Battery protection circuits, chips and systems

Abstract

The present invention discloses a battery protection circuit, chip and system, including a timing protection circuit, an anti-interference circuit and a temperature detection circuit; the temperature detection circuit is connected to the temperature detection end and outputs a temperature detection signal; the anti-interference circuit is connected to the timing protection circuit and the temperature detection circuit, enters a delayed output mode according to a first timing signal output by the timing protection circuit, or enters a real-time output mode according to a second timing signal output by the timing protection circuit, processes the temperature detection signal, and outputs a target electrical signal; the timing protection circuit determines whether there is a temperature anomaly according to the target electrical signal, and if there is a temperature anomaly, outputs a first timing signal to the anti-interference circuit, and if there is no temperature anomaly, outputs a second timing signal to the anti-interference circuit. When there is a temperature anomaly, the technical solution causes the anti-interference circuit to delay outputting the target electrical signal, thereby filtering out the influence of environmental interference on the battery protection system and improving the safety of the battery protection system.

Description

Technical Field

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

[0002] When using electronic products, it is necessary to understand temperature information, especially in battery-powered workplaces, because abnormal temperature can easily cause safety accidents and is also detrimental to battery life.

[0003] Normally, NTC (Negative Temperature Coefficient, NTC for short) resistors are used to detect ambient temperature, and the detected ambient temperature is fed back to the battery protection system for monitoring. In order to reduce the power consumption of the battery protection system, the prior art often adopts two methods, namely, sleep mode and time-sharing detection mode. However, there are usually some problems with the time-sharing detection mode, such as being easily affected by environmental interference, causing the battery protection system to respond incorrectly, affecting the reliability of the battery protection system. Therefore, how to improve the reliability of the battery protection system has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] Embodiments of the present invention provide a battery protection circuit, a chip and a system to solve the problem of poor reliability of existing battery protection systems.

[0005] A battery protection circuit, comprising a timing protection circuit, an anti-interference circuit and a temperature detection circuit;

[0006] The temperature detection circuit is connected to the temperature detection terminal and is used to output a temperature detection signal;

[0007] The anti-interference circuit is connected to the timing protection circuit and the temperature detection circuit, and is used to enter a delayed output mode according to a first timing signal output by the timing protection circuit, or to enter a real-time output mode according to a second timing signal output by the timing protection circuit, process the temperature detection signal, and output a target electrical signal;

[0008] The timing protection circuit is used to determine whether there is a temperature abnormality based on the target electrical signal. If there is a temperature abnormality, the first timing signal is output to the anti-interference circuit. If there is no temperature abnormality, the second timing signal is output to the anti-interference circuit.

[0009] Furthermore, the temperature detection circuit is also connected to the timing protection circuit, and is used to enter the real-time detection mode and output the temperature detection signal when receiving the first timing signal; or enter the time-sharing detection mode when receiving the second timing signal.

[0010] Furthermore, the battery protection circuit also includes a time-sharing control circuit;

[0011] The time-sharing control circuit is connected to the temperature detection circuit and is used to output a time-sharing control signal to the temperature detection circuit;

[0012] The temperature detection circuit is further configured to enter a time-sharing detection mode and output the temperature detection signal according to the time-sharing control signal when the second timing signal is received.

[0013] Further, the temperature detection circuit includes a first comparator; the anti-interference circuit includes a first delay circuit and a first signal selection circuit;

[0014] The first input end of the first comparator is used to receive a first reference signal, the second input end of the first comparator is connected to the temperature detection end, and is used to receive a target temperature signal of the temperature detection end, and the output end of the first comparator is connected to the input end of the first delay circuit and the first input end of the first signal selection circuit, and is used to output the temperature detection signal;

[0015] The output end of the first delay circuit is connected to the second input end of the first signal selection circuit, and is used to receive the temperature detection signal and output the temperature detection signal after a first preset time;

[0016] The control end and the output end of the first signal selection circuit are connected to the timing protection circuit, and are used to switch to a first path when receiving the first timing signal, and the first path connects the first delay circuit and the timing protection circuit; when receiving the second timing signal, switch to a second path, and the second path connects the output end of the first comparator and the timing protection circuit.

[0017] Furthermore, the temperature detection circuit further includes a second comparator; the anti-interference circuit further includes a second delay circuit and a second signal selection circuit;

[0018] The first input terminal of the second comparator is used to receive the second reference signal, the second input terminal of the second comparator is connected to the temperature detection terminal, and is used to receive the target temperature signal of the temperature detection terminal, and the output terminal of the second comparator is connected to the input terminal of the second delay circuit and the first input terminal of the second signal selection circuit, and is used to output the temperature detection signal;

[0019] The output end of the second delay circuit is connected to the second input end of the second signal selection circuit, and is used to receive the temperature detection signal and output the temperature detection signal after a first preset time;

[0020] The control end and the output end of the second signal selection circuit are connected to the timing protection circuit, and are used to switch to a third path when receiving the first timing signal, and the third path connects the second delay circuit and the timing protection circuit; when receiving the second timing signal, switch to a fourth path, and the fourth path connects the output end of the second comparator and the timing protection circuit.

[0021] Further, the magnitude of the first reference signal is greater than the magnitude of the second reference signal.

[0022] Furthermore, the battery protection circuit also includes a logic control circuit;

[0023] The timing protection circuit is also used to output a temperature alarm signal after a second preset time when the temperature abnormality exists;

[0024] The logic control circuit is connected to the timing protection circuit and is used to receive the temperature alarm signal and enter a temperature protection mode.

[0025] A battery protection chip comprises the above-mentioned battery protection circuit.

[0026] A battery protection system comprises the battery protection chip mentioned above.

[0027] Further, the battery protection system also includes a first resistor and a thermistor;

[0028] The first resistor and the thermistor are connected in series between a power supply terminal and a ground terminal, and a connection node between the first resistor and the thermistor is connected to a temperature detection terminal of the battery protection chip.

[0029] The above-mentioned battery protection circuit, chip and system connect the temperature detection circuit to the temperature detection end so that the temperature detection circuit outputs a temperature detection signal; and connect the anti-interference circuit to the timing protection circuit and the temperature detection circuit, and make the anti-interference circuit enter a delayed output mode according to the first timing signal output by the timing protection circuit, or enter a real-time output mode according to the second timing signal output by the timing protection circuit, process the temperature detection signal, and output a target electrical signal; and make the timing protection circuit determine whether there is a temperature abnormality according to the target electrical signal, if there is a temperature abnormality, output the first timing signal to the anti-interference circuit, if there is no temperature abnormality, output the second timing signal to the anti-interference circuit, so that when there is a temperature abnormality, the anti-interference circuit can delay the output of the target electrical signal through the delayed output mode of the anti-interference circuit to filter the influence of environmental interference on the temperature abnormality, thereby filtering out the influence of environmental interference on the battery protection system and improving the safety of the battery protection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0031] Figure 1 is a circuit diagram of a battery protection circuit in one embodiment of the present invention;

[0032] Figure 2 is another circuit diagram of a battery protection circuit in one embodiment of the present invention;

[0033] Figure 3 is another circuit diagram of a battery protection circuit in one embodiment of the present invention;

[0034] Figure 4 is another circuit diagram of a battery protection circuit in one embodiment of the present invention;

[0035] Figure 5 is a working waveform diagram of a battery protection circuit in one embodiment of the present invention;

[0036] Figure 6 FIG. 4 is another working waveform diagram of the battery protection circuit in one embodiment of the present invention.

[0037] In the figure: 1. battery protection chip; 10. timing protection circuit; 20. anti-interference circuit; 21. first delay circuit; 22. first signal selection circuit; 23. second delay circuit; 24. second signal selection circuit; 30. temperature detection circuit; 31. first comparator; 32. second comparator; 40. time-sharing control circuit; 50. logic control circuit. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0040] In order to fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0041] The present embodiment provides a battery protection circuit, which is applied to a battery protection chip 1. The battery protection chip 1 is applied to a battery protection system. Exemplarily, the battery protection system includes a battery, a battery protection chip 1 and a load. The battery protection chip 1 is connected to the battery and the load, and is used to protect the battery from charge and discharge.

[0042] This embodiment provides a battery protection circuit. Figure 1 As shown, it includes a timing protection circuit 10, an anti-interference circuit 20 and a temperature detection circuit 30; the temperature detection circuit 30 is connected to the temperature detection terminal RTS, and is used to output a temperature detection signal; the anti-interference circuit 20 is connected to the timing protection circuit 10 and the temperature detection circuit 30, and is used to enter a delayed output mode according to a first timing signal output by the timing protection circuit 10, or enter a real-time output mode according to a second timing signal output by the timing protection circuit 10, process the temperature detection signal, and output a target electrical signal; the timing protection circuit 10 is used to determine whether there is a temperature abnormality according to the target electrical signal, and if there is a temperature abnormality, output a first timing signal to the anti-interference circuit 20, and if there is no temperature abnormality, output a second timing signal to the anti-interference circuit 20.

[0043] In a specific embodiment, the temperature detection circuit 30 is connected to the temperature detection terminal RTS and is used to output a temperature detection signal. Exemplarily, the temperature detection terminal RTS is used to output a target temperature signal. The target temperature signal refers to an electrical signal corresponding to the ambient temperature.

[0044] As an example, the battery protection system also includes a first resistor and a thermistor. The first resistor and the thermistor. The first resistor and the thermistor are connected in series between the power supply terminal RTV and the ground terminal, and the connection node between the first resistor and the thermistor is connected to the temperature detection terminal RTS. The first resistor and the thermistor form a voltage divider circuit. Among them, the power supply terminal RTV can be set on the battery protection chip 1, and the battery protection chip 1 supplies power to the voltage divider circuit formed by the first resistor and the thermistor through the power supply terminal RTV. It can be understood that the power supply terminal RTV can also be set on other power supply circuits that can supply power to the voltage divider circuit formed by the first resistor and the thermistor. In this example, when the ambient temperature changes, the resistance of the thermistor changes accordingly with the change of the ambient temperature, thereby causing the voltage of the connection node between the first resistor and the thermistor to change, thereby generating an electrical signal corresponding to the ambient temperature at the temperature detection terminal RTS, that is, a target temperature signal.

[0045] In a specific embodiment, the anti-interference circuit 20 is connected to the timing protection circuit 10 and the temperature detection circuit 30. The working mode of the anti-interference circuit 20 includes a delayed output mode and a real-time output mode. Among them, the delayed output mode refers to a working mode of delaying the output of the target electrical signal. Exemplarily, the delayed output mode is a working mode of outputting the target electrical signal after a first preset time after receiving the temperature detection signal. The first preset time can be selected according to actual experience and is not limited here. The real-time output mode refers to a working mode of outputting the target electrical signal in real time. Exemplarily, the delayed output mode is a working mode of directly outputting the target electrical signal after receiving the temperature detection signal. It can be understood that the target electrical signal can be a delayed output temperature detection signal or a real-time output temperature detection signal. Exemplarily, the anti-interference circuit 20 enters the delayed output mode according to the first timing signal output by the timing protection circuit 10, and enters the real-time output mode according to the second timing signal output by the timing protection circuit 10. The first timing signal and the second timing signal are feedback signals generated according to the target electrical signal output by the anti-interference circuit 20. It should be noted that the anti-interference circuit 20 is in the real-time output mode by default. The timing protection circuit 10 outputs the second timing signal by default. In this embodiment, since the battery protection system may be subject to environmental interference, especially power frequency interference, during operation, when the thermistor in the battery protection system is subject to power frequency interference when detecting the ambient temperature, it is easy for the temperature detection terminal RTS to generate an erroneous temperature detection signal, causing the battery protection system to make an erroneous response, thereby affecting the safety performance of the battery protection system. Therefore, the present application ensures that when the temperature detection signal is abnormal, the timing protection circuit 10 outputs the first timing signal, so that the anti-interference circuit 20 enters the delayed output mode, thereby filtering out the influence of power frequency interference on the battery protection system and improving the safety of the battery protection system.

[0046] In a specific embodiment, the timing protection circuit 10 is used to determine whether there is a temperature anomaly according to the target electrical signal. If there is a temperature anomaly, a first timing signal is output to the anti-interference circuit 20. If there is no temperature anomaly, a second timing signal is output to the anti-interference circuit 20. In this embodiment, the timing protection circuit 10 can determine whether there is a temperature anomaly in the ambient temperature according to the target electrical signal. If the timing protection circuit 10 determines that there is a temperature anomaly, the second timing signal is output to the anti-interference circuit 20, so that the anti-interference circuit 20 enters a delayed output mode according to the second timing signal, thereby delaying the anti-interference circuit 20 to output the target electrical signal through the delayed output mode to filter the influence of environmental interference on the temperature anomaly, thereby filtering the influence of environmental interference on the battery protection system, and improving the safety of the battery protection system. If the timing protection circuit 10 determines that there is no temperature anomaly, the first timing signal is output to the anti-interference circuit 20, so that the anti-interference circuit 20 enters a real-time output mode according to the first timing signal, that is, after the anti-interference circuit 20 receives the temperature detection signal, it directly outputs the target electrical signal to the timing protection circuit 10. In this embodiment, the judgment logic and specific circuit structure of the timing protection circuit 10 for determining whether there is a temperature anomaly can adopt technologies known to those skilled in the art, to ensure that when the timing protection circuit 10 determines that there is a temperature anomaly, it outputs a first timing signal to the anti-interference circuit 20, and when the timing protection circuit 10 determines that there is no temperature anomaly, it outputs a second timing signal to the anti-interference circuit 20, which will not be repeated here.

[0047] In this embodiment, the temperature detection circuit 30 is connected to the temperature detection terminal RTS so that the temperature detection circuit 30 outputs a temperature detection signal; the anti-interference circuit 20 is connected to the timing protection circuit 10 and the temperature detection circuit 30, and the anti-interference circuit 20 enters a delayed output mode according to a first timing signal output by the timing protection circuit 10, or enters a real-time output mode according to a second timing signal output by the timing protection circuit 10, processes the temperature detection signal, and outputs a target electrical signal; and the timing protection circuit 10 determines whether there is a temperature abnormality according to the target electrical signal, and if there is a temperature abnormality, outputs a first timing signal to the anti-interference circuit 20, and if there is no temperature abnormality, outputs a second timing signal to the anti-interference circuit 20, so that when there is a temperature abnormality, the anti-interference circuit 20 can delay the output of the target electrical signal through the delayed output mode of the anti-interference circuit 20 to filter the influence of environmental interference on the temperature abnormality, thereby filtering out the influence of environmental interference on the battery protection system and improving the safety of the battery protection system.

[0048] In one embodiment, if Figure 2As shown, the temperature detection circuit 30 is also connected to the timing protection circuit 10, and is used to enter the real-time detection mode and output the temperature detection signal when receiving the first timing signal; or enter the time-sharing detection mode when receiving the second timing signal.

[0049] In a specific embodiment, the real-time monitoring mode refers to a working mode for detecting the temperature detection signal in real time. The time-sharing detection mode refers to a working mode for detecting the temperature detection signal in time.

[0050] Exemplarily, the time-sharing detection mode may be to detect the temperature detection signal at intervals of a preset detection time, or may be to detect the temperature detection signal at a specified preset detection time.

[0051] In this embodiment, when the temperature detection circuit 30 receives the first timing signal, it enters the real-time detection mode and outputs the temperature detection signal to detect whether the ambient temperature remains in an abnormal state, thereby improving the reliability of the temperature detection circuit 30. When the second timing signal is received, it enters the time-sharing detection mode to reduce the overall power consumption of the battery protection system.

[0052] In one embodiment, if Figure 4 As shown, the battery protection circuit also includes a time-sharing control circuit 40; the time-sharing control circuit 40 is connected to the temperature detection circuit 30, and is used to output a time-sharing control signal to the temperature detection circuit 30; the temperature detection circuit 30 is also used to enter a time-sharing detection mode and output a temperature detection signal according to the time-sharing control signal when receiving the second timing signal.

[0053] In this embodiment, when the temperature detection circuit 30 receives the second timing signal, the time-sharing control circuit 40 can control the temperature detection circuit 30 to enter the time-sharing detection mode and output the temperature detection signal to reduce the overall power consumption of the battery protection system. It should be noted that the priority of the first timing signal is higher than the time-sharing control signal. When the temperature detection circuit 30 receives the first timing signal, it enters the real-time monitoring mode to ensure that the ambient temperature can be detected reliably and accurately. The circuit structure and control logic of the time-sharing control circuit 40 can adopt the technology known to those skilled in the art to ensure that the temperature detection circuit 30 can enter the time-sharing detection mode, for example, the temperature detection signal is detected at intervals of a preset detection time, or the temperature detection signal is detected at a specified preset detection time, which is not limited here. Among them, the preset detection time can be selected according to actual experience, which will not be repeated here.

[0054] In one embodiment, if Figure 2As shown, the temperature detection circuit 30 includes a first comparator 31; the anti-interference circuit 20 includes a first delay circuit 21 and a first signal selection circuit 22; the first input end of the first comparator 31 is used to receive the first reference signal VTH, the second input end of the first comparator 31 is connected to the temperature detection end RTS, and is used to receive the target temperature signal of the temperature detection end RTS; the output end of the first comparator 31 is connected to the input end of the first delay circuit 21 and the first input end of the first signal selection circuit 22, and is used to output the temperature detection signal; the output end of the first delay circuit 21 is connected to the second input end of the first signal selection circuit 22, and is used to receive the temperature detection signal, and output the temperature detection signal after the first preset time; the control end and the output end of the first signal selection circuit 22 are connected to the timing protection circuit 10, and are used to switch to the first path when receiving the first timing signal, and the first path connects the first delay circuit 21 and the timing protection circuit 10; when receiving the second timing signal, it switches to the second path, and the second path connects the output end of the first comparator 31 and the timing protection circuit 10.

[0055] In a specific embodiment, the temperature detection circuit 30 defaults to the time-sharing detection mode, and the first signal selection circuit 22 defaults to the second path to reduce the overall power consumption of the battery protection system. The temperature detection circuit 30 detects the temperature detection signal in a time-sharing manner, and the anti-interference circuit 20 selects the second path through the first signal selection circuit 22 to output the target electrical signal to the timing protection circuit 10. The timing protection circuit 10 determines whether there is a temperature anomaly based on the target electrical signal. If there is a temperature anomaly, the timing protection circuit 10 generates a first timing signal and feeds it back to the first signal selection circuit 22 of the anti-interference circuit 20. At this time, the second signal selection circuit 24 selects the first path, and the first delay circuit 21 outputs the temperature detection signal after the first preset time. After the first preset time, the temperature detection signal is output to filter the impact of environmental interference on the temperature anomaly, thereby filtering out the impact of environmental interference on the battery protection system and improving the safety of the battery protection system. When there is no temperature anomaly, the timing protection circuit 10 feeds back the anti-interference circuit 20 to the first signal selection circuit 22 of the anti-interference circuit 20, reselects the second path to output the target electrical signal to the timing protection circuit 10, and the temperature detection circuit 30 re-enters the time-sharing detection mode, thereby filtering out the influence of environmental interference on the battery protection system while reducing the overall power consumption of the battery protection system.

[0056] In one embodiment, if Figure 3As shown, the temperature detection circuit 30 also includes a second comparator 32; the anti-interference circuit 20 also includes a second delay circuit 23 and a second signal selection circuit 24; the first input end of the second comparator 32 is used to receive the second reference signal VTL, the second input end of the second comparator 32 is connected to the temperature detection end RTS, and is used to receive the target temperature signal of the temperature detection end RTS, the output end of the second comparator 32 is connected to the input end of the second delay circuit 23 and the first input end of the second signal selection circuit 24, and is used to output the temperature detection signal; the output end of the second delay circuit 23 is connected to the second input end of the second signal selection circuit 24, and is used to receive the temperature detection signal, and output the temperature detection signal after the first preset time; the control end and the output end of the second signal selection circuit 24 are connected to the timing protection circuit 10, and are used to switch to the third path when receiving the first timing signal, and the third path connects the second delay circuit 23 and the timing protection circuit 10; when receiving the second timing signal, it switches to the fourth path, and the fourth path connects the output end of the second comparator 32 and the timing protection circuit 10.

[0057] In the present embodiment, the temperature detection circuit 30 may further include a second comparator 32, and the anti-interference circuit 20 may further include a second delay circuit 23 and a second signal selection circuit 24. Among them, the working principles of the second comparator 32, the second delay circuit 23 and the second signal selection circuit 24 are similar to the working principles of the first comparator 31, the first delay circuit 21 and the first signal selection circuit 22, and are not repeated here. It should be noted that it is sufficient to ensure that the first comparator 31 and the second comparator 32 are used to compare different temperature detection signals. Preferably, the size of the first reference signal VTH is greater than the size of the second reference signal VTL. Thereby, the first comparator 31 can judge that the temperature is abnormal when the ambient temperature is high, and the second comparator 32 can judge that the temperature is abnormal when the ambient temperature is low, thereby detecting different ambient temperatures.

[0058] The first reference signal VTH and the second reference signal VTL can be generated by a reference circuit, and the specific circuit structure of the reference circuit can adopt the technology known to those skilled in the art, and it is sufficient to ensure that the magnitude of the first reference signal VTH is greater than the magnitude of the second reference signal VTL. Exemplarily, the first reference signal VTH is a first reference voltage, and the second reference signal VTL is a second reference voltage.

[0059] As an example, the first signal selection circuit 22 and the second signal selection circuit 24 are MUX (Multiplexer, MUX for short) circuits.

[0060] In one embodiment, if Figure 4As shown, the battery protection circuit also includes a logic control circuit 50; the timing protection circuit 10 is also used to output a temperature alarm signal after a second preset time when there is a temperature abnormality; the logic control circuit 50 is connected to the timing protection circuit 10, and is used to receive the temperature alarm signal and enter the temperature protection mode.

[0061] As an example, the second preset time may be selected based on actual experience.

[0062] In this embodiment, the timing protection circuit 10 outputs a temperature alarm signal when there is a temperature abnormality and after a second preset time, so that the logic control circuit 50 enters a temperature protection mode after receiving the temperature alarm signal, thereby improving the safety of the battery protection system. Exemplarily, the temperature protection mode can be a working mode that cuts off the charge and discharge circuit of the battery.

[0063] This embodiment provides a battery protection chip 1, comprising the above-mentioned battery protection circuit.

[0064] This embodiment provides a battery protection system, including the battery protection chip 1 mentioned above.

[0065] In one embodiment, the battery protection system also includes a first resistor and a thermistor; the first resistor and the thermistor are connected in series between the power terminal RTV and the ground terminal, and the connection node between the first resistor and the thermistor is connected to the temperature detection terminal RTS of the battery protection chip 1.

[0066] In this embodiment, if Figure 4 As shown, when the timing protection circuit 10 determines that there is no temperature anomaly, the first comparator 31 and the second comparator 32 both output low levels, and the timing protection circuit 10 outputs the second timing signal (low level), so that the first signal selection circuit 22 selects the second path, and the second signal selection circuit 24 selects the fourth path, and outputs the temperature detection signal to the timing protection circuit 10. .

[0067] like Figure 4 As shown, when the timing protection circuit 10 determines that there is a temperature anomaly, the timing protection circuit 10 outputs the first timing signal (high level) to continuously enable the temperature detection circuit 30, so that the temperature detection circuit 30 enters the real-time detection mode, and at the same time, the first signal selection circuit 22 selects the first path, and the output target electrical signal after a delay of 10ms is sent to the timing protection circuit 10 through the first delay circuit 21. That is, when the temperature is abnormal, the temperature detection circuit 30 will automatically switch to real-time detection, and filter the temperature detection signal for 10ms. If the first comparator 31 flips within 10ms, the first delay circuit 21 will reset, thereby resetting the timing protection circuit 10, and will not output a temperature alarm signal to the logic control circuit 50. Figure 5It is a special waveform display of the above embodiment. RTV is the power supply terminal RTV, and RTS is the temperature detection terminal RTS.

[0068] The first delay circuit 21 can filter out the power frequency interference. The waveform of the special case is shown as follows. Figure 6 When the ambient temperature is less than the first reference signal VTH and there is no power frequency interference, the temperature detection signal of the temperature detection terminal RTS is greater than the first reference signal VTH. However, due to the power frequency interference, the temperature detection terminal RTS will have a temperature detection signal less than the first reference signal VTH, resulting in a misjudgment of a temperature anomaly. The timing protection circuit 10 outputs a first timing signal, controls the temperature detection circuit 30 to enter the real-time detection mode, and controls the first signal selection circuit 22 in the anti-interference circuit 20 to select the first path. The first delay circuit 21 inputs the target electrical signal after 10ms filtering to the timing protection circuit 10. The power frequency interference is generated on the basis of the DC quantity of the temperature detection terminal RTS. It is known from the symmetry that the part of the target detection signal less than the first reference signal VTH after the power frequency interference is applied is less than half a cycle, that is, 10ms, that is, the time when the first comparator 31 outputs a high level (detecting the presence of temperature anomaly) is less than 10ms. The temperature detection signal less than 10ms is filtered out by the first delay circuit 21, so that the timing protection circuit 10 is reset, and the second timing signal is output, and the temperature alarm signal will not be output to the logic control circuit 50, avoiding false protection.

[0069] It should be noted that Figure 5 and Figure 6 The working principles of the first comparator 31, the first delay circuit 21 and the first signal selection circuit 22 are used as examples for explanation. The working principles of the second comparator 32, the second delay circuit 23 and the second signal selection circuit 24 are similar and will not be repeated here.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A battery protection circuit, characterized in that: Including timing protection circuit, anti-interference circuit and temperature detection circuit; The temperature detection circuit is connected to the temperature detection terminal and is used to output a temperature detection signal; The anti-interference circuit is connected to the timing protection circuit and the temperature detection circuit, and is used to enter a delayed output mode according to a first timing signal output by the timing protection circuit, or to enter a real-time output mode according to a second timing signal output by the timing protection circuit, process the temperature detection signal, and output a target electrical signal; The timing protection circuit is used to determine whether there is a temperature abnormality according to the target electrical signal, and if there is a temperature abnormality, output the first timing signal to the anti-interference circuit; if there is no temperature abnormality, output the second timing signal to the anti-interference circuit; The temperature detection circuit is also connected to the timing protection circuit, and is used to enter the real-time detection mode and output the temperature detection signal when receiving the first timing signal; or enter the time-sharing detection mode when receiving the second timing signal.

2. The battery protection circuit according to claim 1, characterized in that: The battery protection circuit also includes a time-sharing control circuit; The time-sharing control circuit is connected to the temperature detection circuit and is used to output a time-sharing control signal to the temperature detection circuit; The temperature detection circuit is further configured to enter a time-sharing detection mode and output the temperature detection signal according to the time-sharing control signal when the second timing signal is received.

3. The battery protection circuit according to claim 1, characterized in that: The temperature detection circuit includes a first comparator; the anti-interference circuit includes a first delay circuit and a first signal selection circuit; The first input end of the first comparator is used to receive a first reference signal, the second input end of the first comparator is connected to the temperature detection end, and is used to receive a target temperature signal of the temperature detection end, and the output end of the first comparator is connected to the input end of the first delay circuit and the first input end of the first signal selection circuit, and is used to output the temperature detection signal; The output end of the first delay circuit is connected to the second input end of the first signal selection circuit, and is used to receive the temperature detection signal and output the temperature detection signal after a first preset time; The control end and the output end of the first signal selection circuit are connected to the timing protection circuit, and are used to switch to a first path when receiving the first timing signal, and the first path connects the first delay circuit and the timing protection circuit; when receiving the second timing signal, switch to a second path, and the second path connects the output end of the first comparator and the timing protection circuit.

4. The battery protection circuit according to claim 3, characterized in that: The temperature detection circuit also includes a second comparator; the anti-interference circuit also includes a second delay circuit and a second signal selection circuit; The first input terminal of the second comparator is used to receive the second reference signal, the second input terminal of the second comparator is connected to the temperature detection terminal, and is used to receive the target temperature signal of the temperature detection terminal, and the output terminal of the second comparator is connected to the input terminal of the second delay circuit and the first input terminal of the second signal selection circuit, and is used to output the temperature detection signal; The output end of the second delay circuit is connected to the second input end of the second signal selection circuit, and is used to receive the temperature detection signal and output the temperature detection signal after a first preset time; The control end and the output end of the second signal selection circuit are connected to the timing protection circuit, and are used to switch to a third path when receiving the first timing signal, and the third path connects the second delay circuit and the timing protection circuit; when receiving the second timing signal, switch to a fourth path, and the fourth path connects the output end of the second comparator and the timing protection circuit.

5. The battery protection circuit according to claim 4, characterized in that: The magnitude of the first reference signal is greater than the magnitude of the second reference signal.

6. The battery protection circuit according to claim 1, characterized in that: The battery protection circuit also includes a logic control circuit; The timing protection circuit is also used to output a temperature alarm signal after a second preset time when the temperature abnormality exists; The logic control circuit is connected to the timing protection circuit and is used to receive the temperature alarm signal and enter a temperature protection mode.

7. A battery protection chip, characterized in that: The invention comprises a battery protection circuit as claimed in any one of claims 1 to 6.

8. A battery protection system, characterized in that: Comprising the battery protection chip as described in claim 7.

9. The battery protection system according to claim 8, characterized in that: The battery protection system also includes a first resistor and a thermistor; The first resistor and the thermistor are connected in series between a power supply terminal and a ground terminal, and a connection node between the first resistor and the thermistor is connected to a temperature detection terminal of the battery protection chip.

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