N need to be changed to ensure that the magnitude relationship between Vm and Vn meets the detection requirements, without needing to adjust the values ​​of the (N-1)th current source I_N-1 and the (N-2)th current source I_N-2, thus improving the adaptability of the break detection circuit.

[0099] In some embodiments, the first reference voltage terminal V1 can be connected to the negative terminal of the (N-2)th battery B_N-2. For example... Figure 4 As shown, the negative terminal of the (N-2)th battery B_N-2 is also equivalent to the positive terminal of the (N-3)th battery. If the number of batteries connected in series is 3, the negative terminal of the (N-2)th battery B_N-2 is equivalent to the reference ground. In this embodiment, the (N-1)th current source I_N-1 is connected between the second terminal of the first voltage divider resistor R1 and the negative terminal of the (N-2)th battery B_N-2, and the (N-2)th current source I_N-2 is connected between the second terminal of the second voltage divider resistor R2 and the negative terminal of the (N-2)th battery B_N-2. This reduces the current required by the (N-1)th current source I_N-1 and the (N-2)th current source I_N-2, thereby reducing the complexity of the circuit design and reducing power consumption.

[0100] Furthermore, as one implementation method of this embodiment, such as Figure 7 As shown, the open circuit detection circuit also includes a first transistor M1, a second transistor M2, and a third transistor M3. The first terminal of the first transistor M1 is connected to the positive terminal of the Nth battery B_N; the first terminal of the second transistor M2 is connected to the negative terminal of the (N-1)th battery B_N-2, and the second terminal of the second transistor M2 is connected to the third terminal of the second transistor M2, the second terminal of the first transistor M1, and the third terminal of the first transistor M1; the first terminal of the third transistor M3 is connected to the positive terminal of the Nth battery B_N, the second terminal of the third transistor M3 is connected to the positive terminal of the power supply of the comparison module 11, the third terminal of the third transistor M3 is connected to the second terminal of the second transistor M2, and the negative terminal of the power supply of the comparison module 11 is connected to the negative terminal of the (N-2)th battery B_N-2.

[0101] In this embodiment, the first terminal of the first transistor M1, the second transistor M2, and the third transistor M3 can be the drain, the second terminal of the first transistor M1, the second transistor M2, and the third transistor M3 can be the source, and the third terminal of the first transistor M1, the second transistor M2, and the third transistor M3 can be the gate. Figure 7 As shown, the first transistor M1, the second transistor M2, and the third transistor M3 can be N-type MOS transistors.

[0102] In this embodiment, the first transistor M1 and the second transistor M2 provide a stable gate drive voltage for the third transistor M3, and the third terminal of the third transistor M3 provides a stable voltage for the positive power supply terminal of the comparison module 11, so that the high level output by the comparison module 11 is relatively stable and can be easily recognized by the circuit connected to the output terminal of the comparison module 11.

[0103] In some embodiments, such as Figure 7As shown, the open circuit detection circuit provided in this embodiment may further include a third voltage divider resistor R3, an Nth current source I_N, and a detection module 12. The first terminal of the third voltage divider resistor R3 is connected to the first terminal of the Nth resistor R_N; the Nth current source I_N is connected between the second terminal of the third voltage divider resistor R3 and the second reference voltage terminal V2; the detection module 12 is connected to the second terminal of the third voltage divider resistor R3, and outputs a signal based on the voltage at this second terminal to characterize the open circuit detection result.

[0104] In this embodiment, the second reference voltage terminal V2 can be the reference ground terminal.

[0105] In this embodiment, when the first terminal of the Nth battery B_N is normally connected to the first terminal of the third voltage divider resistor R3, the voltage at the second terminal of the third voltage divider resistor R3 satisfies:

[0106] Vx = V_N - I_N * R3.

[0107] Where Vx can represent the second terminal voltage of the third voltage divider resistor R3, V_N can represent the positive terminal voltage of the Nth battery B_N, I_N can represent the Nth current source, and R3 can represent the third voltage divider resistor.

[0108] When the first terminal of the Nth battery B_N is disconnected from the first terminal of the third voltage divider resistor R3, the voltage at the second terminal of the third voltage divider resistor R3 satisfies:

[0109] Vx = V_N-1 - I_N * (R_N + R3).

[0110] Where V_N-1 can represent the positive voltage of the (N-1)th battery B_N-1, and R_N can represent the Nth resistor.

[0111] In this embodiment, when the detection module 12 receives a signal indicating that the voltage Vx at the second terminal of the third voltage divider resistor R3 changes from V_N-I_N*R3 to V_N-1-I_N*(R_N+R3), it confirms that the first terminal of the Nth battery B_N is disconnected from the first terminal of the third voltage divider resistor R3. Through the implementation of this embodiment, disconnection detection can be performed on the highest-value battery in a series-connected battery configuration, and it can be compared with... Figure 3 The disconnection detection method shown can be used in conjunction with other methods to detect the disconnection of each battery cell, saving on components (such as the current source and the comparison module 11) and simplifying the circuit structure.

[0112] To better understand this technical solution, such as Figure 8As shown, taking a series connection of 5 battery cells as an example, the working method of the disconnection detection circuit is described in detail: The series-connected batteries are battery 1 B_1, battery 2 B_2, battery 3 B_3, battery 4 B_4, and battery 5 B_5, and the series-connected resistors are resistor 1 R_1, resistor 2 R_2, resistor 3 R_3, resistor 4 R_4, and resistor 5 R_5. Battery 1 B_1, battery 2 B_2, battery 3 B_3, battery 4 B_4, and battery 5 B_5 are connected in parallel with resistor 1 R_1, resistor 2 R_2, resistor 3 R_3, resistor 4 R_4, and resistor 5 R_5. For battery 1 B_1 and battery 2 B_2, a comparison module 11 is configured accordingly, and for battery 3 B_3 and battery 4 B_4, a comparison module 11 is configured accordingly. At the same time, the following resistors are pre-configured: first resistor R_1 > second resistor R_2 < third resistor R_3 > fourth resistor R_4 < fifth resistor R_5, and first resistor R_1 = third resistor R_3 = fifth resistor R_5.

[0113] The positive terminal voltage of battery B_1 is V_1, the positive terminal voltage of battery B_2 is V_2, the positive terminal voltage of battery B_3 is V_3, the positive terminal voltage of battery B_4 is V_4, and the positive terminal voltage of battery B_5 is V_5. The second terminal voltage of the first voltage divider resistor R1 corresponding to the second resistor R_2 is Vn1, the second terminal voltage of the second voltage divider resistor R2 corresponding to the first resistor R_1 is Vm1, the second terminal voltage of the first voltage divider resistor R1 corresponding to the fourth resistor R_4 is Vn2, and the second terminal voltage of the second voltage divider resistor R2 corresponding to the third resistor R_3 is Vm2. The current of the first current source is I_1, the current of the second current source is I_2, the current of the third current source is I_3, and the current of the fourth current source is I_4. The positive terminals of batteries B_1, B_2, B_3, B_4, and B_5 are b, d, f, h, and j, respectively, and the first terminals of resistors R_1, R_2, R_3, R_4, and R_5 are a, c, e, g, and i, respectively.

[0114] When a and b are connected normally, Vm1 = V_1 - I_1 * R2; when a and b are disconnected, Vm1 = V_2 * R_1 / (R_1 + R_2) - I_2 × R2.

[0115] When c and d are connected normally, Vn1 = V_2 - I_2 * R1; when c and d are disconnected, Vn1 = (V_3 - V_1) * R_2 / (R_2 + R_3) - I_2 × R1.

[0116] When e and f are connected normally, Vm2 = V_3 - I_3 * R2; when e and f are disconnected, Vm2 = (V_4 - V_2) * R_3 / (R_3 + R_4) - I_3 × R2.

[0117] When g and h are connected normally, Vn2 = V_4 - I_4 * R1; when g and h are disconnected, Vn2 = (V_5 - V_3) * R_4 / (R_4 + R_5) - I_4 × R1.

[0118] ① When each battery and resistor are properly connected, the following formula is satisfied:

[0119] Vn1(V_2-I_2*R1)>Vm1(V_1-I_1*R2)

[0120] Vn2(V_4-I_4*R1)>Vm2(V_3-I_3*R2)

[0121] ② When lines a and b are broken, the following formula is satisfied:

[0122] Vn1(V_2-I_2*R1) <Vm1=V_2*R_1 / (R_1+R_2)-I_2×R2

[0123] ③ When c and d are disconnected, the following formula is satisfied:

[0124] Vn1((V_3-V_1)*R_2 / (R_2+R_3)-I_2×R1) <Vm1(V_1-I_1*R2)

[0125] ④ When e and f are disconnected, the following formula is satisfied:

[0126] Vn2(V_4-I_4*R1) <Vm2((V_4-V_2)*R_3 / (R_3+R_4)-I_3×R2)

[0127] ⑤ When g and h are disconnected, the following formula is satisfied:

[0128] Vn2((V_5-V_3)*R_4 / (R_4+R_5)-I_4×R1) <Vm2(V_3-I_3*R2)

[0129] In this embodiment, by specially configuring the first resistor R_1, the second resistor R_2, the third resistor R_3, the fourth resistor R_4, and the fifth resistor R_5, the relative magnitude relationship between the resistors is cleverly utilized so that when a wire break occurs, the relative magnitude relationship between the voltage of the first voltage divider resistor R1 and the voltage at the second end of the second voltage divider resistor R2 changes.

[0130] In this embodiment, the values ​​of the (N-2)th resistor, the (N-1)th resistor, the Nth resistor, the first voltage divider resistor, the second voltage divider resistor, the (N-1)th current source, and the (N-2)th current source are configured so that the result output by the comparison module 11 is reversed when the first connection terminal or the second connection terminal is disconnected.

[0131] By cleverly designing the connection relationship between the resistor connected in parallel with the battery and the first voltage divider resistor R1, the second voltage divider resistor R2, the first current source, and the second current source, a comparison module 11 can detect whether there is a disconnection between the two batteries and the disconnection detection circuit, simplifying the circuit and reducing power consumption. At the same time, the comparison module 11 can use a common comparator without mismatch, reducing the design difficulty.

[0132] This invention also provides a wire breakage detection chip, which includes any of the wire breakage detection circuits provided in the above embodiments. The description of this wire breakage detection chip is provided in the foregoing embodiments and will not be repeated here.

[0133] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A wire breakage detection circuit, applied to multiple batteries connected in series, characterized in that, include: Multiple resistors are connected in series, and the multiple batteries are connected in parallel with the multiple resistors one by one; The first voltage divider resistor has its first end connected to a first connection end formed by two of the plurality of resistors; The second voltage divider resistor has its first end connected to a second connection end formed by two of the plurality of resistors, and there is one or more of the plurality of resistors between the first connection end and the second connection end; A first current source is connected between the second terminal of the first voltage divider resistor and the first reference voltage terminal; The second current source is connected between the second terminal of the second voltage divider resistor and the first reference voltage terminal; The comparison module has a first input terminal connected to the second terminal of the first voltage divider resistor, a second input terminal connected to the second terminal of the second voltage divider resistor, and an output terminal that outputs a signal characterizing the wire breakage detection result. When the battery is disconnected from the first connection terminal or the battery is disconnected from the second connection terminal, the relative magnitude relationship between the voltage at the first input terminal and the voltage at the second input terminal is reversed.

2. The open circuit detection circuit according to claim 1, characterized in that, The open circuit detection circuit also includes: A reference current generating module for generating a reference current obtains the first current source by mirroring it according to a first preset ratio, and obtains the second current source by mirroring it according to a second preset ratio.

3. The open circuit detection circuit according to any one of claims 1 to 2, characterized in that, The multiple batteries include the (N-2)th battery, the (N-1)th battery, and the Nth battery; the multiple resistors include the (N-2)th resistor, the (N-1)th resistor, and the Nth resistor, where N ≥ 3 and N is a positive integer; the (N-2)th resistor is connected to the (N-1)th resistor to form the first connection terminal, and the (N-1)th resistor is connected to the Nth resistor to form the second connection terminal; the first current source is the (N-1)th current source, and the second current source is the (N-2)th current source.

4. The open circuit detection circuit according to claim 3, characterized in that, The open circuit detection circuit also includes: The first transistor has its first terminal connected to the positive terminal of the Nth battery; The second transistor has its first terminal connected to the negative terminal of the N-2 battery, and its second terminal connected to the third terminal of the second transistor, the second terminal of the first transistor, and the third terminal of the first transistor. The third transistor has its first terminal connected to the positive terminal of the Nth battery, its second terminal connected to the positive terminal of the power supply of the comparison module, its third terminal connected to the second terminal of the second transistor, and the negative terminal of the power supply of the comparison module connected to the negative terminal of the (N-2)th battery.

5. The open circuit detection circuit according to claim 3, characterized in that, Configure the values ​​of the (N-2)th resistor, the (N-1)th resistor, the Nth resistor, the first voltage divider resistor, the second voltage divider resistor, the (N-1)th current source, and the (N-2)th current source so that the result output by the comparison module is reversed when the first connection terminal or the second connection terminal is disconnected.

6. The open circuit detection circuit according to claim 3, characterized in that, The relative magnitudes of the resistance values ​​of the (N-2)th resistor, the Nth resistor, and the (N-1)th resistor are consistent.

7. The open circuit detection circuit according to claim 3, characterized in that, Also includes: The third voltage divider resistor has its first end connected to the first end of the Nth resistor; The Nth current source is connected between the second terminal of the third voltage divider resistor and the second reference voltage terminal; The detection unit is connected to the second terminal of the third voltage divider resistor, and outputs a signal based on the voltage at the second terminal to characterize the result of the wire breakage detection.

8. A wire breakage detection chip, characterized in that, Includes the open circuit detection circuit according to any one of claims 1 to 7.

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