Battery protection chip and battery protection circuit

Abstract

The utility model discloses a battery protection chip and a battery protection circuit, and belongs to the field of batteries. The battery protection chip comprises a control pin, an external resistance detection circuit, a controller and a protection voltage selection circuit, the control pin is electrically connected with the external resistance detection circuit, and the control pin is used for connecting an external resistor; the external resistance detection circuit is electrically connected with the controller, and the external resistance detection circuit is used for detecting a resistance signal corresponding to the external resistance and sending the resistance signal to the controller; the controller is electrically connected with the protection voltage selection circuit, the protection voltage selection circuit provides at least two protection voltages, and the controller is used for receiving the resistance signal and selecting the protection voltage corresponding to the resistance signal from the at least two protection voltages according to the resistance signal.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery protection chip and a battery protection circuit. Background Art

[0002] Lithium batteries are widely used in various electronic devices due to their high energy density, long service life, high rated voltage, and environmental protection. In order to avoid overcharging or overdischarging of lithium batteries during use, which may lead to safety hazards, a battery protection chip is usually required to ensure the safety of battery use.

[0003] However, the protection voltage in the current battery protection chip is a fixed value. As long as the voltage system of the lithium battery is adjusted, the corresponding battery protection chip needs to be adjusted accordingly, and the battery protection chip has the problem of poor compatibility. Utility Model Content

[0004] The present application discloses a battery protection chip and a battery protection circuit, which can improve the compatibility of the battery protection chip.

[0005] In a first aspect, an embodiment of the present application discloses a battery protection chip, comprising: a control pin, an external resistance detection circuit, a controller and a protection voltage selection circuit, wherein: the control pin is electrically connected to the external resistance detection circuit, and the control pin is used to connect an external resistor; the external resistance detection circuit is electrically connected to the controller, and the external resistance detection circuit is used to detect a resistance signal corresponding to the external resistor and send the resistance signal to the controller; the controller is electrically connected to the protection voltage selection circuit, and the protection voltage selection circuit provides at least two protection voltages, and the controller is used to receive the resistance signal and select a protection voltage corresponding to the resistance signal from the at least two protection voltages according to the resistance signal.

[0006] Optionally, it also includes a first resistor and a second resistor, and the protection voltage selection circuit includes a first comparator and a protection voltage selection sub-circuit, wherein: the first end of the first resistor is electrically connected to the battery voltage detection pin, the second end of the first resistor is electrically connected to the first end of the second resistor, and the second end of the second resistor is electrically connected to the ground; the first input end of the first comparator is electrically connected to the second end of the first resistor, the second input end of the first comparator is electrically connected to the protection voltage selection sub-circuit, and the output end of the first comparator is electrically connected to the controller; the controller is electrically connected to the control end of the protection voltage selection sub-circuit, wherein the protection voltage selection sub-circuit provides at least two protection voltages.

[0007] Optionally, the protection voltage selection subcircuit includes a level conversion device, a first on-off device, a second on-off device, a first voltage source, and a second voltage source, wherein: the first end of the first on-off device is electrically connected to the second input end of the first comparator, the second end of the first on-off device is electrically connected to the positive electrode of the first voltage source, the negative electrode of the first voltage source is electrically connected to the ground, and the control end of the first on-off device is electrically connected to the controller; the first end of the second on-off device is electrically connected to the second input end of the first comparator, the second end of the second on-off device is electrically connected to the positive electrode of the second voltage source, and the negative electrode of the second voltage source is electrically connected to the ground; the input end of the level conversion device is electrically connected to the controller, and the output end of the level conversion device is electrically connected to the control end of the second on-off device; wherein the control end of the first on-off device and the input end of the level conversion device are connected to the same end of the controller.

[0008] Optionally, the protection voltage selection subcircuit further includes a buffer, an input end of the buffer is electrically connected to the controller, and an output end of the buffer is electrically connected to a control end of the first switching device.

[0009] Optionally, the first on-off device and the second on-off device are on-off devices with the same structure.

[0010] Optionally, the first on-off device and the second on-off device are field effect transistors.

[0011] Optionally, the level conversion device is an inverter.

[0012] Optionally, the external resistance detection circuit includes a third resistor, a second comparator and a third voltage source, wherein: the first input terminal of the second comparator is electrically connected to the first end of the third resistor and the control pin respectively, the second input terminal of the second comparator is electrically connected to the positive electrode of the third voltage source, and the output terminal of the second comparator is electrically connected to the controller; the second end of the third resistor is electrically connected to the battery voltage detection pin; and the negative electrode of the third voltage source is electrically connected to the ground terminal.

[0013] Optionally, the external resistance detection circuit also includes a third on-off device, a first end of the third on-off device is electrically connected to the first end of the third resistor, a second end of the third on-off device is electrically connected to the first input end of the second comparator, and a control end of the third on-off device is electrically connected to the controller.

[0014] In a second aspect, an embodiment of the present application discloses a battery protection circuit, comprising: an external resistor and the battery protection chip described in the first aspect, wherein the external resistor is electrically connected to a control pin of the battery protection chip.

[0015] An embodiment of the present application provides a battery protection chip, which includes a control pin, an external resistance detection circuit, a controller and a protection voltage selection circuit. The control pin is electrically connected to the external resistance detection circuit, the external resistance detection circuit is electrically connected to the controller, and the controller is electrically connected to the protection voltage selection circuit. Since the protection voltage selection circuit provides at least two protection voltages, external resistors of different specifications are connected through the control pin, and the external resistor detection circuit detects a resistance signal corresponding to the external resistor, and sends the detected resistance signal to the controller. The controller controls the protection voltage selection circuit according to the received resistance signal, and selects a protection voltage corresponding to the external resistor from the at least two protection voltages provided by the protection voltage selection circuit, thereby realizing different protection voltage specification selections, which can improve the compatibility of the battery protection chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a battery protection chip disclosed in an embodiment of the present application;

[0017] Figure 2 This is a schematic diagram of an application of a battery protection chip disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0019] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0020] The present application discloses a battery protection chip and a battery protection circuit. Figure 1 A schematic diagram of the structure of a battery protection chip disclosed in an embodiment of the present application.

[0021] like Figure 1As shown, the battery protection chip disclosed in the present application includes a control pin CTL, an external resistance detection circuit 110, a controller 120 and a protection voltage selection circuit 130, wherein: the control pin CTL is electrically connected to the external resistance detection circuit 110, and the control pin CTL is used to connect an external resistor; the external resistance detection circuit 110 is electrically connected to the controller 120, and the external resistance detection circuit 110 is used to detect a resistance signal corresponding to the external resistor, and send the resistance signal to the controller 120; the controller 120 is electrically connected to the protection voltage selection circuit 130, and the protection voltage selection circuit 130 provides at least two protection voltages, and the controller 120 is used to receive the resistance signal, and select a protection voltage corresponding to the resistance signal from the at least two protection voltages according to the resistance signal.

[0022] In the present application, the external resistance detection circuit 110 is used to detect a resistance signal corresponding to an external resistor connected to the control pin CTL, and send the resistance signal to the controller 120. The controller 120 controls the protection voltage selection circuit 130 according to the received resistance signal, and selects a protection voltage corresponding to the resistance signal from at least two protection voltages provided by the protection voltage selection circuit 130, that is, selects a protection voltage corresponding to the external resistor from at least two protection voltages provided by the protection voltage selection circuit 130, thereby realizing different protection voltage specification selections.

[0023] It should be noted that the protection voltage selection circuit 130 in the present application can provide at least two protection voltages. By controlling the pin CTL to connect external resistors of different specifications, the protection voltages selected by the protection voltage selection circuit 130 are also different.

[0024] An embodiment of the present application provides a battery protection chip, which includes a control pin, an external resistance detection circuit 110, a controller 120 and a protection voltage selection circuit 130. The control pin is electrically connected to the external resistance detection circuit 110, the external resistance detection circuit 110 is electrically connected to the controller 120, and the controller 120 is electrically connected to the protection voltage selection circuit 130. Since the protection voltage selection circuit 130 provides at least two protection voltages, external resistors of different specifications are connected through the control pin, and the external resistor detection circuit 110 detects a resistance signal corresponding to the external resistor, and sends the detected resistance signal to the controller 120. The controller 120 controls the protection voltage selection circuit 130 according to the received resistance signal, and selects a protection voltage corresponding to the external resistor from the at least two protection voltages provided by the protection voltage selection circuit 130, thereby realizing different protection voltage specification selections, which can improve the compatibility of the battery protection chip.

[0025] In the embodiments of the present application, Figure 1As shown, the battery protection chip may further include a first resistor R1 and a second resistor R2, and the protection voltage selection circuit 130 may include a first comparator COM1 and a protection voltage selection subcircuit 131, wherein: a first end of the first resistor R1 is electrically connected to a battery voltage detection pin VDD, a second end of the first resistor R1 is electrically connected to a first end of the second resistor R2, and a second end of the second resistor R2 is electrically connected to a ground terminal; a first input end of the first comparator COM1 is electrically connected to a second end of the first resistor R1, a second input end of the first comparator COM1 is electrically connected to the protection voltage selection subcircuit 131, and an output end of the first comparator COM1 is electrically connected to the controller 120; the controller 120 is electrically connected to a control end of the protection voltage selection subcircuit 131, wherein the protection voltage selection subcircuit 131 provides at least two protection voltages.

[0026] It should be noted that the first comparator COM1 may be an overcharge comparator or an over-discharge comparator.

[0027] In the embodiments of the present application, Figure 1 As shown, the protection voltage selection subcircuit 131 may include a level conversion device, a first on-off device Q1, a second on-off device Q2, a first voltage source U1, and a second voltage source U2, wherein: a first end of the first on-off device Q1 is electrically connected to the second input end of the first comparator COM1, a second end of the first on-off device Q1 is electrically connected to the positive electrode of the first voltage source U1, a negative electrode of the first voltage source U1 is electrically connected to the ground, and a control end of the first on-off device Q1 is electrically connected to the controller 120; a first end of the second on-off device Q2 is electrically connected to the second input end of the first comparator COM1, a second end of the second on-off device Q2 is electrically connected to the positive electrode of the second voltage source U2, and a negative electrode of the second voltage source U2 is electrically connected to the ground; an input end of the level conversion device is electrically connected to the controller 120, and an output end of the level conversion device is electrically connected to the control end of the second on-off device Q2; wherein the control end of the first on-off device Q1 and the input end of the level conversion device are connected to the same end of the controller 120.

[0028] Furthermore, the first on-off device Q1 and the second on-off device Q2 are on-off devices with the same structure. For example, the first on-off device Q1 and the second on-off device Q2 may be N-type metal oxide semiconductors (Negative channel-Metal-Oxide-Semiconductor, NMOS), or the first on-off device Q1 and the second on-off device Q2 may be P-type metal oxide semiconductors (Positive channel-Metal-Oxide-Semiconductor, PMOS), which is not specifically limited in the present application. The level conversion device may be an inverter.

[0029] It should be noted that the voltage values ​​provided by the first voltage source U1 and the second voltage source U2 in the present application are different.

[0030] After receiving the signal corresponding to the external resistance detected by the external resistance detection circuit 110, the controller 120 sends a first control signal to the protection voltage selection subcircuit 131 according to the received signal, and controls the protection voltage selection subcircuit 131 to select the protection voltage corresponding to the external resistance. Exemplarily, when the first control signal sent by the controller 120 is at a high level, the first terminal and the second terminal of the first on-off device Q1 are connected, and the voltage corresponding to the first voltage source U1 is used as the protection voltage of the battery protection chip. When the first control signal sent by the controller 120 is at a low level, the first terminal and the second terminal of the second on-off device Q2 are connected, and the voltage corresponding to the second voltage source U2 is used as the protection voltage of the battery protection chip.

[0031] In one implementation, the first on-off device Q1 and the second on-off device Q2 may be field effect transistors. In addition, the first on-off device Q1 and the second on-off device Q2 may also be triodes, or other structures capable of achieving the above functions.

[0032] In one possible implementation, Figure 1 As shown, the protection voltage selection subcircuit 131 may further include a buffer, the input end of the buffer is electrically connected to the controller 120, and the output end of the buffer is electrically connected to the control end of the first on-off device Q1. In other words, the first control signal sent by the controller 120 reaches the control end of the first on-off device Q1 after passing through the buffer, and the buffer is used to delay the first control signal, playing a role of coordination and buffering.

[0033] It should be noted that a plurality of the protection voltage selection subcircuits 131 described above may be electrically connected to the controller 120 so that the battery protection chip can provide a plurality of optional protection voltages.

[0034] In the embodiments of the present application, Figure 1As shown, the external resistance detection circuit 110 may include a third resistor R3, a second comparator COM2 and a third voltage source U3, wherein: the first input terminal of the second comparator COM2 is electrically connected to the first end of the third resistor R3 and the control pin CTL respectively, the second input terminal of the second comparator COM2 is electrically connected to the positive electrode of the third voltage source U3, and the output terminal of the second comparator COM2 is electrically connected to the controller; the second end of the third resistor R3 is electrically connected to the battery voltage detection pin VDD; the negative electrode of the third voltage source U3 is electrically connected to the ground terminal.

[0035] In the present application, when the control pin CTL is connected to an external resistor, the VDD is divided by the third resistor R3 and the external resistor, the second comparator COM2 detects the divided voltage signal and feeds it back to the controller 120, and the controller 120 controls the protection voltage selection circuit 130 to select the protection voltage corresponding to the external resistor according to the received divided voltage signal.

[0036] In one implementation, Figure 1 As shown, the external resistance detection circuit 110 may further include a third on-off device Q3, a first end of the third on-off device Q3 being electrically connected to the first end of the third resistor R3, a second end of the third on-off device Q3 being electrically connected to the first input end of the second comparator COM2, and a control end of the third on-off device Q3 being electrically connected to the controller 120.

[0037] Exemplarily, the third switching device Q3 may be a field effect transistor or a triode, and the present application does not impose any specific limitation on this.

[0038] Specifically, when the control pin CTL is connected to an external resistor and the battery protection chip is powered on, the controller 120 controls the first end and the second end of the third on-off device Q3 to be turned on, and the VDD is divided by the third resistor R3 and the external resistor. The second comparator COM2 detects the divided voltage signal and feeds it back to the controller 120. The controller 120 controls the protection voltage selection circuit 130 to select the protection voltage corresponding to the external resistor according to the received divided voltage signal. After determining the protection voltage corresponding to the external resistor, the controller 120 controls the first end and the second end of the third on-off device Q3 to be disconnected, thereby reducing the leakage current from VDD to CTL, thereby reducing the self-consumption of the battery protection chip and the battery.

[0039] In the present application, the CTL pin of the battery protection chip described above is a newly added pin based on a 6-pin (PIN) lithium battery protection chip (integrated circuit, IC). The newly added CTL pin can be made at the bottom of the IC to achieve packaging compatibility.

[0040] By adopting the scheme disclosed in the present application, external resistors of different specifications are electrically connected to the CTL pin of the battery protection chip. The external resistor detection circuit 110 electrically connected to the CTL pin in the battery protection chip detects the signal corresponding to the external resistor, and sends the detected signal to the controller 120. The controller 120 controls the protection voltage selection circuit 130 to select the protection voltage corresponding to the external resistor according to the received signal, thereby realizing different protection voltage specification selection through a single protection chip, which can improve the compatibility of the battery protection chip, make the protection board corresponding to the battery protection chip compatible with the protection voltages of different voltage systems, improve product development efficiency and reduce development costs.

[0041] Compared with the related art, there are M types of IC brands, each protection scheme has dual IC protection, and each time the battery cell platform is upgraded, M*2 new protection ICs need to be opened. By adopting the scheme disclosed in the present application, the number of new protection chips can be reduced when the battery cell platform is upgraded. For example, when the protection voltage selection circuit provides two protection voltages, the number of new protection chips can be halved, as shown in the following table.

[0042]

[0043]

[0044] It should be noted that in the above table, V1<V2<V3<V4<V5<V6<V7<V8<V9<V10<V11<V12.

[0045] An embodiment of the present application discloses a battery protection circuit, comprising an external resistor and the battery protection chip described above, wherein the external resistor is electrically connected to a control pin CTL of the battery protection chip.

[0046] It should be noted that the first end of the external resistor is electrically connected to the control pin CTL of the battery protection chip, and the second end of the external resistor is electrically connected to the ground terminal. The specific connection of the external resistor can be as follows Figure 2 As shown, Figure 2 The U1 chip and U2 chip in the system are both battery protection chips. Figure 2 The resistor R7 in is an external resistor connected to the U1 chip. Figure 2 The resistor R8 in FIG. 1 is an external resistor connected to the U2 chip.

[0047] The above embodiments of the present application focus on describing the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0048] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A battery protection chip, characterized in that: include: Control pin, external resistance detection circuit, controller and protection voltage selection circuit, where: The control pin is electrically connected to the external resistance detection circuit, and the control pin is used to connect an external resistor; The external resistance detection circuit is electrically connected to the controller, and the external resistance detection circuit is used to detect a resistance signal corresponding to the external resistance and send the resistance signal to the controller; The controller is electrically connected to the protection voltage selection circuit, the protection voltage selection circuit provides at least two protection voltages, and the controller is used to receive the resistance signal and select a protection voltage corresponding to the resistance signal from the at least two protection voltages according to the resistance signal.

2. The battery protection chip according to claim 1, characterized in that: It also includes a first resistor and a second resistor, and the protection voltage selection circuit includes a first comparator and a protection voltage selection subcircuit, wherein: The first end of the first resistor is electrically connected to the battery voltage detection pin, the second end of the first resistor is electrically connected to the first end of the second resistor, and the second end of the second resistor is electrically connected to the ground; The first input terminal of the first comparator is electrically connected to the second terminal of the first resistor, the second input terminal of the first comparator is electrically connected to the protection voltage selection subcircuit, and the output terminal of the first comparator is electrically connected to the controller; The controller is electrically connected to a control terminal of the protection voltage selection subcircuit, wherein the protection voltage selection subcircuit provides at least two protection voltages.

3. The battery protection chip according to claim 2, characterized in that: The protection voltage selection subcircuit includes a level conversion device, a first on-off device, a second on-off device, a first voltage source, and a second voltage source, wherein: The first end of the first on-off device is electrically connected to the second input end of the first comparator, the second end of the first on-off device is electrically connected to the positive electrode of the first voltage source, the negative electrode of the first voltage source is electrically connected to the ground, and the control end of the first on-off device is electrically connected to the controller; The first end of the second on-off device is electrically connected to the second input end of the first comparator, the second end of the second on-off device is electrically connected to the positive electrode of the second voltage source, and the negative electrode of the second voltage source is electrically connected to the ground end; The input end of the level conversion device is electrically connected to the controller, and the output end of the level conversion device is electrically connected to the control end of the second on-off device; Wherein, the control end of the first on-off device and the input end of the level conversion device are connected to the same end of the controller.

4. The battery protection chip according to claim 3, characterized in that: The protection voltage selection subcircuit further includes a buffer, an input end of the buffer is electrically connected to the controller, and an output end of the buffer is electrically connected to a control end of the first on-off device.

5. The battery protection chip according to claim 3, characterized in that: The first on-off device and the second on-off device are on-off devices with the same structure.

6. The battery protection chip according to claim 5, characterized in that: The first on-off device and the second on-off device are field effect transistors.

7. The battery protection chip according to claim 3, characterized in that: The level conversion device is an inverter.

8. The battery protection chip according to claim 1, characterized in that: The external resistance detection circuit includes a third resistor, a second comparator and a third voltage source, wherein: The first input terminal of the second comparator is electrically connected to the first terminal of the third resistor and the control pin respectively, the second input terminal of the second comparator is electrically connected to the positive electrode of the third voltage source, and the output terminal of the second comparator is electrically connected to the controller; The second end of the third resistor is electrically connected to the battery voltage detection pin; The negative electrode of the third voltage source is electrically connected to the ground.

9. The battery protection chip according to claim 8, characterized in that: The external resistance detection circuit also includes a third on-off device, a first end of the third on-off device is electrically connected to the first end of the third resistor, a second end of the third on-off device is electrically connected to the first input end of the second comparator, and a control end of the third on-off device is electrically connected to the controller.

10. A battery protection circuit, characterized in that: include: An external resistor and a battery protection chip according to any one of claims 1 to 9, wherein the external resistor is electrically connected to a control pin of the battery protection chip.

Images