Charging and discharging control circuit, chip, system and battery module

Abstract

The utility model discloses a charge and discharge control circuit, a chip, a system and a battery module. The charge and discharge control circuit comprises a logic control unit, a first comparator, a charger detection unit and a driving unit. The in-phase input end of the first comparator is connected with a charging voltage sampling point, the reverse input end is grounded, and the output end outputs a voltage comparison signal; the charger detection unit feeds back the sampling voltage of the charging voltage sampling point to the driving unit; the logic control unit outputs a driving control signal to the driving unit according to the voltage comparison signal output by the first comparator; and the driving unit is used for outputting a preset pulse signal to the sampling voltage control circuit, and controlling the charging switch tube to be switched on and controlling the discharging switch tube to be switched off according to the driving control signal and the sampling voltage of the charging voltage sampling point when the charging interface is connected with a charger. According to the technical scheme, under the condition that the cruising ability of the battery is not affected, the battery is charged without discharging, the circuit structure is simple, and the cost is low.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a charging and discharging control circuit, chip, system and battery module. Background Technology

[0002] In some electrically powered mobile products, discharging must be prohibited during the charging phase to ensure personnel safety and prevent accidental activation during charging, which could lead to safety accidents. Therefore, such products generally require a battery charging-without-discharging design to ensure safety during the charging process.

[0003] In existing technologies, a Schottky diode is typically placed in the product's charging port. When a charger is connected, the presence of the Schottky diode causes a negative voltage to appear in the charging port. The presence of the charger is detected by sensing this negative voltage, thus preventing discharge when the charger is detected. However, this solution has a drawback: the presence of a Schottky diode in the charging port can prevent the battery from reaching a full charge state, affecting the product's battery life. Utility Model Content

[0004] This utility model provides a charge / discharge control circuit, chip, system, and battery module to solve the problem that existing charge / discharge control circuits affect battery life when charging without discharging.

[0005] A charging and discharging control circuit includes a logic control unit, a first comparator, a charger detection unit, and a drive unit;

[0006] The non-inverting input of the first comparator is used to connect to the charging voltage sampling point, the inverting input of the first comparator is grounded, and the output of the first comparator is used to output a voltage comparison signal.

[0007] The charger detection unit is connected to the charging voltage sampling point and the driving unit, and is used to feed back the sampling voltage of the charging voltage sampling point to the driving unit;

[0008] The logic control unit is connected to the first comparator and the driving unit, and is used to output a driving control signal to the driving unit according to the voltage comparison signal output by the first comparator.

[0009] The driving unit is used to connect the charging switch, the discharging switch and the sampling voltage control circuit, and to output a preset pulse signal to the sampling voltage control circuit. When the charger is connected to the charging interface, the driving control signal and the sampling voltage of the charging voltage sampling point are used to control the charging switch to turn on and the discharging switch to turn off.

[0010] A charge / discharge control chip includes the charge / discharge control circuit described above.

[0011] A charging and discharging control system includes the aforementioned charging and discharging control chip, charging switch transistor, discharging switch transistor, and sampling voltage control circuit.

[0012] The charging switch is connected in series between the battery and the charging interface, and a charging voltage sampling point is provided between the charging switch and the charging interface;

[0013] The discharge switch is connected in series between the battery and the discharge interface;

[0014] The sampling voltage control circuit is connected to the battery, the charge / discharge control chip, and the charging switch transistor, and is used to control the sampling voltage of the charging voltage sampling point according to the preset pulse signal output by the charge / discharge control chip.

[0015] The charge / discharge control chip is connected to the charging switch, the discharging switch, the sampling voltage control circuit, and the charging voltage sampling point. When the charger is connected to the charging interface, the chip controls the charging switch to turn on and the discharging switch to turn off based on the sampling voltage of the charging voltage sampling point.

[0016] Furthermore, the charge-discharge control system includes a first resistor circuit;

[0017] The first end of the first resistor circuit is connected to the charge / discharge control chip, and the second end of the first resistor circuit is connected to the charging voltage sampling point.

[0018] Furthermore, the sampling voltage control circuit includes a first switching transistor;

[0019] The first terminal of the first switching transistor is connected to the battery, the second terminal of the first switching transistor is connected to the charging switching transistor, and the third terminal of the first switching transistor is connected to the charging and discharging control chip.

[0020] Furthermore, the first switch is a field-effect transistor;

[0021] The source of the first switching transistor is connected to the battery, the drain of the first switching transistor is connected to the charging switching transistor, and the gate of the first switching transistor is connected to the charging and discharging control chip.

[0022] Furthermore, the charging interface includes a positive charging interface and a negative charging interface;

[0023] The positive charging interface and the negative charging interface are connected by a second resistor circuit;

[0024] The charging voltage sampling point is provided between the charging switch and the charging negative terminal interface.

[0025] Furthermore, the charging and discharging control system also includes a switch driving circuit;

[0026] The first terminal of the switch driving circuit is connected to the charge / discharge control chip, and the second terminal of the switch driving circuit is connected to the charging switch transistor, which is used to drive the charging switch transistor to work.

[0027] Furthermore, the switch driving circuit includes a first transistor, a first voltage divider circuit, and a third resistor circuit;

[0028] The first terminal of the first transistor is connected to the charge / discharge control chip, and the second terminal of the first transistor is connected to the charging switch.

[0029] The first terminal of the first voltage divider circuit is connected to the charge / discharge control chip, the second terminal of the first voltage divider circuit is grounded, and the third terminal of the first voltage divider circuit is connected to the third terminal of the first transistor.

[0030] The first end of the third resistor circuit is connected to the connection node between the second end of the first transistor and the charging switch, and the second end of the third resistor circuit is connected to the charging interface.

[0031] A battery module includes a battery and the aforementioned charging and discharging control system.

[0032] The aforementioned charge / discharge control circuit, chip, system, and battery module include a charge / discharge control circuit comprising a logic control unit, a first comparator, a charger detection unit, and a drive unit. The non-inverting input of the first comparator is connected to the charging voltage sampling point, the inverting input is grounded, and the output of the first comparator is used to output a voltage comparison signal. The charger detection unit is connected to the charging voltage sampling point and the drive unit, and is used to feed back the sampled voltage of the charging voltage sampling point to the drive unit. The logic control unit is connected to the first comparator and the drive unit, and is used to output a drive control signal to the drive unit based on the voltage comparison signal output by the first comparator. The drive unit is used to connect the charging switch transistor, the discharging switch transistor, and the sampling voltage. The control circuit outputs a preset pulse signal to the sampling voltage control circuit. When the charger is connected to the charging interface, it controls the charging switch to turn on and the discharging switch to turn off based on the drive control signal and the sampling voltage of the charging voltage sampling point. By outputting the preset pulse signal to the sampling voltage control circuit, the sampling voltage of the charging voltage sampling point is controlled by the sampling voltage control circuit when the charger is connected or removed. This allows the drive unit to accurately control the charging switch to turn on and the discharging switch to turn off when the charger is connected, based on the newly acquired sampling voltage. Thus, the battery can be charged without discharging without affecting the battery's range. The circuit structure is simple and the cost is low. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a circuit diagram of a charge / discharge control chip in one embodiment of the present invention;

[0035] Figure 2 This is a circuit diagram of a charging and discharging control system in one embodiment of the present invention;

[0036] Figure 3 This is a timing diagram of charger connection detection in one embodiment of this utility model;

[0037] Figure 4 This is a timing diagram of charger removal detection in one embodiment of the present invention.

[0038] In the diagram: 1. Charge / discharge control chip; 11. Logic control unit; 12. First comparator; 13. Charger detection unit; 14. Drive unit; 2. Charging switch transistor; 3. Discharging switch transistor; 4. Sampling voltage control circuit; 5. First resistor circuit; 6. Switch drive circuit; 61. First voltage divider circuit; 62. Third resistor circuit; 7. Second resistor circuit. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0040] It should be understood that this invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this invention to those skilled in the art. In the drawings, for clarity, the dimensions of layers and regions, as well as their relative dimensions, may be exaggerated. The same reference numerals denote the same elements throughout.

[0041] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this utility model, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0042] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0043] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. When used herein, the singular forms “a,” “an,” and “ / the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “comprising,” when used in this specification, identify the presence of features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0044] To fully understand this utility model, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by this utility model. Preferred embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0045] This embodiment provides a charge / discharge control circuit, applied in a charge / discharge control chip 1. This charge / discharge control chip 1 can be applied in a charge / discharge control system. For example, as shown... Figure 2 As shown, this charge / discharge control system is applied to a battery module to prevent the battery module from discharging while it is charging, thereby improving the safety of certain electronic products when the battery module is used in them. These specific electronic products include mobile electronic products.

[0046] As an example, the charge / discharge control system includes the aforementioned charge / discharge control chip 1, charging switch 2, discharging switch 3, and sampling voltage control circuit 4; the charging switch 2 is connected in series between the battery and the charging interface, and a charging voltage sampling point is provided between the charging switch 2 and the charging interface; the discharging switch 3 is connected in series between the battery and the discharging interface; the sampling voltage control circuit 4 is connected to the battery, the charge / discharge control chip 1, and the charging switch 2, and is used to control the sampling voltage of the charging voltage sampling point according to the preset pulse signal output by the charge / discharge control chip 1; the charge / discharge control chip 1 is connected to the charging switch 2, the discharging switch 3, the sampling voltage control circuit 4, and the charging voltage sampling point, and is used to control the charging switch 2 to conduct and the discharging switch 3 to disconnect according to the sampling voltage of the charging voltage sampling point when the charger is connected to the charging interface.

[0047] The charging interface is used to connect a charger. The discharging interface is used to connect a load. The load can be understood as various functional modules or electronic devices in an electronic product that require power. The battery can include a single cell or multiple cells. The cell can be a lithium-ion cell. The preset pulse signal can be a square wave signal. For example, the square wave signal has a period of 64 milliseconds, and the delay time of the low-level signal within each period is 1 millisecond.

[0048] As an example, the charge / discharge control system includes a first resistor circuit 5; the first terminal of the first resistor circuit 5 is connected to the charge / discharge control chip 1, and the second terminal of the first resistor circuit 5 is connected to a charging voltage sampling point. The charging interface includes a positive charging interface P+ and a negative charging interface CH-; the positive charging interface P+ and the negative charging interface CH- are connected by a second resistor circuit 7; a charging voltage sampling point is provided between the charging switch 2 and the negative charging interface CH-. As an example, the second resistor circuit 7 includes a resistor R. CHP .

[0049] As an example, when a charger is connected to the charging port, the sampling voltage at the charging voltage sampling point is pulled low. When the low-level signal of the preset pulse signal arrives, the sampling voltage control circuit 4 controls the sampling voltage at the charging voltage sampling point to be negative. When the charging and discharging control chip 1 detects that the sampling voltage at the charging voltage sampling point is negative, it determines that a charger is present at the charging port. When the preset pulse signal returns from a low-level signal to a high-level signal, the sampling voltage at the charging voltage sampling point becomes a near-zero negative voltage. This near-zero negative voltage is understood to be determined by the internal resistance of the charging switch 2 and the sampling voltage control circuit 4. When the next low-level signal of the preset pulse signal arrives again, the above-mentioned repeated action is performed. This process continues until the presence of a charger is detected N times consecutively. At this point, the charging and discharging control chip 1 can determine that a charger is present at the charging port to prevent misjudgment. Simultaneously, it controls the charging switch 2 to turn on and the discharging switch 3 to turn off, thus achieving charging without discharging and ensuring safety during the charging process. Here, N≧2.

[0050] As another example, when the charger is removed from the charging port and a low-level signal of the preset pulse signal arrives, the sampling voltage control circuit 4 controls the sampling voltage of the charging voltage sampling point to be a positive voltage. When the charging and discharging control chip 1 detects that the sampling voltage of the charging voltage sampling point is positive, it determines that there is no charger at the charging port. When the preset pulse signal returns from a low-level signal to a high-level signal, the sampling voltage of the charging voltage sampling point becomes a positive voltage close to zero. When the next low-level signal of the preset pulse signal arrives again, the above-mentioned repeated action is performed. Until the absence of the charger is detected N times consecutively, the charging and discharging control chip 1 can determine that there is no charger at the charging port and control the discharge switch 3 to conduct, thereby allowing the discharge switch 3 to conduct when there is no charger. The aforementioned near-zero positive voltage is determined by the discharge current generated by the second resistor circuit 7 and the internal resistance of the charging switch 2 and the sampling voltage control circuit 4.

[0051] In this embodiment, the charging switch 2 is connected in series between the battery and the charging interface, and a charging voltage sampling point is provided between the charging switch 2 and the charging interface; the discharging switch 3 is connected in series between the battery and the discharging interface; the sampling voltage control circuit 4 is connected to the battery, the charge / discharge control chip 1 and the charging switch 2, and is used to control the sampling voltage of the charging voltage sampling point according to the preset pulse signal output by the charge / discharge control chip 1; the charge / discharge control chip 1 is connected to the charging switch 2, the discharging switch 3, the sampling voltage control circuit 4 and the charging voltage sampling point, and is used to control the charging switch 2 to conduct and the discharging switch 3 to disconnect according to the sampling voltage of the charging voltage sampling point when the charger is connected to the charging interface. Thus, when the charger is connected to the charging interface, the sampling voltage of the charging voltage sampling point is controlled by the sampling voltage control circuit 4, so that the charge / discharge control chip 1 can determine the presence of the charger by the sampling voltage, control the charging switch 2 to conduct and control the discharging switch 3 to disconnect, so as to achieve battery charging without discharging without affecting the battery's range, and the circuit structure is simple and the cost is low.

[0052] This embodiment provides a charge / discharge control circuit, such as... Figure 1 As shown, the system includes a logic control unit 11, a first comparator 12, a charger detection unit 13, and a drive unit 14. The non-inverting input of the first comparator 12 is connected to the charging voltage sampling point, the inverting input of the first comparator 12 is grounded, and the output of the first comparator 12 is used to output a voltage comparison signal. The charger detection unit 13 is connected to the charging voltage sampling point and the drive unit 14, and is used to feed back the sampling voltage of the charging voltage sampling point to the drive unit 14. The logic control unit 11 is connected to the first comparator 12 and the drive unit 14, and is used to output a drive control signal to the drive unit 14 according to the voltage comparison signal output by the first comparator 12. The drive unit 14 is used to connect the charging switch 2, the discharging switch 3, and the sampling voltage control circuit 4, and is used to output a preset pulse signal to the sampling voltage control circuit 4. When the charger is connected to the charging interface, the drive control signal and the sampling voltage of the charging voltage sampling point are used to control the charging switch 2 to turn on and the discharging switch 3 to turn off.

[0053] As an example, the non-inverting input of the first comparator 12 receives the sampled voltage of the charging voltage sampling point. When the sampled voltage is positive, the first comparator 12 outputs a voltage comparison signal at a high level. When the sampled voltage is negative, the first comparator 12 outputs a voltage comparison signal at a low level.

[0054] As an example, the charger detection unit 13 is connected to the charging voltage sampling point and the drive unit 14, and is used to feed back the sampling voltage of the charging voltage sampling point to the drive unit 14.

[0055] As an example, the logic control unit 11 is connected to the first comparator 12 and the drive unit 14, and is used to output a drive control signal to the drive unit 14 according to the voltage comparison signal output by the first comparator 12. Exemplarily, the drive control signal includes a sampling clock signal and a voltage comparison threshold corresponding to the voltage comparison signal; for example, when the voltage comparison signal is a high-level signal, it corresponds to the first voltage comparison threshold, and when the voltage comparison signal is a low-level signal, it corresponds to the second voltage comparison threshold.

[0056] As an example, when a charger is connected to the charging interface, the voltage comparison signal is a high-level signal. The driving unit 14 compares the sampled voltage of the charging voltage sampling point with a first voltage comparison threshold. It determines whether the sampled voltage is less than or equal to the first voltage comparison threshold when the preset pulse signal is low. That is, it determines that the sampled voltage of the charging voltage sampling point becomes a negative voltage close to zero. This first voltage comparison threshold is determined by the internal resistance of the charging switch 2 and the sampling voltage control circuit 4. When the driving unit 14 determines that the sampled voltage of the charging voltage sampling point becomes a negative voltage close to zero, and according to the sampling clock signal, determines that the sampled voltage of the charging voltage sampling point has been detected to be a negative voltage close to zero N times consecutively, that is, the presence of a charger is detected, the charge / discharge control chip 1 can determine that a charger is present at the charging interface to prevent misjudgment. Simultaneously, it controls the charging switch 2 to turn on and the discharging switch 3 to turn off, thus achieving charging without discharging and ensuring safety during the charging process. See also... Figure 3 As shown in the charger connection detection timing diagram, when the preset pulse signal is detected for the first time and the sampling voltage is close to zero volts, the charger detection signal is a high-level signal. When the preset pulse signal is detected for the third time and the sampling voltage is close to zero volts, the charger judgment signal is a high-level signal. The charge and discharge control chip 1 judges that the charger exists and outputs a low-level control signal DO control signal to control the discharge switch 3 to turn off.

[0057] As another example, when the charger is removed from the charging port, the voltage comparison signal is a low-level signal. The driving unit 14 compares the sampled voltage of the charging voltage sampling point with the second voltage comparison threshold. It determines whether the sampled voltage is less than or equal to the second voltage comparison threshold when the preset pulse signal is low. That is, it determines that the sampled voltage of the charging voltage sampling point becomes a positive voltage close to zero. This second voltage comparison threshold is determined by the discharge current generated by the second resistor circuit 7, and the internal resistance of the charging switch 2 and the sampling voltage control circuit 4. When the driving unit 14 determines that the sampled voltage of the charging voltage sampling point becomes a positive voltage close to zero, and according to the sampling clock signal, determines that the sampled voltage of the charging voltage sampling point has been detected to be a positive voltage close to zero N times consecutively, that is, the charger is detected to be absent, the charge / discharge control chip 1 can determine that the charging port does not have a charger, to prevent misjudgment by the charge / discharge control chip 1. Simultaneously, it controls the discharge switch 3 to conduct to allow discharge and ensure safety during the charging process. See also... Figure 4 As shown in the charger removal detection timing diagram, when the preset pulse signal is detected for the first time and the sampling voltage is close to zero volts, the charger detection signal is a low-level signal. When the preset pulse signal is detected for the third time and the sampling voltage is close to zero volts, the charger judgment signal is a low-level signal. The charge / discharge control chip 1 determines that the charger does not exist and outputs a high-level control signal DO control signal to control the discharge switch 3 to turn on.

[0058] In this embodiment, the charge / discharge control circuit includes a logic control unit 11, a first comparator 12, a charger detection unit 13, and a drive unit 14. The non-inverting input of the first comparator 12 is connected to the charging voltage sampling point, the inverting input of the first comparator 12 is grounded, and the output of the first comparator 12 is used to output a voltage comparison signal. The charger detection unit 13 is connected to the charging voltage sampling point and the drive unit 14, and is used to feed back the sampled voltage of the charging voltage sampling point to the drive unit 14. The logic control unit 11 is connected to the first comparator 12 and the drive unit 14, and is used to output a drive control signal to the drive unit 14 according to the voltage comparison signal output by the first comparator 12. The drive unit 14 is used to connect the charging switch 2 and the discharging switch 3. The sampling voltage control circuit 4 outputs a preset pulse signal to the sampling voltage control circuit 4. When the charger is connected to the charging interface, the driving control signal and the sampling voltage of the charging voltage sampling point are used to control the charging switch 2 to turn on and the discharging switch 3 to turn off. Thus, by outputting a preset pulse signal to the sampling voltage control circuit 4, the sampling voltage of the charging voltage sampling point is controlled by the sampling voltage control circuit 4 when the charger is connected or removed. This allows the driving unit 14 to accurately control the charging switch 2 to turn on and the discharging switch 3 to turn off when the charger is connected, based on the re-collected sampling voltage. This achieves charging without discharging the battery without affecting the battery's range, and the circuit structure is simple and the cost is low.

[0059] This embodiment provides a charge / discharge control chip 1, including the aforementioned charge / discharge control circuit. In this embodiment, by integrating the charge / discharge control circuit into the charge / discharge control chip 1, the circuit integration and flexibility of use are improved.

[0060] This embodiment provides a charging and discharging control system, including the aforementioned charging and discharging control chip 1, charging switch 2, discharging switch 3, and sampling voltage control circuit 4; the charging switch 2 is connected in series between the battery and the charging interface, and a charging voltage sampling point is provided between the charging switch 2 and the charging interface; the discharging switch 3 is connected in series between the battery and the discharging interface; the sampling voltage control circuit 4 is connected to the battery, the charging and discharging control chip 1 (CHCT terminal), and the charging switch 2, and is used to control the sampling voltage of the charging voltage sampling point according to the preset pulse signal output by the charging and discharging control chip 1; the charging and discharging control chip 1 and the charging switch 2... The discharge switch 3, sampling voltage control circuit 4, and charging voltage sampling point are connected. When a charger is connected to the charging interface, the sampling voltage at the charging voltage sampling point controls the charging switch 2 to turn on and the discharge switch 3 to turn off. Thus, when a charger is connected to the charging interface, the sampling voltage at the charging voltage sampling point is controlled by the sampling voltage control circuit 4, allowing the charge / discharge control chip 1 to determine the presence of the charger, control the charging switch 2 to turn on, and control the discharge switch 3 to turn off. This achieves battery charging without discharging without affecting battery life, and the circuit structure is simple and low-cost. It should be noted that the working principle of the charge / discharge control system provided in this embodiment is the same as that in the above embodiments, and will not be repeated here.

[0061] In one embodiment, the charge / discharge control system includes a first resistor circuit 5; a first terminal of the first resistor circuit 5 is connected to the charge / discharge control chip 1 (CHAR terminal), and a second terminal of the first resistor circuit 5 is connected to a charging voltage sampling point. Exemplarily, the first resistor circuit 5 may include one or more resistors, which are connected in series and / or in parallel. The resistance value of the first resistor circuit 5 can be set according to actual needs and is not limited herein. Exemplarily, such as... Figure 2 As shown, the first resistor circuit 5 includes resistor R. CHAR .

[0062] In one embodiment, the sampling voltage control circuit 4 includes a first switching transistor NM2; the first terminal of the first switching transistor NM2 is connected to the battery, the second terminal of the first switching transistor NM2 is connected to the charging switching transistor 2, and the third terminal of the first switching transistor NM2 is connected to the charge / discharge control chip 1 (CHCT terminal).

[0063] As an example, when the charger is connected, the charging voltage sampling point is pulled low. When the preset pulse signal low level signal arrives, the first switch NM2 is turned off, and the charging current flows through the body diode of the first switch NM2. Therefore, the sampling voltage of the charging voltage sampling point will be -0.7V. The first comparator 12 and the logic control unit 11 inside the charge and discharge control chip 1 detect that the charging voltage sampling point is negative and consider that the charger is present. According to the sampling clock signal, if the sampling voltage of the charging voltage sampling point is detected to be close to zero negative voltage for N consecutive times, that is, the charger is detected, the charge and discharge control chip 1 can determine that the charging interface has a charger to prevent the charge and discharge control chip 1 from misjudging.

[0064] In one embodiment, the first switch NM2 is a field-effect transistor; the source of the first switch NM2 is connected to the battery, the drain of the first switch NM2 is connected to the charging switch 2, and the gate of the first switch NM2 is connected to the charge / discharge control chip 1.

[0065] In this embodiment, when the charger is connected, the charging voltage sampling point is pulled low. When the preset pulse signal low level signal arrives, the first switch NM2 is turned off, and the charging current flows through the body diode of the first switch NM2. Therefore, the sampling voltage of the charging voltage sampling point will be the conduction voltage of the body diode of the first switch NM2. The first comparator 12 and the logic control unit 11 inside the charge and discharge control chip 1 detect that the charging voltage sampling point is negative and consider that the charger is present.

[0066] As an example, the charging switch 2 is a field-effect transistor. The drain of the charging switch 2 is connected to the drain of the first switch NM2, the source of the charging switch 2 is connected to the charging interface, and the gate of the charging switch 2 is connected to the charge / discharge control chip 1 (DO terminal).

[0067] As an example, the discharge switch 3 is a field-effect transistor, the source of the charging switch 2 is connected to the battery, the drain of the charging switch 2 is connected to the discharge interface, and the gate of the charging switch 2 is connected to the charge / discharge control chip 1 (CO terminal).

[0068] In one embodiment, the charging interface includes a positive charging interface P+ and a negative charging interface CH-; the positive charging interface P+ and the negative charging interface CH- are connected by a second resistor circuit 7; a charging voltage sampling point is provided between the charging switch 2 and the negative charging interface CH-.

[0069] In this embodiment, the second resistor circuit 7 may include one or more resistors, which are connected in series and / or in parallel. The resistance value of the second resistor circuit 7 can be set according to actual needs and is not limited here.

[0070] In one embodiment, the charge and discharge control system further includes a switch driving circuit 6; the first end of the switch driving circuit 6 is connected to the charge and discharge control chip 1, and the second end of the switch driving circuit 6 is connected to the charging switch 2, for driving the charging switch 2 to work.

[0071] In this embodiment, the first end of the switch driving circuit 6 is connected to the charge / discharge control chip 1, and the second end of the switch driving circuit 6 is connected to the charging switch 2 to drive the charging switch 2 to work, so as to ensure the stability of the charging switch 2 during operation.

[0072] In one embodiment, the switch driving circuit 6 includes a first transistor Q1, a first voltage divider circuit 61, and a third resistor circuit 62; the first terminal of the first transistor Q1 is connected to the charge / discharge control chip 1, and the second terminal of the first transistor Q1 is connected to the charging switch 2; the first terminal of the first voltage divider circuit 61 is connected to the charge / discharge control chip 1, the second terminal of the first voltage divider circuit 61 is grounded, and the third terminal of the first voltage divider circuit 61 is connected to the third terminal of the first transistor Q1; the first terminal of the third resistor circuit 62 is connected to the connection node between the second terminal of the first transistor Q1 and the charging switch 2, and the second terminal of the third resistor circuit 62 is connected to the charging interface.

[0073] As an example, the first transistor Q1 can be a bipolar transistor or a field-effect transistor. Exemplarily, the first transistor Q1 is a bipolar transistor, the source of the first transistor Q1 is connected to the charge / discharge control chip 1, the emitter of the first transistor Q1 is connected to the charging switch 2 through the diode D1, and the base of the first transistor Q1 is connected to the third terminal of the first voltage divider circuit 61.

[0074] As an example, the first voltage divider circuit 61 includes a resistor R connected in series. Q1 and resistance R Q2 resistance R Q1 and resistance R Q2 The connection node between them is connected to the base of the first transistor Q1. The third resistor circuit 62 includes one or more resistors connected in series and / or in parallel. The resistance value of the third resistor circuit 62 can be set according to actual needs and is not limited here. For example, the third resistor circuit 62 includes a resistor RCO.

[0075] It should be noted that the charge-discharge control system also includes peripheral circuitry (not shown in the figure) disposed around the charge-discharge control chip 1. Exemplarily, this peripheral circuitry includes a charge-discharge protection circuit for the battery and a chip driver circuit for driving the charge-discharge control chip 1 to operate normally.

[0076] This embodiment provides a battery module, including a battery and the aforementioned charging and discharging control system.

[0077] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A charging and discharging control circuit, characterized in that, It includes a logic control unit, a first comparator, a charger detection unit, and a drive unit; The non-inverting input of the first comparator is used to connect to the charging voltage sampling point, the inverting input of the first comparator is grounded, and the output of the first comparator is used to output a voltage comparison signal. The charger detection unit is connected to the charging voltage sampling point and the driving unit, and is used to feed back the sampling voltage of the charging voltage sampling point to the driving unit; The logic control unit is connected to the first comparator and the driving unit, and is used to output a driving control signal to the driving unit according to the voltage comparison signal output by the first comparator. The driving unit is used to connect the charging switch, the discharging switch and the sampling voltage control circuit, and to output a preset pulse signal to the sampling voltage control circuit. When the charger is connected to the charging interface, the driving control signal and the sampling voltage of the charging voltage sampling point are used to control the charging switch to turn on and the discharging switch to turn off.

2. A charge / discharge control chip, characterized in that, Includes the charge / discharge control circuit as described in claim 1.

3. A charging and discharging control system, characterized in that, Includes the charge / discharge control chip, charging switch, discharging switch, and sampling voltage control circuit as described in claim 2; The charging switch is connected in series between the battery and the charging interface, and a charging voltage sampling point is provided between the charging switch and the charging interface; The discharge switch is connected in series between the battery and the discharge interface; The sampling voltage control circuit is connected to the battery, the charge / discharge control chip, and the charging switch transistor, and is used to control the sampling voltage of the charging voltage sampling point according to the preset pulse signal output by the charge / discharge control chip. The charge / discharge control chip is connected to the charging switch, the discharging switch, the sampling voltage control circuit, and the charging voltage sampling point. When the charger is connected to the charging interface, the chip controls the charging switch to turn on and the discharging switch to turn off based on the sampling voltage of the charging voltage sampling point.

4. The charging and discharging control system as described in claim 3, characterized in that, The charging and discharging control system includes a first resistor circuit. The first end of the first resistor circuit is connected to the charge / discharge control chip, and the second end of the first resistor circuit is connected to the charging voltage sampling point.

5. The charging and discharging control system as described in claim 3, characterized in that, The sampling voltage control circuit includes a first switching transistor; The first terminal of the first switching transistor is connected to the battery, the second terminal of the first switching transistor is connected to the charging switching transistor, and the third terminal of the first switching transistor is connected to the charging and discharging control chip.

6. The charging and discharging control system as described in claim 5, characterized in that, The first switch is a field-effect transistor; The source of the first switching transistor is connected to the battery, the drain of the first switching transistor is connected to the charging switching transistor, and the gate of the first switching transistor is connected to the charging and discharging control chip.

7. The charging and discharging control system as described in claim 3, characterized in that, The charging interface includes a positive charging interface and a negative charging interface; The positive charging interface and the negative charging interface are connected by a second resistor circuit; The charging voltage sampling point is provided between the charging switch and the charging negative terminal interface.

8. The charging and discharging control system as described in claim 3, characterized in that, The charging and discharging control system also includes a switch driving circuit. The first terminal of the switch driving circuit is connected to the charge / discharge control chip, and the second terminal of the switch driving circuit is connected to the charging switch transistor, which is used to drive the charging switch transistor to work.

9. The charging and discharging control system as described in claim 8, characterized in that, The switch driving circuit includes a first transistor, a first voltage divider circuit, and a third resistor circuit. The first terminal of the first transistor is connected to the charge / discharge control chip, and the second terminal of the first transistor is connected to the charging switch. The first terminal of the first voltage divider circuit is connected to the charge / discharge control chip, the second terminal of the first voltage divider circuit is grounded, and the third terminal of the first voltage divider circuit is connected to the third terminal of the first transistor. The first end of the third resistor circuit is connected to the connection node between the second end of the first transistor and the charging switch, and the second end of the third resistor circuit is connected to the charging interface.

10. A battery module, characterized in that, Includes a battery and a charge / discharge control system as described in any one of claims 3 to 9.

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