Temperature protection circuit, chip, charge and discharge control circuit, system and module

Abstract

The utility model discloses a temperature protection circuit, a chip, a charge and discharge control circuit, a system and a module. The temperature protection circuit comprises a switchable resistance circuit, wherein the first end of the switchable resistance circuit is connected with a power supply input end, and the second end is used for connecting a thermistor circuit; the first end of the reference adjustment circuit is connected with a power input end, the second end is grounded, the third end is used for outputting a reference voltage signal, and the control end is used for receiving a reference adjustment signal; a first input end of the comparator is connected with a third end of the reference adjustment circuit and is used for receiving a reference voltage signal; the second input end is connected with the second end of the switchable resistance circuit and the thermistor circuit and is used for receiving a temperature signal; the output end of the comparator is used for outputting a temperature protection signal according to the temperature signal and the reference voltage signal. According to the technical scheme, the temperature protection threshold value of the temperature protection circuit is flexibly adjusted through the switchable resistance circuit, temperature hysteresis protection is carried out through the reference adjustment circuit, and the reliability of the temperature protection circuit is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a temperature protection circuit, chip, charge and discharge control circuit, system and module. BACKGROUND

[0002] In the use process of lithium battery, the environmental temperature is a very important safety hazard to lithium battery, for the safety consideration, most battery protection chips are equipped with temperature detection function. There are some technologies that can collect the environmental temperature of lithium battery in the prior art, but most of these technologies have low detection sensitivity, complex circuit, and inconvenient temperature protection threshold adjustment, and cannot be adjusted simply and conveniently, and the resistance value needs to be replaced each time, which is troublesome and has low sensitivity. INVENTION CONTENTS

[0003] The utility model embodiment provides a temperature protection circuit, chip, charge and discharge control circuit, system and module to solve the problem that the temperature protection threshold of the prior art temperature protection circuit cannot be flexibly adjusted.

[0004] A temperature protection circuit, comprising a switchable resistance circuit, a reference adjustment circuit and a comparator:

[0005] The first end of the switchable resistance circuit is connected with the power input end, and the second end of the switchable resistance circuit is used for connecting a thermistor circuit.

[0006] The first end of the reference adjustment circuit is used for connecting the power input end, the second end of the reference adjustment circuit is grounded, the third end of the reference adjustment circuit is used for outputting a reference voltage signal, and the control end of the reference adjustment circuit is used for receiving a reference adjustment signal.

[0007] The first input end of the comparator is connected with the third end of the reference adjustment circuit, for receiving the reference voltage signal; the second input end of the comparator is connected with the second end of the switchable resistance circuit and the thermistor circuit, for receiving a temperature signal; and the output end of the comparator is used for outputting a temperature protection signal according to the temperature signal and the reference voltage signal.

[0008] Further, the switchable resistance circuit comprises N first resistors and N bypass circuits, and N≥2.

[0009] The N first resistors are connected in series between the power input end and the thermistor circuit.

[0010] Each first resistor is connected in parallel with a bypass circuit.

[0011] Further, the bypass circuit comprises a fuse.

[0012] Further, the reference adjustment circuit comprises a first resistance circuit, a second resistance circuit, a third resistance circuit, a first switch tube and a second switch tube;

[0013] The first resistance circuit, the second resistance circuit and the third resistance circuit are sequentially connected in series between the power input end and the ground;

[0014] The first end of the first switch tube is connected with the first resistance circuit and the second resistance circuit, the second end of the first switch tube is connected with the first input end of the comparator, and the third end of the first switch tube is used for receiving a first reference adjustment signal;

[0015] The first end of the second switch tube is connected with the second resistance circuit and the third resistance circuit, the second end of the second switch tube is connected with the first input end of the comparator, and the third end of the second switch tube is used for receiving a second reference adjustment signal.

[0016] Further, the temperature protection circuit further comprises a third switch tube;

[0017] The first end of the third switch tube is used for connecting the power input end, the second end of the third switch tube is connected with the first end of the switchable resistance circuit and the first end of the reference adjustment circuit, and the third end of the third switch tube is used for receiving a first clock signal.

[0018] Further, the temperature protection circuit further comprises a D flip-flop;

[0019] The first input end of the D flip-flop is connected with the output end of the comparator, the second input end of the D flip-flop is used for receiving a second clock signal, and the output end of the D flip-flop is used for outputting the temperature protection signal.

[0020] A battery protection chip comprises a logic control circuit and the temperature protection circuit described above;

[0021] The temperature protection circuit is connected with the logic control circuit and is used for outputting a temperature protection signal to the logic control circuit;

[0022] The logic control circuit is used for connecting a charge-discharge switch circuit and is used for controlling the charge-discharge switch circuit to work according to the temperature protection signal.

[0023] A charge-discharge control circuit comprises a thermistor circuit, a charge-discharge switch circuit and the battery protection chip described above;

[0024] The thermistor circuit is used for detecting an ambient temperature;

[0025] The charge-discharge switch circuit is used for connecting a battery and a charge-discharge connection end.

[0026] The temperature protection circuit is connected with the thermistor circuit, and the logic control circuit is connected with the charge-discharge switch circuit.

[0027] A charge-discharge control system comprises a battery and the charge-discharge control circuit.

[0028] The battery is connected with the charge-discharge control circuit.

[0029] A battery module comprises the charge-discharge control system.

[0030] The utility model embodiment provides temperature protection circuit, chip, charge -discharge control circuit, system and module, temperature protection circuit includes switchable resistance circuit, reference adjustment circuit and comparator: through connecting the first end of switchable resistance circuit with power input end, the second end of switchable resistance circuit is used for connecting thermistor circuit;The first end of reference adjustment circuit is used for connecting power input end, and the second end of reference adjustment circuit is grounded, and the third end of reference adjustment circuit is used for outputting reference voltage signal, and the control end of reference adjustment circuit is used for receiving reference adjustment signal;The first input end of comparator is connected with the third end of reference adjustment circuit, and is used for receiving reference voltage signal;The second input end of comparator is connected with the second end of switchable resistance circuit and thermistor circuit, and is used for receiving temperature signal;The output end of comparator is used for outputting temperature protection signal according to temperature signal and reference voltage signal, so as to adjust the temperature protection threshold of temperature protection circuit flexibly through switchable resistance circuit, and temperature hysteresis protection is carried out through reference adjustment circuit, and the reliability of temperature protection circuit is improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical scheme of the utility model embodiment, the following will be briefly introduced the drawings needed to be used in the description of the utility model embodiment, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without the creative labor.

[0032] Figure 1 It is a schematic diagram of temperature protection circuit in the utility model embodiment;

[0033] Figure 2 It is a schematic diagram of charge-discharge control system in the utility model embodiment.

[0034] In the figure: 1, battery; 2, charge and discharge control circuit; 21, thermistor circuit; 22, charge and discharge switch circuit; 23, battery protection chip; 231, logic control circuit; 232, temperature protection circuit; 2321, switchable resistance circuit; 232a, N first resistors; 232b, N bypass circuits; 2322, reference adjustment circuit; 232c, first resistance circuit; 232d, second resistance circuit; 232e, third resistance circuit; 2323, comparator; 2324, D flip-flop. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] It should be understood that the present application can be implemented in different forms and should not be interpreted as being limited to the embodiments presented herein. On the contrary, these embodiments are presented in order to provide a thorough and complete disclosure and to convey the full scope of the present application to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions can be exaggerated for clarity throughout the drawings the same reference numerals designate the same elements.

[0037] It should be understood that when an element or layer is referred to as being "on", "adjacent", "connected to", or "coupled to" another element or layer, it can be directly on, adjacent, connected or coupled to the other element or layer, or an intervening element or layer can be present. In contrast, when an element is referred to as being "directly on", "directly adjacent", "directly connected to", or "directly coupled to" another element or layer, then there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

[0038] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and / or operation in addition to the orientations depicted in the figures. For example, if a device in the figures is inverted, then a dependent element or feature described as "below" or "beneath" another element or feature would then be oriented "above" and / or "over" the other element or feature. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0039] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] For a thorough understanding of the present application, reference should be made to the following detailed description, in conjunction with the accompanying drawings, in which:

[0041] The present embodiment provides a temperature protection circuit 232 applied in a battery protection chip 23. Exemplarily, the battery protection chip 23 is applied in a charge-discharge control circuit 2. Alternatively, as shown in FIG. 1, the charge-discharge control circuit 2 comprises a thermistor circuit 21, a charge-discharge switch circuit 22 and the battery protection chip 23; the thermistor circuit 21 is used for detecting ambient temperature; the charge-discharge switch circuit 22 is used for connecting the battery 1 and a charge-discharge connection end; the temperature protection circuit 232 is connected with the thermistor circuit 21, and the logic control circuit 231 is connected with the charge-discharge switch circuit 22. Figure 2

[0042] The battery 1 can be a battery pack. The battery 1 pack comprises at least one battery cell. Alternatively, the battery cell is a lithium ion battery cell. The charge-discharge connection end is used for connecting a load or a charging device. Exemplarily, the charging device can be a charger or a power storage device.

[0043] ​As an example, the thermistor circuit 21 comprises a thermistor. As preferred, the thermistor is a negative temperature coefficient thermistor. Optionally, the thermistor circuit 21 can comprise one thermistor or a plurality of thermistors. The plurality of thermistors can be arranged in series and / or in parallel. It can be understood that the number, arrangement and resistance value of the thermistors can be set according to actual experience and requirements, which are not limited herein. The thermistor circuit 21 can be arranged in the product interior according to actual requirements, for collecting the ambient temperature of the product interior battery 1.

[0044] As an example, the charge-discharge switch circuit 22 comprises a charge switch tube and a discharge switch tube. As an example, the charge switch tube and the discharge switch tube can both be MOS tubes. As an example, the charge switch tube and the discharge switch tube are arranged in series between the battery 1 and the charge-discharge connection end, and the control end of the charge switch tube and the control end of the discharge switch tube are respectively connected to the charge control end and the discharge control end of the battery protection chip 23.

[0045] The embodiment provides a temperature protection circuit 232, comprising a switchable resistance circuit 2321, a reference adjustment circuit 2322 and a comparator 2323: a first end of the switchable resistance circuit 2321 is connected to a power input end, and a second end of the switchable resistance circuit 2321 is used for connecting the thermistor circuit 21; a first end of the reference adjustment circuit 2322 is used for connecting the power input end, a second end of the reference adjustment circuit 2322 is grounded, a third end of the reference adjustment circuit 2322 is used for outputting a reference voltage signal, and a control end of the reference adjustment circuit 2322 is used for receiving a reference adjustment signal; a first input end of the comparator 2323 is connected to the third end of the reference adjustment circuit 2322, for receiving the reference voltage signal; a second input end of the comparator 2323 is connected to the second end of the switchable resistance circuit 2321 and the thermistor circuit 21, for receiving a temperature signal; and an output end of the comparator 2323 is used for outputting a temperature protection signal according to the temperature signal and the reference voltage signal.

[0046] As an example, a first end of the switchable resistance circuit 2321 is connected to the power input end, and a second end of the switchable resistance circuit 2321 is used for connecting the thermistor circuit 21, so as to adjust the resistance voltage division ratio between the switchable resistance circuit 2321 and the thermistor circuit 21 through the resistance value of the switchable resistance circuit 2321, and further adjust the temperature protection threshold of the temperature protection circuit 232.

[0047] As an example, the first end of the reference adjustment circuit 2322 is connected to a power input end, the second end of the reference adjustment circuit 2322 is grounded, the third end of the reference adjustment circuit 2322 is used to output a reference voltage signal, and the control end of the reference adjustment circuit 2322 is used to receive a reference adjustment signal. In this example, by configuring a suitable reference adjustment signal, the upper limit value and the lower limit value of the reference voltage signal are adjusted, and then the upper limit temperature and the lower limit temperature of the temperature protection circuit 232 are adjusted, so as to realize temperature protection hysteresis, ensure that the temperature protection circuit 232 does not frequently trigger protection when the temperature fluctuation is small, and enhance the stability of the system.

[0048] As an example, the first input end of the comparator 2323 is connected to the third end of the reference adjustment circuit 2322, used to receive the reference voltage signal; the second input end of the comparator 2323 is connected to the second end of the switchable resistance circuit 2321 and the thermistor circuit 21, used to receive the temperature signal; and the output end of the comparator 2323 is used to output a temperature protection signal according to the temperature signal and the reference voltage signal, so that when the comparator 2323 judges that the voltage value corresponding to the temperature signal is greater than the voltage value corresponding to the reference voltage signal, it is determined that the temperature is too high, and the temperature protection signal is output. Illustratively, the output end of the comparator 2323 is connected to the logic control circuit 231 of the battery protection chip 23, and the logic control circuit 231 is used to connect the charge-discharge switching circuit 22 and control the charge-discharge switching circuit 22 to work according to the temperature protection signal. Thus, when the temperature is too high, the charge-discharge switching circuit 22 is controlled to be turned off by the logic control circuit 231, and circuit protection is performed.

[0049] In this embodiment, the temperature protection circuit 232 includes a switchable resistance circuit 2321, a reference adjustment circuit 2322, and a comparator 2323: the first end of the switchable resistance circuit 2321 is connected to a power input end, and the second end of the switchable resistance circuit 2321 is used to connect the thermistor circuit 21; the first end of the reference adjustment circuit 2322 is connected to a power input end, the second end of the reference adjustment circuit 2322 is grounded, the third end of the reference adjustment circuit 2322 is used to output a reference voltage signal, and the control end of the reference adjustment circuit 2322 is used to receive a reference adjustment signal; the first input end of the comparator 2323 is connected to the third end of the reference adjustment circuit 2322, used to receive the reference voltage signal; the second input end of the comparator 2323 is connected to the second end of the switchable resistance circuit 2321 and the thermistor circuit 21, used to receive the temperature signal; and the output end of the comparator 2323 is used to output a temperature protection signal according to the temperature signal and the reference voltage signal, so that the temperature protection threshold of the temperature protection circuit 232 is flexibly adjusted by the switchable resistance circuit 2321, and the temperature hysteresis protection is performed by the reference adjustment circuit 2322, thereby improving the reliability of the temperature protection circuit 232.

[0050] In one embodiment, the switchable resistor circuit 2321 includes N first resistors 232a and N bypass circuits 232b, where N ≥ 2; the N first resistors 232a are connected in series between the power input terminal and the thermistor circuit 21; each first resistor is connected in parallel with a bypass circuit.

[0051] In this embodiment, by bypassing part of the first resistor in the switchable resistor circuit 2321 through the side circuit, the resistance value of the switchable resistor can be adjusted, thereby adjusting the voltage division ratio between the switchable resistor circuit 2321 and the thermistor circuit 21, and adjusting the temperature protection threshold of the temperature protection circuit 232. The circuit structure is simple and the cost is low.

[0052] Optionally, the bypass circuit includes a fuse or a switching transistor.

[0053] In one embodiment, the bypass circuit includes a fuse. Exemplarily, such as... Figure 1 As shown, the N first resistors 232a include resistors R1 to R6. Resistors R1 to R6 are connected in parallel with fuses F1 to F5, respectively. Different fuses can be blown according to different needs during the manufacturing process of the battery protection chip 23, changing the voltage division ratio between the switchable resistor circuit 2321 and the thermistor circuit 21, thereby changing the temperature protection threshold of the temperature protection circuit 232.

[0054] In one embodiment, the reference adjustment circuit 2322 includes a first resistor circuit 232c, a second resistor circuit 232d, a third resistor circuit 232e, a first switch Q2, and a second switch Q3. The first resistor circuit 232c, the second resistor circuit 232d, and the third resistor circuit 232e are connected in series between the power input terminal and ground. The first terminal of the first switch Q2 is connected to the first resistor circuit 232c and the second resistor circuit 232d, the second terminal of the first switch Q2 is connected to the first input terminal of the comparator 2323, and the third terminal of the first switch Q2 is used to receive the first reference adjustment signal Hys_0TA. The first terminal of the second switch Q3 is connected to the second resistor circuit 232d and the third resistor circuit 232e, the second terminal of the second switch Q3 is connected to the first input terminal of the comparator 2323, and the third terminal of the second switch Q3 is used to receive the second reference adjustment signal Hys_0TB.

[0055] As an example, the first resistor circuit 232c, the second resistor circuit 232d, or the third resistor circuit 232e may include one resistor or multiple resistors. When multiple resistors are included, they may be connected in series and / or in parallel. Exemplarily, the first resistor circuit 232c includes resistor R7, the second resistor circuit 232d includes resistor R8, and the third resistor circuit 232e includes resistor R9.

[0056] As an example, the first switch tube Q2 and the second switch tube Q3 are MOS tubes. As an example, the first switch tube Q2 and the second switch tube Q3 are NMOS tubes. The drain of the first switch tube Q2 is connected to a connection node between the first resistance circuit 232c and the second resistance circuit 232d, the source of the first switch tube Q2 is connected to the first input end of the comparator 2323, and the gate of the first switch tube Q2 is used to receive the first reference adjustment signal Hys_0TA. The drain of the second switch tube Q3 is connected to a connection node between the second resistance circuit 232d and the third resistance circuit 232e, the source of the second switch tube Q3 is connected to the first input end of the comparator 2323, and the gate of the second switch tube Q3 is used to receive the second reference adjustment signal Hys_0TB.

[0057] As an example, the first reference adjustment signal Hys_0TA and the second reference adjustment signal Hys_0TB can be signals output by the logic control circuit 231 in the battery protection chip 23.

[0058] As an example, the thermistor circuit 21 includes a thermistor RNTC. If a temperature protection threshold of 80℃ is required, the resistors R7, R8 and R9 are configured to satisfy R9 / (R7+R8+R9)=1 / 11. Through the preset thermistor and temperature mapping table, it is found that the RNTC resistance value at this time should be 1.66kΩ, and the fuses F1 to F5 are blown, so that R1+R2+R3+R4+R5+R6=16.6kΩ. At this time, the first switch tube Q2 is controlled to be turned off, the second switch tube Q3 is turned on, the first input end voltage V1 of the comparator 2323 is R9 / (R7+R8+R9), and the second input end voltage V2 of the comparator 2323 is RNTC / ((R1+R2+R3+R4+R5+R6)+RNTC). At this time, V1=V2, and when the temperature continues to rise, the thermistor RNTC resistance value decreases, V2 is greater than V1, the comparator 2323 flips, and the temperature protection is triggered. The logic control circuit 231 controls the charging and discharging switch circuit 22 to be turned off. After the logic control circuit 231 controls the charging and discharging switch circuit 22 to be turned off, the first switch tube Q2 is turned on, and the second switch tube Q3 is turned off. At this time, the temperature protection recovery threshold is preset to (80℃-10℃)=70℃, and when the battery 1 environment temperature recovers to 70℃, the comparator 2323 is reversed again, the temperature protection is released, and the logic control circuit 231 controls the charging and discharging switch circuit 22 to be turned on again. It should be noted that when other temperature protection thresholds are required, only the fusing relationship of F1 to F5 needs to be modified, so as to configure different temperature protection thresholds.

[0059] In an embodiment, the temperature protection circuit 232 further comprises a third switch tube Q1, a first end of the third switch tube Q1 is configured to be connected to the power input end, a second end of the third switch tube Q1 is connected to the first end of the switchable resistance circuit 2321 and the first end of the reference adjustment circuit 2322, and a third end of the third switch tube Q1 is configured to receive the first clock signal t_0T.

[0060] As an example, the third switch tube Q1 is a MOS tube. As an example, the third switch tube Q1 is an NMOS tube. The drain of the third switch tube Q1 is connected to the power input end, the source of the third switch tube Q1 is connected to the first end of the switchable resistance circuit 2321 and the first end of the reference adjustment circuit 2322, and the gate of the third switch tube Q1 is configured to receive the first clock signal t_0T. Thus, by configuring the first clock signal t_0T, the conduction frequency of the third switch tube Q1 is controlled, the power efficiency is improved, and the energy loss is reduced.

[0061] In an embodiment, the temperature protection circuit 232 further comprises a D flip-flop 2324, a first input end of the D flip-flop 2324 is connected to the output end of the comparator 2323, a second input end of the D flip-flop 2324 is configured to receive a second clock signal CLK_MOT, and an output end of the D flip-flop 2324 is configured to output a temperature protection signal.

[0062] In the embodiment, the first input end VOUT of the D flip-flop 2324 is connected to the output end of the comparator 2323, the second input end of the D flip-flop 2324 is configured to receive the second clock signal CLK_MOT, and the output end DET_MOT of the D flip-flop 2324 is configured to output the temperature protection signal. By using the second clock signal CLK_MOT to control the D flip-flop 2324 to transmit the temperature protection signal output by the comparator 2323 to the logic control circuit 231, periodic detection can be realized, and power consumption is reduced. As an example, the high level period of the second clock signal CLK_MOT is 8 ms.

[0063] The embodiment provides a battery protection chip 23, comprising a logic control circuit 231 and the temperature protection circuit 232 described above; the temperature protection circuit 232 is connected to the logic control circuit 231 and is configured to output a temperature protection signal to the logic control circuit 231; and the logic control circuit 231 is configured to be connected to the charge-discharge switch circuit 22 and is configured to control the charge-discharge switch circuit 22 to work according to the temperature protection signal.

[0064] In the embodiment, the logic control circuit 231 and the temperature protection circuit 232 described above are integrated in a chip, and only the thermistor circuit 21 is arranged outside the chip, so that the integration degree is improved and the application cost is reduced.

[0065] The embodiment provides a charge-discharge control circuit 2, which comprises a thermistor circuit 21, a charge-discharge switch circuit 22 and the battery protection chip 23; the thermistor circuit 21 is used for detecting an ambient temperature; the charge-discharge switch circuit 22 is used for connecting the battery 1 and a charge-discharge connection end; a temperature protection circuit 232 is connected with the thermistor circuit 21, and a logic control circuit 231 is connected with the charge-discharge switch circuit 22. Exemplarily, the thermistor circuit 21 is arranged in contact with the battery 1, so as to accurately collect the ambient temperature around the battery 1. In the embodiment, the thermistor circuit 21 is used for detecting the ambient temperature; the charge-discharge switch circuit 22 is used for connecting the battery 1 and the charge-discharge connection end; the temperature protection circuit 232 is connected with the thermistor circuit 21, and the logic control circuit 231 is connected with the charge-discharge switch circuit 22; the temperature protection threshold of the temperature protection circuit 232 is flexibly adjusted through a switchable resistance circuit 2321, and temperature hysteresis protection is performed through a reference adjustment circuit 2322, so that the reliability of the temperature protection circuit 232 is improved, and periodic detection is realized, and power consumption is reduced.

[0066] The embodiment provides a charge-discharge control system, which comprises the battery 1 and the charge-discharge control circuit 2.

[0067] The embodiment provides a battery module, which comprises the charge-discharge control system.

[0068] The above embodiment is only used for describing the technical scheme of the utility model, and is not used for limiting the utility model; although the utility model is described in detail with reference to the foregoing embodiment, it should be understood by those skilled in the art that the technical scheme recorded in the foregoing embodiment can be modified, or some technical features can be replaced equivalently; and the modification or replacement does not make the essence of the corresponding technical scheme deviate from the spirit and range of the technical scheme of the embodiment of the utility model, and should be included in the protection range of the utility model.

Claims

1. A temperature protection circuit, characterized by, The temperature protection circuit comprises a switchable resistance circuit, a reference adjustment circuit and a comparator: a first end of the switchable resistance circuit is connected with a power input end, and a second end of the switchable resistance circuit is used for connecting a thermistor circuit; a first end of the reference adjustment circuit is used for connecting the power input end, a second end of the reference adjustment circuit is grounded, a third end of the reference adjustment circuit is used for outputting a reference voltage signal, and a control end of the reference adjustment circuit is used for receiving a reference adjustment signal; a first input end of the comparator is connected with the third end of the reference adjustment circuit, and is used for receiving the reference voltage signal; a second input end of the comparator is connected with the second end of the switchable resistance circuit and the thermistor circuit, and is used for receiving a temperature signal; and an output end of the comparator is used for outputting a temperature protection signal according to the temperature signal and the reference voltage signal.

2. The temperature protection circuit of claim 1, wherein, The switchable resistance circuit comprises N first resistors and N bypass circuits, and N≥2; N first resistors are arranged in series between the power input end and the thermistor circuit; Each first resistor is connected in parallel with a bypass circuit.

3. The temperature protection circuit of claim 2, wherein, The bypass circuit comprises a fuse.

4. The temperature protection circuit of claim 2, wherein, The reference adjustment circuit comprises a first resistance circuit, a second resistance circuit, a third resistance circuit, a first switch tube and a second switch tube; The first resistance circuit, the second resistance circuit and the third resistance circuit are arranged in series between the power input end and the ground; a first end of the first switch tube is connected with the first resistance circuit and the second resistance circuit, a second end of the first switch tube is connected with the first input end of the comparator, and a third end of the first switch tube is used for receiving a first reference adjustment signal; a first end of the second switch tube is connected with the second resistance circuit and the third resistance circuit, a second end of the second switch tube is connected with the first input end of the comparator, and a third end of the second switch tube is used for receiving a second reference adjustment signal.

5. The temperature protection circuit of claim 1, wherein, The temperature protection circuit further comprises a third switch tube; a first end of the third switch tube is used for connecting the power input end, a second end of the third switch tube is connected with the first end of the switchable resistance circuit and the first end of the reference adjustment circuit, and a third end of the third switch tube is used for receiving a first clock signal.

6. The temperature protection circuit of claim 1, wherein, The temperature protection circuit further comprises a D flip-flop; a first input end of the D flip-flop is connected with the output end of the comparator, a second input end of the D flip-flop is used for receiving a second clock signal, and an output end of the D flip-flop is used for outputting the temperature protection signal.

7. A battery protection chip, characterized in that, The temperature protection circuit comprises a logic control circuit and the temperature protection circuit according to any one of claims 1 to 6; The temperature protection circuit is connected with the logic control circuit, and is used for outputting a temperature protection signal to the logic control circuit; The logic control circuit is used for connecting a charge-discharge switching circuit, and is used for controlling the charge-discharge switching circuit to work according to the temperature protection signal.

8. A charge-discharge control circuit characterized by comprising: The temperature protection circuit comprises a thermistor circuit, a charge-discharge switching circuit and the battery protection chip according to claim 7; The thermistor circuit is used for detecting an ambient temperature; The charge-discharge switch circuit is used for connecting the battery and the charge-discharge connection end. The temperature protection circuit is connected with the thermistor circuit, and the logic control circuit is connected with the charge-discharge switch circuit.

9. A charge-discharge control system characterized by comprising: The battery and the charge-discharge control circuit of claim 8 are included. The battery is connected with the charge-discharge control circuit.

10. A battery module, characterized by The charge-discharge control system of claim 9 is included.

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