CN113410894A - Battery protection circuit and method - Google Patents

Abstract

The application relates to a battery protection circuit and a method, belonging to the technical field of battery protection, wherein the battery protection circuit comprises a voltage detection circuit, a current detection circuit and a low-power consumption logic control circuit, wherein the current detection circuit comprises an overcurrent detection sub-circuit; the low-power-consumption logic control circuit is respectively in communication connection with the voltage detection circuit and the over-current detection sub-circuit and is used for periodically outputting low-power-consumption logic control signals so as to control the voltage detection circuit and the over-current detection sub-circuit to periodically work. Because the low-power-consumption logic control circuit periodically outputs the low-power-consumption logic control signal, the voltage detection circuit and the over-current detection sub-circuit are controlled by the low-power-consumption logic control signal to periodically work, and the voltage detection circuit and the over-current detection sub-circuit are not required to continuously work, the electric quantity of the battery consumed by the battery protection chip when the battery is protected is reduced, and the service life of the battery is prolonged.

Description

Battery protection circuit and method

Technical Field

The present application relates to the field of battery protection technologies, and in particular, to a battery protection circuit and method.

Background

In mobile and wearable devices, the standby current of the electronics used should be as low as possible to extend the standby time of the mobile and wearable devices. Lithium batteries used in mobile devices require battery protection chips to protect the batteries from voltage or current anomalies.

Referring to fig. 1, in the related art, a lithium battery protection chip is disclosed, which includes a voltage detection circuit 110, a bandgap reference circuit 120, a current detection circuit 140, a driving circuit 130, and a power switch S; the voltage detection circuit 110 is connected to the VDD terminal and the driving circuit 130, respectively, for detecting the voltages at both ends of the battery; the driving circuit 130 is connected to the gate of the power switch S and is configured to control on/off of the power switch S; the source electrode of the power switch S is connected with the GND end, the drain electrode of the power switch S is connected with the VM end, and the power switch S is arranged in a battery charging and discharging circuit; the bandgap reference circuit 120 is respectively connected to the VDD terminal, the voltage detection circuit 110 and the current detection circuit 140 in a communication manner, and is configured to provide a voltage maximum threshold, a voltage minimum threshold and a reference current for the voltage detection circuit 110 and the current detection circuit 140; the current detection circuit 140 is respectively connected to the VDD terminal and the driving circuit 130, and is configured to detect a current for charging or discharging the battery; the positive electrode of the battery is connected with the VDD end, and the negative electrode of the battery is connected with the GND end; the load or charger is connected between the VDD terminal and the VM terminal.

When the battery is charged or discharged, the voltage detection circuit 110 detects voltages at two ends of the battery in real time, compares the detected voltage value with a voltage highest threshold and a voltage lowest threshold, and controls the power switch S to be turned off by the driving circuit 130 if the voltage value is higher than the voltage highest threshold or lower than the voltage lowest threshold, so that a battery charging or discharging loop is turned off; or the current detection circuit 140 detects the current for charging or discharging the battery in real time, compares the detected current value with a reference current value, and if the current value is greater than the reference current value, the driving circuit 130 controls the power switch S to be turned off, so that the battery charging or discharging loop is turned off; thereby protecting the battery.

In view of the above-mentioned related art, the inventor believes that since the voltage detection circuit 110 always detects the voltage across the battery in real time, the battery protection chip continuously consumes the electric quantity of the battery while protecting the battery, thereby reducing the service life of the battery.

Disclosure of Invention

In order to improve the service time of a battery, the application provides a battery protection circuit and a method.

In a first aspect, the present application provides a battery protection circuit, which adopts the following technical scheme:

a battery protection circuit comprises a voltage detection circuit, a current detection circuit and a low-power consumption logic control circuit, wherein the current detection circuit comprises an overcurrent detection sub-circuit; the low-power-consumption logic control circuit is respectively in communication connection with the voltage detection circuit and the over-current detection sub-circuit and is used for periodically outputting low-power-consumption logic control signals so as to control the voltage detection circuit and the over-current detection sub-circuit to periodically work.

By adopting the technical scheme, the low-power-consumption logic control circuit periodically outputs the low-power-consumption logic control signal, the voltage detection circuit and the over-current detection sub-circuit are controlled to periodically work through the low-power-consumption logic control signal, and the voltage detection circuit and the over-current detection sub-circuit are not required to continuously work, so that the electric quantity of the battery consumed by the battery protection chip when the battery is protected is reduced, and the service life of the battery is prolonged.

Optionally, the battery protection circuit further includes a bandgap reference circuit, and the low power consumption logic control circuit is in communication connection with the bandgap reference circuit and is configured to control the bandgap reference circuit to periodically operate.

By adopting the technical scheme, the purpose that the band gap reference circuit is controlled by the low-power-consumption logic control signal to work periodically is to further reduce the electric quantity of the battery consumed by the battery protection chip when the battery is protected.

Optionally, the current detection circuit includes a short-circuit detection sub-circuit, and the battery protection circuit further includes a sampling circuit, where the sampling circuit is respectively in communication connection with the bandgap reference circuit and the short-circuit detection sub-circuit, and is configured to collect a reference voltage provided by the bandgap reference circuit, so that the short-circuit detection sub-circuit can normally operate;

wherein the short detection sub-circuit operates continuously.

By adopting the technical scheme, the short circuit detection sub-circuit detects the current in the battery discharge loop so as to judge whether the battery discharge loop is short-circuited; because the short-circuit detection sub-circuit needs to work continuously in order to ensure that the battery protection circuit can detect the short-circuit state of the battery discharge loop fast enough, but because the band-gap reference circuit works periodically under a low-power logic control signal, the sampling circuit is arranged in order to make the short-circuit detection sub-circuit work continuously, when the band-gap reference circuit works, the sampling circuit collects and stores the reference voltage provided by the band-gap reference circuit, and when the band-gap reference circuit stops working, the sampling circuit provides the reference voltage for the short-circuit detection sub-circuit so as to make the short-circuit detection sub-circuit work normally.

Optionally, the low power consumption logic control circuit is in communication connection with the sampling circuit, and is configured to control the sampling circuit to periodically operate.

By sampling the technical scheme, the purpose of controlling the sampling circuit to periodically work through the low-power-consumption logic control signal is to further reduce the electric quantity of the battery consumed by the battery protection chip when the battery is protected.

Optionally, the low power consumption logic control circuit includes a low power consumption oscillator and a low power consumption control logic sub-circuit; the low-power consumption oscillator is in communication connection with the low-power consumption control logic sub-circuit; and the low-power consumption control logic sub-circuit is respectively in communication connection with the voltage detection circuit, the overcurrent detection sub-circuit, the band-gap reference circuit and the sampling circuit.

By adopting the technical scheme, the low-power-consumption control logic sub-circuit generates a low-power-consumption logic control signal, and the low-power-consumption oscillator enables the low-power-consumption logic control signal to be periodically output.

In a second aspect, the present application provides a battery protection method, which adopts the following technical scheme:

a battery protection method comprising the steps of:

periodically acquiring voltage values at two ends of the battery;

periodically acquiring a first current value of battery charging or discharging;

comparing the voltage value with a voltage highest threshold value and a voltage lowest threshold value, and if the voltage value is greater than the voltage highest threshold value or less than the voltage lowest threshold value, outputting a voltage abnormal signal;

comparing the first current value with a preset overcurrent threshold, and outputting a first current abnormal signal if the current value is greater than the overcurrent threshold;

and controlling the charging or discharging loop of the battery to be disconnected based on the voltage abnormal signal or the first current abnormal signal.

By adopting the technical scheme, the voltage values of the voltages at the two ends of the battery and the first current value of the charging or discharging of the battery are periodically obtained, so that whether the voltages at the two ends of the battery and the charging or discharging current of the battery are abnormal or not is judged, and the electric quantity of the battery consumed during the protection of the battery is reduced.

Optionally, the battery protection method further includes:

continuously acquiring a second current value of battery discharge;

comparing the second current value with a preset short-circuit current threshold, and outputting a second current abnormal signal if the second current value is greater than the short-circuit current threshold;

and controlling the discharge circuit of the battery to be disconnected based on the second current abnormal signal.

By adopting the technical scheme, the second current value is continuously obtained, so that the second current value is compared with the short-circuit current threshold value, the short-circuit state in the battery discharge loop can be detected quickly enough, and the battery is protected from being damaged.

Optionally, the step of controlling the charging or discharging circuit of the battery to be disconnected based on the voltage abnormality signal or the first current abnormality signal includes:

comparing the duration time of the voltage abnormal signal with a preset first time threshold, and if the duration time of the voltage abnormal signal is greater than the first time threshold, controlling a charging or discharging loop of the battery to be disconnected;

and comparing the duration time of the first current abnormal signal with a preset second time threshold, and if the duration time of the first current abnormal signal is greater than the second time threshold, controlling the charging or discharging loop of the battery to be disconnected.

By adopting the above technical scheme, the purpose of comparing the duration time of the voltage abnormal signal with the first time threshold value and the duration time of the first current abnormal signal with the second time threshold value is that, when the charging or discharging loop of the battery is controlled to be conducted, a transient large current or voltage may be generated in the charging or discharging loop of the battery, and therefore, in order to improve the accuracy of battery protection, the duration time of the voltage abnormal signal and the duration time of the first current abnormal signal need to be judged.

Optionally, the step of controlling the battery discharge circuit to be disconnected based on the second current abnormal signal includes:

comparing the duration time of the second current abnormal signal with a preset third time threshold, and if the duration time of the second current abnormal signal is greater than the third time threshold, controlling a discharging loop of the battery to be disconnected;

wherein the third time threshold is less than the second time threshold.

By adopting the technical scheme, because overlarge short-circuit current can be generated when the discharging loop of the battery is short-circuited, if the preset third time threshold is longer than the second time threshold, the short-circuit current can last for a long time, so that the battery is damaged, and the discharging loop of the battery needs to be disconnected quickly when the second current value is detected to be larger than the short-circuit current threshold.

In summary, the present application includes at least one of the following beneficial technical effects:

through the arrangement of the low-power-consumption logic control circuit, the low-power-consumption logic control circuit controls the voltage detection circuit and the over-current detection sub-circuit to periodically work, and the voltage detection circuit and the over-current detection sub-circuit do not need to continuously work, so that the electric quantity of the battery consumed by the battery protection chip when the battery is protected is reduced, and the service life of the battery is prolonged.

Drawings

Fig. 1 is a block diagram of a battery protection chip in the related art.

Fig. 2 is a block diagram of the battery protection circuit according to the present application.

FIG. 3 is a schematic diagram of a low power logic control signal.

Fig. 4 is a block diagram of a flow of determining whether a voltage is abnormal in the battery protection method.

Fig. 5 is a block diagram of a process for determining whether a current is over-current in a battery protection method.

Fig. 6 is a block diagram of a process for determining whether a battery charging or discharging circuit is short-circuited in a battery protection method.

Description of reference numerals: 110. a voltage detection circuit; 120. a bandgap reference circuit; 130. a drive circuit; 140. a current detection circuit; 141. an over-current detection sub-circuit; 142. a short circuit detection sub-circuit; 150. a low power consumption logic control circuit; 151. a low power consumption oscillator; 152. a low power consumption control logic sub-circuit; 160. a sampling circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The present application is described in further detail below with reference to figures 1-6.

Referring to fig. 1, in the related art, a lithium battery protection chip includes a voltage detection circuit 110, a bandgap reference circuit 120, a current detection circuit 140, a driving circuit 130, and a power switch S.

The voltage detection circuit 110 is respectively connected with the VDD terminal and the driving circuit 130; the driving circuit 130 is connected with the gate of the power switch S; the source of the power switch S is connected with the GND end, the drain thereof is connected with the VM end, and the power switch S is connected in series in a battery charging and discharging circuit; the bandgap reference circuit 120 is respectively connected to the VDD terminal, the voltage detection circuit 110 and the current detection circuit 140 in communication; the current detection circuit 140 is respectively connected to the VDD terminal and the driving circuit 130; the positive electrode of the battery is connected with the VDD end, and the negative electrode of the battery is connected with the GND end; the load or charger is connected between the VDD terminal and the VM terminal.

When the battery is charged or discharged, the voltage detection circuit 110 detects voltages at two ends of the battery in real time, compares the detected voltage value with a highest voltage threshold and a lowest voltage threshold provided by the bandgap reference circuit 120, and if the voltage value is higher than the highest voltage threshold or lower than the lowest voltage threshold, the driving circuit 130 controls the power switch S to be turned off, so that the battery charging or discharging loop is turned off; or, the current detection circuit 140 detects the current for charging or discharging the battery in real time, compares the detected current value with the reference current value provided by the bandgap reference circuit 120, and if the current value is greater than the reference current value, the driving circuit 130 controls the power switch S to be turned off, so as to turn off the battery charging or discharging loop; thereby protecting the battery.

Because the battery protection chip is in a real-time working state, the electric quantity of the battery can be consumed when an internal circuit works; therefore, in order to reduce the amount of power consumed while the battery is protected;

referring to fig. 2, an embodiment of the present application provides a battery protection circuit, which may include a low power logic control circuit 150, where the low power logic control circuit 150 is communicatively connected to the voltage detection circuit 110. The current detection circuit 140 includes an over-current detection sub-circuit 141, and the low power consumption logic control circuit 150 is further connected to the over-current detection sub-circuit 141 in communication.

When the battery is charged or discharged, the low power consumption logic control circuit 150 periodically outputs a low power consumption logic control signal, which controls the voltage detection circuit 110 and the over-current detection sub-circuit 141 to periodically operate, so as to reduce the amount of power of the battery consumed when the battery protection chip protects the battery.

To further reduce the amount of power consumed by the battery, the low power logic control circuit 150 is also communicatively coupled to the bandgap reference circuit 120 for controlling the bandgap reference circuit 120 to operate periodically.

To ensure that the battery protection circuit can detect the short circuit condition of the battery discharge circuit fast enough, the current detection circuit 140 further includes a short detection sub-circuit 142, and the short detection sub-circuit 142 continues to operate; the bandgap reference circuit 120 provides a reference voltage for the short detection sub-circuit 142 to keep the short detection sub-circuit 142 operating.

However, since the bandgap reference circuit 120 operates periodically, in order to keep the short circuit detection sub-circuit 142 operating continuously, the battery protection circuit further includes a sampling circuit 160, and the sampling circuit 160 is communicatively connected to the bandgap reference circuit 120 and the short circuit detection sub-circuit 142, respectively. The low power logic control circuit 150 is communicatively connected to the sampling circuit 160, and controls the sampling circuit 160 to operate periodically.

When the bandgap reference circuit 120 is operating, the sampling circuit 160 is operating, and the sampling circuit 160 samples and stores the reference voltage provided by the bandgap reference circuit 120, and when the bandgap reference circuit 120 is not operating, the sampling circuit 160 provides the reference voltage for the short detection sub-circuit 142.

The low power consumption logic control circuit 150 includes a low power consumption oscillator 151 and a low power consumption control logic sub-circuit 152; the low power oscillator 151 is communicatively coupled to the low power control logic sub-circuit 152 such that the low power control logic sub-circuit 152 periodically outputs the low power control logic signal. Wherein, the low power consumption means that the voltage is in the range of 2.8V-4.2V when the power supply works.

In addition, referring to fig. 3, a low power consumption logic control signal is built as follows:

the voltage detection circuit 110, the overcurrent detection sub-circuit 141, the band-gap reference circuit 120 and the sampling circuit 160 are operated as a high level, and the high level is effective; that is, when the bandgap reference circuit 120 operates, the bandgap reference enable signal is at a high level; when the over-current detection sub-circuit 141 and the voltage detection module work, the detection enable signal is at a high level; the sampling circuit 160 is operative to sample the enable signal high. In other embodiments, the circuit operation state may be set to low level, and the low level may be active, specifically, set manually, and the circuit required for the low power consumption logic control signal control may be periodically operated.

Setting the low power consumption logic control signal to be 20ms as a control period, wherein the bandgap reference circuit 120 works for 4ms within 20 ms; the over-current detection sub-circuit 141, the voltage detection circuit 110 and the sampling circuit 160 work simultaneously, and after the band-gap reference circuit 120 works for 2ms, the over-current detection sub-circuit 141, the voltage detection circuit 110 and the sampling circuit 160 work again; the bandgap reference circuit 120 stops operating after 4ms, and the over-current detection sub-circuit 141, the voltage detection circuit 110 and the sampling circuit 160 stop operating 5us earlier than the bandgap reference circuit 120.

The purpose of turning on the bandgap reference circuit 120 in advance is to ensure that the reference voltage and the reference current provided by the bandgap reference circuit 120 are correctly established when the bandgap reference circuit operates; the purpose of finally turning off the bandgap reference circuit 120 is to prevent occurrence of random sequences, which may cause unexpected situations, thereby improving the overall stability of the battery protection circuit.

In addition, if the voltage across the battery or the charging or discharging current of the battery is in an abnormal state, the low power consumption logic control signal controls the bandgap reference circuit 120, the over-current detection sub-circuit 141, the voltage detection circuit 110 and the sampling circuit 160 to keep on, and at this time, the driving circuit 130 controls the power switch S to be turned off until the battery protection circuit returns to normal.

The principle of the embodiment is as follows:

when the battery is charged or discharged, the short-circuit detection sub-circuit 142, the driving circuit 130, the low-power-consumption oscillator 151 and the low-power-consumption control logic sub-circuit 152 are started, then the low-power-consumption control logic sub-circuit 152 firstly controls the band-gap reference circuit 120 to be started, and after the band-gap reference circuit 120 is started for 2ms, the voltage detection circuit 110, the over-current detection sub-circuit 141 and the sampling circuit 160 are controlled to be started simultaneously;

the voltage detection circuit 110 detects the voltage at two ends of the battery, the overcurrent detection sub-circuit 141 detects the current in the battery charging or discharging loop, the short-circuit detection sub-circuit 142 detects the current in the battery discharging loop, if the voltage is normal and/or the current is normal, the low-power consumption control logic sub-circuit 152 controls the band-gap reference circuit 120 to be opened for 4ms and then closed, and controls the voltage detection circuit 110, the overcurrent detection sub-circuit 141 and the sampling circuit 160 to be closed 5us ahead of the band-gap reference circuit 120; after 20ms, the low power consumption control logic sub-circuit 152 turns on the bandgap reference circuit 120 again, so that the bandgap reference circuit 120, the voltage detection circuit 110, the over-current detection sub-circuit 141 and the sampling circuit 160 work periodically;

if the voltage detection circuit 110 detects that the voltage value at the two ends of the battery is greater than the highest voltage threshold or less than the lowest voltage threshold, or the overcurrent detection sub-circuit 141 detects that the current value of the battery for charging or discharging is greater than the overcurrent threshold or the short-circuit detection sub-circuit 142 detects that the current value of the battery for discharging is greater than the short-circuit current threshold, the low-power consumption control logic sub-circuit 152 controls the bandgap reference circuit 120, the voltage detection circuit 110, the overcurrent detection sub-circuit 141 and the sampling circuit 160 to keep working, so that the driving circuit 130 controls the power switch S to be turned off, so that the charging or discharging loop of the battery is turned off until the battery protection circuit returns to normal.

Referring to fig. 4 and 5, based on the embodiment of the battery protection circuit, the second embodiment of the present application further provides a battery protection method, which may include the following steps S101 to S106 as an implementation manner of the battery protection method:

s101, periodically acquiring voltage values at two ends of a battery;

wherein, the voltage detection circuit 110 is controlled by the low power consumption control logic sub-circuit 152 to periodically obtain the voltage value at two ends of the battery.

S102, periodically acquiring a first current value of battery charging or discharging;

wherein, the low power consumption control logic sub-circuit 152 controls the over-current detection sub-circuit 141 to periodically obtain the first current value for charging or discharging the battery.

S103, comparing the voltage value with a highest voltage threshold and a lowest voltage threshold, and outputting a voltage abnormal signal if the voltage value is greater than the highest voltage threshold or smaller than the lowest voltage threshold;

for example, the maximum voltage is set to 4.28V, and the minimum voltage is set to 2.8V; if the voltage detection circuit 110 detects that the voltage value of the battery voltage is 4.3V, 4.3V >4.28V, or if the voltage detection circuit 110 detects that the voltage of the battery is 2.6V, 2.6V <2.8V, the voltage detection circuit 110 will output a voltage abnormality signal.

S104, comparing the duration time of the voltage abnormal signal with a preset first time threshold, and if the duration time of the voltage abnormal signal is greater than the first time threshold, controlling the disconnection of a charging or discharging loop of the battery;

after receiving the voltage abnormal signal, the driving circuit 130 determines the duration of the voltage abnormal signal, and controls the power switch S to be turned off if the duration of the voltage abnormal signal is greater than the first time threshold, so as to control the battery charging or discharging circuit to be turned off.

For example, the first time threshold is set to 200ms, and if the voltage abnormality signal continues to exist within 300ms, the driving circuit 130 controls the power switch S to be turned off at this time for 300ms >200 ms.

S105, comparing the first current value with a preset overcurrent threshold, and outputting a first current abnormal signal if the current value is greater than the overcurrent threshold;

wherein, the over-current threshold is a reference current provided by the bandgap reference circuit 120.

For example, the overcurrent threshold is set to 2A; if the over-current detection sub-circuit 141 detects that the current value of the battery charging or discharging is 3A, 3A >2A, the over-current detection sub-circuit 141 outputs a first current abnormal signal.

S106, comparing the duration time of the first current abnormal signal with a preset second time threshold, and if the duration time of the first current abnormal signal is greater than the second time threshold, controlling a charging or discharging loop of the battery to be disconnected;

after receiving the first current abnormal signal, the driving circuit 130 determines the duration of the first current abnormal signal, and controls the power switch S to be turned off if the duration of the first current abnormal signal is greater than the second time threshold, so as to control the battery charging or discharging circuit to be turned off.

For example, the second time threshold is set to 50ms, and if the first current abnormal signal is continuously present within 60ms, at this time, 60ms >50ms, the driving circuit 130 controls the power switch S to be turned off.

Referring to fig. 6, in order to ensure that a short circuit condition in the charge or discharge circuit of the battery can be detected fast enough, thereby protecting the battery from damage; the battery protection method may further include steps S201 to S203:

s201, continuously acquiring a second current value of battery discharge;

wherein the short detection sub-circuit 142 continues to operate.

S202, comparing the second current value with a preset short-circuit current threshold, and outputting a second current abnormal signal if the second current value is greater than the short-circuit current threshold;

for example, the short-circuit current threshold is set to 4A; if the short-circuit detection sub-circuit 142 detects that the current value of the battery discharge current is 5A, and 5A is greater than 4A, the short-circuit detection sub-circuit 142 outputs a second current abnormal signal;

s203, comparing the duration time of the second current abnormal signal with a preset third time threshold, and if the duration time of the second current abnormal signal is greater than the third time threshold, controlling the battery discharge loop to be disconnected;

after receiving the second current abnormal signal, the driving circuit 130 determines the duration of the second current abnormal signal, and controls the power switch S to be turned off if the duration of the second current abnormal signal is greater than a third time threshold, so as to control the battery discharge circuit to be turned off. It should be noted that the third time threshold is smaller than the second time threshold.

For example, the third time threshold is set to 200us, and if the second current abnormality signal continues to exist for 300us, and 300us >200us at this time, the drive circuit 130 controls the power switch S to be turned off.

The implementation principle of the embodiment is as follows:

when the battery is charged or discharged, periodically acquiring the voltage at two ends of the battery, periodically acquiring a first current value of the battery for charging or discharging, and continuously acquiring a second current value of the battery for charging or discharging;

comparing the voltage value with a voltage highest threshold value and a voltage lowest threshold value, and outputting a voltage abnormal signal if the voltage value is greater than the voltage highest threshold value or less than the voltage lowest threshold value; if the duration of the voltage abnormal signal is greater than a first time threshold, controlling a battery charging or discharging loop to be disconnected;

comparing the first current value with an overcurrent threshold value, and outputting a first current abnormal signal if the first current value is greater than the overcurrent threshold value; if the duration of the first current abnormal signal is greater than a second time threshold, controlling the battery charging or discharging loop to be disconnected;

comparing the second current value with the short-circuit current threshold, and outputting a second current abnormal signal if the second current value is greater than the short-circuit current threshold; and if the duration of the second current abnormal signal is greater than a third time threshold, controlling the battery discharge loop to be disconnected.

The foregoing is a preferred embodiment in its own right and not intended to limit the scope of the application, and any feature disclosed in this specification (including the abstract and drawings) may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

Claims (9)

1. A battery protection circuit comprises a voltage detection circuit (110) and a current detection circuit (140), and is characterized by further comprising a low-power consumption logic control circuit (150), wherein the current detection circuit (140) comprises an overcurrent detection sub-circuit (141); the low-power-consumption logic control circuit (150) is respectively in communication connection with the voltage detection circuit (110) and the overcurrent detection sub-circuit (141) and is used for periodically outputting low-power-consumption logic control signals so as to control the voltage detection circuit (110) and the overcurrent detection sub-circuit (141) to periodically work.

2. The battery protection circuit of claim 1, further comprising a bandgap reference circuit (120), wherein the low power logic control circuit (150) is communicatively coupled to the bandgap reference circuit (120) for controlling the bandgap reference circuit (120) to operate periodically.

3. The battery protection circuit according to claim 2, wherein the current detection circuit (140) comprises a short-circuit detection sub-circuit (142), the battery protection circuit further comprises a sampling circuit (160), and the sampling circuit (160) is respectively connected to the bandgap reference circuit (120) and the short-circuit detection sub-circuit (142) in a communication manner, and is configured to collect a reference voltage provided by the bandgap reference circuit (120) for the short-circuit detection sub-circuit (142) to operate normally;

wherein the short detection subcircuit (142) operates continuously.

4. The battery protection circuit of claim 3, wherein the low power logic control circuit (150) is communicatively coupled to the sampling circuit (160) for controlling the sampling circuit (160) to operate periodically.

5. The battery protection circuit according to any of claims 1-4, wherein the low power consumption logic control circuit (150) comprises a low power consumption oscillator (151) and a low power consumption control logic sub-circuit (152); the low power oscillator (151) is communicatively coupled to the low power control logic subcircuit (152); the low-power consumption control logic sub-circuit (152) is respectively in communication connection with the voltage detection circuit (110), the overcurrent detection sub-circuit (141), the band-gap reference circuit (120) and the sampling circuit (160).

6. A battery protection method comprising the steps of:

periodically acquiring voltage values at two ends of the battery;

periodically acquiring a first current value of battery charging or discharging;

comparing the voltage value with a voltage highest threshold value and a voltage lowest threshold value, and if the voltage value is greater than the voltage highest threshold value or less than the voltage lowest threshold value, outputting a voltage abnormal signal;

comparing the first current value with a preset overcurrent threshold, and outputting a first current abnormal signal if the current value is greater than the overcurrent threshold;

and controlling the charging or discharging loop of the battery to be disconnected based on the voltage abnormal signal or the first current abnormal signal.

7. The battery protection method according to claim 6, further comprising:

continuously acquiring a second current value of battery discharge;

comparing the second current value with a preset short-circuit current threshold, and outputting a second current abnormal signal if the second current value is greater than the short-circuit current threshold;

and controlling the discharge circuit of the battery to be disconnected based on the second current abnormal signal.

8. The battery protection method according to claim 6, wherein the step of controlling the charging or discharging circuit of the battery before the disconnection based on the voltage abnormality signal or the first current abnormality signal comprises:

comparing the duration time of the voltage abnormal signal with a preset first time threshold, and if the duration time of the voltage abnormal signal is greater than the first time threshold, controlling a charging or discharging loop of the battery to be disconnected;

and comparing the duration time of the first current abnormal signal with a preset second time threshold, and if the duration time of the first current abnormal signal is greater than the second time threshold, controlling the charging or discharging loop of the battery to be disconnected.

9. The battery protection method according to claim 7, wherein the step of controlling before the battery discharge circuit is opened based on the second current abnormality signal includes:

comparing the duration time of the second current abnormal signal with a preset third time threshold, and if the duration time of the second current abnormal signal is greater than the third time threshold, controlling a discharging loop of the battery to be disconnected;

wherein the third time threshold is less than the second time threshold.

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