Over-discharge protection control circuit and electronic equipment

Abstract

The utility model provides an over-discharge protection control circuit and electronic equipment, and belongs to the technical field of electronics. The circuit is characterized in that a first end of a first switch unit is used for connecting a positive electrode of a battery, a second end of the first switch unit is used for respectively connecting a positive electrode of external equipment and an enabling end of a voltameter, and a third end of the first switch unit is connected with a first end of a first control unit; the sampling end of the voltameter is connected with the positive electrode of the battery and a ground wire, and the control end of the voltameter is connected with the first end of the sampling control unit; the second end of the sampling control unit is connected with the anode of the battery. According to the invention, the external discharge loop of the battery can be closed in advance when the actual voltage of the battery is not reduced to the over-discharge protection voltage, and the voltameter unit can enter a low-power-consumption dormant state when the external discharge loop of the battery is closed. Therefore, the service life of the battery can be prolonged as much as possible, and the possibility of safety problems such as swelling and liquid leakage of the battery is reduced.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and more specifically, to an over-discharge protection control circuit and electronic device. Background Technology

[0002] With the rapid development of electronic technology, all kinds of electronic products have entered people's work and life. Many electronic products are powered by batteries, so it is necessary to set up a fuel gauge in electronic products to detect relevant parameters and set up a protection circuit to prevent the battery from being over-discharged.

[0003] In related technologies, when the fuel gauge detects that the battery voltage is lower than the over-discharge protection value, the corresponding processing unit controls the discharge circuit to close, thereby disconnecting the transmission path of the battery to external devices and reducing most of the battery's power consumption. At this time, the voltage is generally 2.5V or lower.

[0004] However, this method results in the battery being over-discharged when the discharge circuit is closed. Prolonged exposure to this state can shorten battery life or cause issues such as bulging and leakage. Furthermore, the fuel gauge still consumes power in this state, leading to a continuous decrease in the battery cell voltage, which also shortens battery life. Utility Model Content

[0005] The purpose of this application is to provide an over-discharge protection control circuit and electronic device, which can not only shut down the battery's external discharge circuit in advance before the actual battery voltage drops to the over-discharge protection voltage, but also enable the fuel gauge unit to enter a low-power sleep state when shutting down the battery's external discharge circuit. In this way, the battery's service life can be extended as much as possible and the possibility of safety problems such as battery bulging and leakage can be reduced.

[0006] The embodiments of this application are implemented as follows:

[0007] A first aspect of this application provides an over-discharge protection control circuit, the circuit comprising: a first switching unit, a fuel meter, a sampling control unit, and a first control unit;

[0008] The first terminal of the first switching unit is used to connect to the positive terminal of the battery, the second terminal of the first switching unit is used to connect to the positive terminal of the external device and the enable terminal of the fuel gauge unit respectively, and the third terminal of the first switching unit is connected to the first terminal of the first control unit; the first switching unit is used to turn on or off under the control of the first control unit.

[0009] The sampling terminals of the fuel gauge unit are respectively connected to the positive terminal and the ground wire of the battery, and the control terminal of the fuel gauge unit is connected to the first terminal of the sampling control unit; the fuel gauge unit is used to collect the output voltage of the battery, and to control the sampling control unit to turn on when the output voltage is less than a preset voltage; the preset voltage is greater than the over-discharge protection voltage of the battery;

[0010] The second terminal of the sampling control unit is used to connect to the positive terminal of the battery, and the third terminal of the sampling control unit is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit, respectively; the sampling control unit is used to transmit the output voltage of the battery to the first control unit when it is turned on, so as to pull up the voltage of the second terminal of the first control unit.

[0011] The third terminal of the first control unit is used to connect to the positive terminal of the battery; the first control unit is used to control the first switching unit to turn off when the voltage difference between the second and third terminals of the first control unit is less than a first preset threshold.

[0012] Optionally, the sampling control unit includes at least: a first switching transistor and a first resistor;

[0013] The first terminal of the first switching transistor is connected to the first end of the first resistor, the second terminal of the first switching transistor is connected to the control terminal of the fuel gauge unit, and the third terminal of the first switching transistor is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit.

[0014] The second end of the first resistor is used to connect to the positive terminal of the battery;

[0015] The first switch is turned on under the control of the fuel gauge unit and transmits the output voltage of the battery to the first control unit.

[0016] Optionally, the first control unit includes: a first control chip and a first capacitor;

[0017] The first sampling terminal of the first control chip is used to connect to the positive terminal of the battery, and the second sampling terminal of the first control chip is used to connect to the third terminal of the sampling control unit, the negative terminal of the battery and the negative terminal of the external device, respectively. The first control terminal of the first control chip is connected to the third terminal of the first switching unit.

[0018] The first capacitor is connected between the first sampling terminal and the second sampling terminal of the first control chip.

[0019] Optionally, the first switching unit includes: at least one second switching transistor;

[0020] The first terminal of each of the second switching transistors is used to connect to the positive terminal of the battery, the second terminal of each of the second switching transistors is used to connect to the positive terminal of the external device, the third terminal of the second switching transistor is connected to the first terminal of the first control unit, and at least one of the second switching transistors is connected to the enable terminal of the fuel gauge unit.

[0021] Optionally, the first switching unit further includes: at least one third switching transistor, the number of which is the same as the number of the second switching transistors;

[0022] The first terminal of the third switch is connected to the positive terminal of the battery, the second terminal of the third switch is connected to the first terminal of the second switch, and the third terminal of the third switch is connected to the fourth terminal of the first control unit.

[0023] Optionally, the circuit further includes: a second switching unit and a second control unit;

[0024] The first end of the second switching unit is used to connect to the positive terminal of the battery, the second end of the second switching unit is connected to the first end of the first switching unit, and the third end of the second switching unit is connected to the first end of the second control unit; the second switching unit is used to turn on or off under the control of the second control unit.

[0025] The second terminal of the second control unit is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit, respectively. The third terminal of the second control unit is used to connect to the positive terminal of the battery. The second control unit is used to control the second switching unit to turn off when the voltage difference between the second terminal and the third terminal of the second control unit is less than a second preset threshold.

[0026] Optionally, the second control unit includes: a second control chip and a second capacitor;

[0027] The first sampling terminal of the second control chip is used to connect to the positive terminal of the battery, the second sampling terminal of the second control chip is used to connect to the negative terminal of the battery and the negative terminal of the external device, and the first control terminal of the second control chip is connected to the third terminal of the second switching unit.

[0028] The second capacitor is connected between the first sampling terminal and the second sampling terminal of the second control chip.

[0029] Optionally, the second switching unit includes at least one fourth switching transistor;

[0030] The first terminal of the fourth switch is connected to the positive terminal of the battery, the second terminal of the fourth switch is connected to the first terminal of the first switch unit, and the third terminal of the fourth switch is connected to the first terminal of the second control unit.

[0031] Optionally, the second switching unit further includes: at least one fifth switching transistor, the number of which is the same as the number of the fourth switching transistor;

[0032] The first terminal of the fifth switch is connected to the positive terminal of the battery, the second terminal of the fifth switch is connected to the first terminal of the fourth switch, and the third terminal of the fifth switch is connected to the fourth terminal of the second control unit.

[0033] A second aspect of this application provides an electronic device, which includes at least any of the over-discharge protection control circuits described in the first aspect above.

[0034] The beneficial effects of the embodiments of this application include:

[0035] This application provides an over-discharge protection control circuit, which includes a first switching unit, a fuel gauge unit, a sampling control unit, and a first control unit. Specifically, the first terminal of the first switching unit is connected to the positive terminal of the battery, the second terminal of the first switching unit is connected to the positive terminal of an external device and the enable terminal of the fuel gauge unit, and the third terminal of the first switching unit is connected to the first terminal of the first control unit. The sampling terminal of the fuel gauge unit is connected to the positive terminal of the battery and ground, and the control terminal of the fuel gauge unit is connected to the first terminal of the sampling control unit. The second terminal of the sampling control unit is connected to the positive terminal of the battery, and the third terminal of the sampling control unit is connected to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit. The third terminal of the first control unit is connected to the positive terminal of the battery.

[0036] Specifically, when the fuel gauge unit determines that the battery's output voltage is lower than the preset voltage, the fuel gauge unit controls the sampling control unit to turn on. The sampling control unit transmits the battery's output voltage to the second terminal of the first control unit, thereby raising the voltage at the second terminal of the first control unit. At this time, the voltage difference sampled between the second and third terminals of the first control unit will be less than the actual battery voltage. This allows the first switching unit to be turned off before the actual battery voltage drops to the over-discharge protection voltage (the battery has not yet triggered over-discharge protection), thus cutting off the battery's external discharge circuit.

[0037] Furthermore, since the enable terminal of the fuel gauge unit is connected to the second terminal of the first switching unit, when the first switching unit is turned off, the enable terminal of the fuel gauge unit will lose power and become ineffective, causing the fuel gauge unit to enter a low-power sleep state. This reduces the power consumption of the fuel gauge unit and further slows down the battery's discharge rate, thereby extending the battery's lifespan.

[0038] In this way, the battery life can be extended as much as possible, and the possibility of safety problems such as battery bulging and leakage can be reduced. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of the first over-discharge protection control circuit provided in the embodiments of this application;

[0041] Figure 2 This is a schematic diagram of the structure of the second over-discharge protection control circuit provided in the embodiments of this application;

[0042] Figure 3 This is a schematic diagram of the structure of the third over-discharge protection control circuit provided in the embodiments of this application;

[0043] Figure 4 This is a schematic diagram of the structure of the fourth over-discharge protection control circuit provided in the embodiments of this application;

[0044] Figure 5 This is a schematic diagram of the structure of the fifth over-discharge protection control circuit provided in the embodiments of this application;

[0045] Figure 6 A schematic diagram of the sixth over-discharge protection control circuit provided in the embodiments of this application;

[0046] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0050] In the description of this application, it should be noted that the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0051] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0052] In related technologies, when the fuel gauge detects that the battery voltage is lower than the over-discharge protection value, the corresponding processing unit controls the discharge circuit to close, thereby disconnecting the transmission path of the battery to external devices and reducing most of the battery's power consumption. At this time, the voltage is generally 2.5V or lower.

[0053] However, this method results in the battery being over-discharged when the discharge circuit is closed. Prolonged exposure to this state can shorten battery life or cause issues such as bulging and leakage. Furthermore, the fuel gauge still consumes power in this state, leading to a continuous decrease in the battery cell voltage, which also shortens battery life.

[0054] To address this, this application provides an over-discharge protection control circuit, which includes a first switching unit, a fuel gauge, a sampling control unit, and a first control unit. Specifically, the first terminal of the first switching unit is connected to the positive terminal of the battery, the second terminal of the first switching unit is connected to the positive terminal of an external device and the enable terminal of the fuel gauge unit, and the third terminal of the first switching unit is connected to the first terminal of the first control unit. The sampling terminal of the fuel gauge unit is connected to the positive terminal of the battery and ground, and the control terminal of the fuel gauge unit is connected to the first terminal of the sampling control unit. The second terminal of the sampling control unit is connected to the positive terminal of the battery, and the third terminal of the sampling control unit is connected to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit. The third terminal of the first control unit is connected to the positive terminal of the battery. Therefore, this application can not only shut down the battery's external discharge circuit before the actual battery voltage drops to the over-discharge protection voltage, but also put the fuel gauge unit into a low-power sleep state when the external discharge circuit is shut down. This can extend the battery's lifespan as much as possible and reduce the possibility of safety problems such as battery bulging and leakage.

[0055] This application uses an over-discharge protection control circuit applied in electronic devices as an example for illustration. However, it does not imply that this application's embodiments can only be applied to over-discharge protection of batteries in electronic devices.

[0056] Optionally, the electronic device can be any device with a battery, and this application embodiment does not limit this.

[0057] The over-discharge protection control circuit provided in the embodiments of this application will be explained in detail below.

[0058] Figure 1 A schematic diagram of an over-discharge protection control circuit provided in this application. See also... Figure 1 This application provides an over-discharge protection control circuit 100, which includes: a first switching unit 101, a power meter unit 102, a sampling control unit 103, and a first control unit 104.

[0059] The first end of the first switching unit 101 is used to connect to the positive terminal of the battery, the second end of the first switching unit 101 is used to connect to the positive terminal of the external device and the enable terminal of the fuel meter unit 102 respectively, and the third end of the first switching unit 101 is connected to the first end of the first control unit 104.

[0060] The sampling terminals of the fuel gauge unit 102 are used to connect to the positive terminal and the ground wire of the battery, respectively, and the control terminal of the fuel gauge unit 102 is connected to the first terminal of the sampling control unit 103.

[0061] The second terminal of the sampling control unit 103 is used to connect to the positive terminal of the battery, and the third terminal of the sampling control unit 103 is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit 104.

[0062] The third terminal of the first control unit 104 is used to connect to the positive terminal of the battery.

[0063] In this embodiment, the battery can be any type of battery, such as a lithium battery, a lead-acid battery, or any possible battery. This application embodiment does not limit this.

[0064] The positive terminal of the battery (e.g.) Figure 1 The B+ terminal shown is the end with the higher potential of the battery, and the negative terminal of the battery (e.g., B+). Figure 1 The B- shown is the end of the battery with the lower potential.

[0065] In this embodiment, the external device can be any possible power-consuming unit or a charging device, and this application embodiment does not limit it.

[0066] The first switch unit 101 is used to turn on or off under the control of the first control unit 104.

[0067] Optionally, the first switching unit 101 may include any controllable switch, such as a switching transistor or a relay, as long as it can ensure that the discharge circuit of the battery is cut off when the first switching unit 101 is turned off. This application embodiment does not limit this.

[0068] The power meter unit 102 is used to collect the output voltage of the battery and to control the sampling control unit 103 to turn on when the output voltage is less than a preset voltage.

[0069] Optionally, the output voltage may refer to the voltage that the battery outputs to the external device and the fuel gauge unit 102 in real time at the current moment.

[0070] Optionally, the preset voltage can be set by relevant technicians according to actual needs. Generally, the preset voltage is greater than the over-discharge protection voltage of the battery.

[0071] The over-discharge protection voltage is determined based on parameters such as the battery type and capacity. This over-discharge protection voltage can be used to indicate the voltage at which the battery will trigger over-discharge protection or enter an over-discharge state.

[0072] For example, if the over-discharge protection voltage is 2.5V, then the preset voltage could be 2.95V. This application does not limit this specific voltage.

[0073] The sampling control unit 103 is used to transmit the output voltage of the battery to the first control unit 104 when it is turned on, so as to pull up the voltage of the second terminal of the first control unit 104.

[0074] Optionally, the sampling control unit 103 may also include any possible controllable switch to facilitate control by the first control unit 104.

[0075] Understandably, when the output voltage is greater than or equal to the preset voltage, the fuel gauge unit 102 can control the sampling control unit 103 to turn off. Therefore, the sampling control unit 103 will not transmit the output voltage to the second terminal of the first control unit 104, and the voltage at the second terminal of the first control unit 104 will be the negative terminal voltage of the battery.

[0076] The first control unit 104 is used to control the first switching unit 101 to turn off when the voltage difference between the second and third terminals of the first control unit 104 is less than a first preset threshold.

[0077] In this embodiment, since the third terminal of the first control unit 104 is connected to the positive terminal of the battery, the voltage of the third terminal of the first control unit 104 is the voltage of the positive terminal of the battery, that is, the output voltage of the battery.

[0078] Since the second terminal of the first control unit 104 is connected to the third terminal of the sampling control unit 103 and the negative terminal of the battery respectively, the voltage at the second terminal of the first control unit 104 is the negative terminal voltage of the battery when the sampling control unit 103 is turned off. In this case, the voltage difference sampled between the second and third terminals of the first control unit 104 is the actual voltage of the battery.

[0079] Furthermore, when the sampling control unit 103 is turned on, the voltage at the second terminal of the first control unit 104 is pulled high by the output voltage transmitted by the sampling control unit 103. In this case, the voltage difference sampled between the second and third terminals of the first control unit 104 will be less than the actual voltage of the battery. In this way, the first control unit 104 can turn off the first switching unit 101 and cut off the battery's discharge circuit before the battery's output voltage drops to the battery's over-discharge protection voltage.

[0080] Optionally, the first preset threshold can be set by relevant technical personnel according to actual needs. Generally, the first preset threshold can be equal to or greater than the over-discharge protection voltage, and less than or equal to the preset voltage.

[0081] It is worth noting that, in order to better explain the over-discharge protection control circuit 100 provided in the embodiments of this application, the working principle of the circuit 100 is briefly described below:

[0082] When the battery's output voltage is high, i.e., greater than the preset voltage, the fuel gauge unit 102 controls the sampling control unit 103 to turn off. The sampling control unit 103 then prevents the battery's output voltage from being transmitted to the second terminal of the first control unit 104. At this time, the voltage at the second terminal of the first control unit 104 is the battery's negative terminal voltage, and the voltage at the third terminal of the first control unit 104 is the battery's positive terminal voltage. The voltage difference sampled by the first control unit 104 is the battery's actual voltage, which keeps the first switching unit 101 on, allowing the battery to discharge normally.

[0083] When the battery's output voltage is low, i.e., less than the preset voltage (for example, the battery's over-discharge protection voltage is 2.5V, the preset voltage is 2.95V, and the current output voltage is 2.94V), the fuel gauge unit 102 determines that the output voltage is less than the preset voltage. Therefore, the fuel gauge unit 102 controls the sampling control unit 103 to turn on. The sampling control unit 103 transmits the battery's output voltage to the second terminal of the first control unit 104 to raise the voltage at the second terminal of the first control unit 104. At this time, the voltage difference sampled between the second and third terminals of the first control unit 104 will be less than the actual battery voltage. Thus, before the actual battery voltage drops to the over-discharge protection voltage (the battery has not yet triggered over-discharge protection), the first switch unit 101 can be turned off to cut off the battery's external discharge circuit.

[0084] It should be noted that since the enable terminal of the fuel gauge unit 102 is connected to the second terminal of the first switch unit 101, when the first switch unit 101 is turned off, the enable terminal of the fuel gauge unit 102 will lose power and become ineffective, causing the fuel gauge unit 102 to enter a low-power sleep state. This reduces the power consumption of the fuel gauge unit 102 and further slows down the battery's discharge rate, thereby extending the battery's lifespan.

[0085] In this embodiment, the over-discharge protection control circuit 100 includes a first switching unit 101, a fuel gauge unit 102, a sampling control unit 103, and a first control unit 104. Specifically, the first terminal of the first switching unit 101 is connected to the positive terminal of the battery, the second terminal of the first switching unit 101 is connected to the positive terminal of an external device and the enable terminal of the fuel gauge unit 102, and the third terminal of the first switching unit 101 is connected to the first terminal of the first control unit 104. The sampling terminal of the fuel gauge unit 102 is connected to the positive terminal of the battery and ground, and the control terminal of the fuel gauge unit 102 is connected to the first terminal of the sampling control unit 103. The second terminal of the sampling control unit 103 is connected to the positive terminal of the battery, and the third terminal of the sampling control unit 103 is connected to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit 104. The third terminal of the first control unit 104 is connected to the positive terminal of the battery.

[0086] Specifically, when the fuel gauge unit 102 determines that the battery's output voltage is lower than the preset voltage, the fuel gauge unit 102 controls the sampling control unit 103 to turn on. The sampling control unit 103 transmits the battery's output voltage to the second terminal of the first control unit 104 to raise the voltage at the second terminal of the first control unit 104. At this time, the voltage difference sampled between the second and third terminals of the first control unit 104 will be less than the actual voltage of the battery. Thus, before the actual voltage of the battery drops to the over-discharge protection voltage (the battery has not yet triggered over-discharge protection), the first switch unit 101 can be turned off to cut off the battery's external discharge circuit.

[0087] Furthermore, since the enable terminal of the fuel gauge unit 102 is connected to the second terminal of the first switch unit 101, when the first switch unit 101 is turned off, the enable terminal of the fuel gauge unit 102 will lose power and become ineffective, causing the fuel gauge unit 102 to enter a low-power sleep state. This reduces the power consumption of the fuel gauge unit 102 and further slows down the battery's discharge rate, thereby extending the battery's lifespan.

[0088] In this way, the battery life can be extended as much as possible, and the possibility of safety problems such as battery bulging and leakage can be reduced.

[0089] In one possible implementation, see [link to relevant documentation]. Figure 2 The sampling control unit 103 includes at least: a first switching transistor Q1 and a first resistor R0.

[0090] The first terminal of the first switch transistor Q1 is connected to the first end of the first resistor R0, the second terminal of the first switch transistor Q1 is connected to the control terminal of the fuel meter unit 102, and the third terminal of the first switch transistor Q1 is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit 104.

[0091] The second end of the first resistor R0 is used to connect to the positive terminal of the battery.

[0092] The first switch Q1 is used to turn on under the control of the fuel meter unit 102 and transmit the output voltage of the battery to the first control unit 104.

[0093] Optionally, the first resistor R0 can be used as a pull-up resistor, which has the function of voltage division. The resistance value of the first resistor R0 can be set according to actual needs, and this embodiment does not limit it.

[0094] Optionally, the first switch Q1 can be an N-channel switch, such as an NMOS transistor. In this case, the first, second, and third terminals of the first switch Q1 can be the drain, gate, and source, respectively.

[0095] It is understandable that the voltage actually output by the first switch Q1 to the first control unit 104 is the voltage obtained by dividing the output voltage by the first resistor R0. Furthermore, the fuel gauge unit 102 can specifically output a high-level signal to the first switch Q1 to turn it on.

[0096] In one possible implementation, see [link to relevant documentation]. Figure 3 The first control unit 104 includes a first control chip U1 and a first capacitor C1.

[0097] The first sampling terminal of the first control chip U1 is used to connect to the positive terminal of the battery. The second sampling terminal of the first control chip U1 is used to connect to the third terminal of the sampling control unit 103, the negative terminal of the battery, and the negative terminal of the external device, respectively. The first control terminal of the first control chip U1 is connected to the third terminal of the first switching unit 101.

[0098] The first capacitor C1 is connected between the first sampling terminal and the second sampling terminal of the first control chip U1.

[0099] Optionally, the first control chip U1 can be any possible protection IC, and the first control chip U1 can have functions such as sampling, identification, calculation, processing, and control.

[0100] For example, the voltage difference sampled by the first control chip U1 is the difference between the voltage at the first sampling terminal VDD and the voltage at the second sampling terminal VSS. Furthermore, the first control terminal DO1 of the first control chip U1 can output a corresponding control signal to the third terminal of the first switching unit 101 to control the first switching unit 101 to be turned on or off.

[0101] In addition, the first control chip U1 may also have a corresponding detection pin TH to detect temperature or other parameters, and control the first switching unit 101 to turn off when it is confirmed that an abnormal parameter is detected.

[0102] In addition, the first control chip U1 may also include at least one overcurrent short circuit protection pin VM (not shown in the figure). For example, when the battery is short-circuited, the pin VM will be pulled low to a low voltage by the external circuit. At this time, the first control chip U1 will maintain the short circuit protection state and disconnect the first switching unit 101 until the battery eliminates the short circuit state. Then the pin VM will no longer maintain a low voltage, the short circuit protection will be released, and the first switching unit 101 will be turned on so that the battery can continue to work normally.

[0103] Optionally, the first capacitor C1 can be used as a filter capacitor to improve the accuracy of the voltage difference sampled by the first control unit 104 and to improve the stability and reliability of the circuit 100.

[0104] In one possible implementation, see [link to relevant documentation]. Figure 2 Circuit 100 also includes: a second resistor R1.

[0105] The first end of the second resistor R1 is connected to the second end of the first control unit 104 and the third end of the sampling control unit 103, respectively, and the second end of the second resistor R1 is connected to the negative terminal of the battery and the negative terminal of the external device, respectively.

[0106] Optionally, the second resistor R1 can be used as a voltage divider resistor.

[0107] Understandably, in this case, when the sampling control unit 103 is turned on, the voltage actually transmitted by the sampling control unit 103 to the second terminal of the first control unit 104 is the voltage after the second resistor R1 and the first resistor R0 divide the output voltage.

[0108] For example, suppose the voltage at the second terminal of the first control unit 104 is V. vss The output voltage of this battery is V. B+ So, V vss =V B+ *R1 / (R0+R1).

[0109] For example, V B+～B- = 2.95V, the over-discharge protection voltage or the first preset threshold is 2.5V, R1 = 1KΩ, R0 = 5.1KΩ, at this time V vss ≈0.467V, the voltage difference collected by the first control unit 104 = V B+ -V vss =2.483V < This over-discharge protection voltage can enable the first control unit 104 to control the first switching unit 101 to turn off.

[0110] In one possible implementation, see [link to relevant documentation]. Figure 4 The first switching unit 101 includes at least one second switching transistor Q2.

[0111] The first terminal of each second switch Q2 is used to connect to the positive terminal of the battery, the second terminal of each second switch Q2 is used to connect to the positive terminal of the external device, and the third terminal of each second switch Q2 is connected to the first terminal of the first control unit 104.

[0112] Furthermore, the second terminal of at least one of the second switching transistors Q2 is connected to the enable terminal of the fuel meter unit 102.

[0113] Optionally, the second switch Q2 can be an N-channel switch, such as an NMOS transistor. In this case, the first, second, and third terminals of the second switch Q2 can be the drain, source, and gate, respectively.

[0114] In this embodiment, the second terminal of each second switch Q2 can be connected to the positive terminal of the same external device or to the positive terminal of different external devices. This application embodiment does not limit this.

[0115] It should be noted that, Figure 4 The example described uses two second switching transistors Q2 in the first switching unit 101, but this does not mean that the circuit 100 provided in this embodiment can only include two second switching transistors Q1. In practical applications, if it is necessary for the circuit 100 to withstand a larger current, three or more second switching transistors Q1 can be provided; if the circuit 100 only needs to withstand a smaller power, only one second switching transistor Q1 can be provided. Specific adjustments can be made according to actual needs, and this embodiment does not limit this.

[0116] In one possible way, see Figure 5 The fuel meter unit 102 may also include a fuel meter U0, a resistor Ra, a resistor Rb, a capacitor Ca, a capacitor Cb, a resistor Rc, and a capacitor Rc.

[0117] The fuel meter U0 has a sampling terminal BAT, a sampling terminal BAT_SNS, an enable terminal CE, and a control terminal PULS. The specific connection relationships are as follows: Figure 5 As shown, the embodiments of this application will not be described in detail here.

[0118] In addition, the fuel gauge U0 may also have any possible functional pins such as detection pin SPR, detection pin SPN, detection pin TS, clock pin SCL, and data transmission pin SDA / HDQ. Furthermore, the fuel gauge unit 102 may also be equipped with corresponding resistors, capacitors, TVS diodes, and other devices to ensure that each pin and / or port in the fuel gauge U0 correctly performs its corresponding function. This application embodiment does not limit this.

[0119] It should be noted that when the battery's output voltage is lower than the aforementioned preset voltage, the fuel gauge U0 will trigger over-discharge protection, thereby shutting down the first switching unit 101 through the sampling control unit 103 and the first control unit 101. The fuel gauge U0 will also stop being enabled and enter a low-power sleep state, significantly reducing the overall circuit power consumption. Furthermore, due to the presence of capacitor Cc, the control terminal PULS will remain at a high level, thus maintaining the stable low power consumption of circuit 100.

[0120] In one possible implementation, see [link to relevant documentation]. Figure 6 The first switching unit 101 further includes at least one third switching transistor Q3, the number of which is the same as the number of second switching transistors Q2.

[0121] The first terminal of the third switch Q3 is connected to the positive terminal of the battery, the second terminal of the third switch Q3 is connected to the first terminal of the second switch Q2, and the third terminal of the third switch Q3 is connected to the fourth terminal of the first control unit 104.

[0122] Optionally, the third switch Q3 can be an N-channel switch, such as an NMOS transistor. In this case, the first, second, and third terminals of the third switch Q3 can be the source, drain, and gate, respectively.

[0123] from Figure 6 It can be seen that the fourth terminal of the first control unit 104 can be Figure 6 The CO1 terminal of the first control chip U1 shown.

[0124] Furthermore, each third switch Q3 corresponds to a second switch Q2. That is, if the second terminal of a third switch Q3 is connected to the first terminal of a second switch Q2, it indicates that the third switch Q3 and the second switch Q2 are corresponding, and the third switch Q3 and the second switch Q2 can serve as a discharge circuit for the battery.

[0125] Specifically, the third switch Q3 can be used as a charging protection switch, and the second switch Q2 can be used as a discharging protection switch. That is, when the battery is overcharged or other problems occur during charging, the first control unit 104 can output a corresponding shutdown signal to the third switch Q3 through the CO1 terminal.

[0126] It is worth noting that since the second switch Q2 and the third switch Q3 have body diodes, leakage current may occur when the second switch Q2 or the third switch Q3 is turned off. However, in this embodiment, the drain of the third switch Q3 is connected to the drain of the second switch Q2, which can prevent leakage current. This improves the safety of circuit 100.

[0127] In one possible implementation, see [link to previous section] Figure 6 The circuit 100 also includes a second switching unit 105 and a second control unit 106.

[0128] The first end of the second switching unit 105 is used to connect to the positive terminal of the battery, the second end of the second switching unit 105 is connected to the first end of the first switching unit 101, and the third end of the second switching unit 105 is connected to the first end of the second control unit 106.

[0129] The second terminal of the second control unit 106 is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit 104, respectively, and the third terminal of the second control unit 106 is used to connect to the positive terminal of the battery.

[0130] The second switch unit 105 is used to turn on or off under the control of the second control unit 106.

[0131] Optionally, the second switching unit 105 may include any controllable switch, such as a switching transistor or a relay, as long as it ensures that the discharge circuit of the battery can be cut off when the second switching unit 105 is turned off. This application embodiment does not limit this.

[0132] The second control unit 106 is used to control the second switching unit 105 to turn off when the voltage difference between the second and third terminals of the second control unit 106 is less than a second preset threshold.

[0133] Optionally, the second preset threshold can be set by relevant technical personnel according to actual needs. Generally, the second preset threshold can be equal to or less than the first preset threshold, and greater than or equal to the over-discharge protection voltage. The second preset threshold can also be any other possible value, and this application embodiment does not limit it.

[0134] In this embodiment, since the third terminal of the second control unit 106 is connected to the positive terminal of the battery, the voltage of the third terminal of the second control unit 106 is the voltage of the positive terminal of the battery, that is, the output voltage of the battery.

[0135] Since the second terminal of the second control unit 106 is used to connect to the negative terminal of the battery and the negative terminal of the external device, the voltage at the second terminal of the second control unit 106 is the negative terminal voltage of the battery. That is, the voltage difference sampled between the second and third terminals of the second control unit 106 is the actual voltage of the battery.

[0136] As can be seen, since the voltage difference sampled between the second and third terminals of the second control unit 106 is equal to the actual voltage of the battery, the second control unit 106 can turn off the second switching unit 105 to cut off the battery's discharge circuit when the battery's output voltage drops to the battery's over-discharge protection voltage.

[0137] It is worth noting that if the first switching unit 101, the fuel gauge unit 102, the sampling control unit 103 and / or the first control unit 104 malfunction and are unable to disconnect the battery's discharge circuit before the battery's output voltage drops to the battery's over-discharge protection voltage, then the second control unit 106 can also disconnect the battery's discharge circuit by turning off the second switching unit 105 when the battery drops to the over-discharge protection voltage or before it drops to the over-discharge protection voltage.

[0138] However, if the first switch unit 101, the fuel gauge unit 102, the sampling control unit 103 and the first control unit 104 are working normally, then when the first control unit 104 controls the first switch unit 101 to turn off, the actual voltage of the battery will be higher than the over-discharge protection voltage or the second preset threshold. Therefore, when the first switch unit 101 can be turned off normally, the second control unit 106 generally will not control the second switch unit 105 to operate.

[0139] This provides dual protection for the battery, improving the reliability and stability of circuit 100.

[0140] In one possible implementation, see [link to relevant documentation]. Figure 6 The second control unit 106 includes: a second control chip U2 and a second capacitor C2.

[0141] The first sampling terminal of the second control chip U2 is used to connect to the positive terminal of the battery, and the second sampling terminal of the second control chip U2 is used to connect to the negative terminal of the battery and the negative terminal of the external device, respectively. The first control terminal of the second control chip U2 is connected to the third terminal of the second switching unit 105.

[0142] The second capacitor C2 is connected between the first sampling terminal and the second sampling terminal of the second control chip U2.

[0143] Optionally, the second control chip U2 can be any possible protection IC, and the second control chip U2 can have functions such as sampling, identification, calculation, processing, and control.

[0144] For example, the voltage difference sampled by the second control chip U2 is the difference between the voltage at the first sampling terminal VDD2 and the voltage at the second sampling terminal VSS2. Furthermore, the first control terminal DO2 of the second control chip U2 can output a corresponding control signal to the third terminal of the second switching unit 105 to control the second switching unit 105 to be turned on or off.

[0145] In addition, the second control chip U2 may also have a corresponding detection pin TH to detect temperature or other parameters, and control the second switching unit 105 to turn off when it is confirmed that an abnormal parameter is detected.

[0146] In addition, the second control chip U2 may also include at least one overcurrent short circuit protection pin VM (not shown in the figure). For example, when the battery is short-circuited, the pin VM will be pulled low to a low voltage by the external circuit. At this time, the second control chip U2 will maintain the short circuit protection state and disconnect the second switching unit 105 until the battery eliminates the short circuit state. Then the pin VM will no longer maintain a low voltage, the short circuit protection will be released, and the second switching unit 105 will be turned on so that the battery can continue to work normally.

[0147] Optionally, the second capacitor C2 can be used as a filter capacitor to improve the accuracy of the voltage difference sampled by the second control unit 106 and to improve the stability and reliability of the circuit 100.

[0148] It is worth noting that, under normal circumstances, if the first control chip U1 takes action in response to any of the aforementioned abnormal situations, the second control chip U2 may not take any action. That is, the second control chip U2 may take action only after the corresponding function of the first control chip U1 fails. This application embodiment does not limit this aspect.

[0149] In one possible implementation, see [link to relevant documentation]. Figure 6 Circuit 100 also includes a third resistor R2.

[0150] The first end of the third resistor R2 is connected to the second end of the second control unit 106, and the second end of the third resistor R2 is connected to the negative terminal of the battery and the negative terminal of the external device, respectively.

[0151] Optionally, the third resistor R2 can be used as a voltage divider resistor.

[0152] In one possible implementation, see [link to previous section] Figure 6 The second switching unit 105 includes at least one fourth switching transistor Q4.

[0153] The first terminal of the fourth switch Q4 is connected to the positive terminal of the battery, the second terminal of the fourth switch Q4 is connected to the first terminal of the first switch unit 101, and the third terminal of the fourth switch Q4 is connected to the first terminal of the second control unit 106.

[0154] Optionally, the fourth switch Q4 can be an N-channel switch, such as an NMOS transistor. In this case, the first, second, and third terminals of the fourth switch Q4 can be the drain, source, and gate, respectively.

[0155] It should be noted that, Figure 4 The example described uses two fourth switching transistors Q4 in the second switching unit 105, but this does not mean that the circuit 100 provided in this embodiment can only include two fourth switching transistors Q4. In practical applications, if the circuit 100 needs to withstand a larger current, three or more fourth switching transistors Q4 can be provided; if the circuit 100 only needs to withstand a smaller power, only one fourth switching transistor Q4 can be provided. Specific adjustments can be made according to actual needs, and this embodiment does not limit this.

[0156] In one possible implementation, see [link to previous section] Figure 6 The second switching unit 105 further includes at least one fifth switching transistor Q5, the number of which is the same as the number of the fourth switching transistor Q4.

[0157] The first terminal of the fifth switch Q5 is connected to the positive terminal of the battery, the second terminal of the fifth switch Q5 is connected to the first terminal of the fourth switch Q4, and the third terminal of the fifth switch Q5 is connected to the fourth terminal of the second control unit 106.

[0158] Optionally, the fifth switch Q5 can be an N-channel switch, such as an NMOS transistor. In this case, the first, second, and third terminals of the fifth switch Q5 can be the source, drain, and gate, respectively.

[0159] from Figure 6 It can be seen that the fourth terminal of the second control unit 106 can be Figure 6 The CO2 terminal of the second control chip U2 shown.

[0160] Furthermore, each fifth switch Q5 corresponds to a fourth switch Q4. That is, if the second terminal of a fifth switch Q5 is connected to the first terminal of a fourth switch Q4, it indicates that the fifth switch Q5 and the fourth switch Q4 are corresponding, and the fifth switch Q5 and the fourth switch Q4 can serve as a discharge circuit for the battery.

[0161] Specifically, the fifth switch Q5 can be used as a charging protection switch, and the fifth switch Q5 can also be used as a discharging protection switch. That is, when the battery is overcharged or other problems occur during the charging process, the second control unit 106 can output a corresponding shutdown signal to the fifth switch Q5 through the CO2 terminal.

[0162] It is worth noting that since the fourth switch Q4 and the fifth switch Q5 have body diodes, leakage current may occur when the fourth switch Q4 or the fifth switch Q5 is turned off. However, in this embodiment, the drain of the fifth switch Q5 is connected to the drain of the fourth switch Q4, which can prevent leakage current. This improves the safety of circuit 100.

[0163] In one possible configuration, circuit 100 may also include a switching transistor Qc and a resistor Rd.

[0164] Optionally, resistor Rd can be used as a current-limiting resistor to protect the switching transistor Qc.

[0165] Understandably, the function of the switching transistor Qc is to prevent reverse charging. When the charger is connected in reverse between the P+ and P- terminals, the switching transistor Qc will conduct, pulling down the voltage at the DO1 terminal of the first control unit 104, thereby turning off the first switching unit 101. In this way, it can provide reverse charging protection.

[0166] In one possible approach, circuit 100 may also include capacitors Cd and Ce, which can serve as filter capacitors to improve the stability of circuit 100.

[0167] It should be noted that, in this embodiment of the application, when the first control unit 104 controls the first switch unit 101 to be turned off, each of the second switch transistors Q2 is turned on in the charging direction of the battery, so the battery can be charged.

[0168] When the battery is charging, V P+ =V 充电器 =V CE That is, the enable terminal of the fuel gauge unit 102 must be at a high level, and the fuel gauge unit 102 will automatically resume operation when the battery voltage V B+～B- When the voltage exceeds 2.95V (i.e., the battery output voltage is greater than the preset voltage mentioned above), the control terminal PULS of the fuel gauge unit 102 returns to a low level, causing the sampling control unit 103 to disconnect, thereby causing V... VSS =VB-, the voltage difference sampled by the first control unit 104 =V VDD ~V VSS =VB+-VB-, the first control unit 104 controls the first switch unit 101 to conduct, so that the circuit 100 resumes normal operation.

[0169] As can be seen, the circuit 100 provided in this application embodiment also has the function of automatically releasing the low power consumption state when the battery voltage returns to normal, which improves the practicality of the circuit 100.

[0170] In one possible approach, a switching transistor of the same specification can be connected in parallel between the source and drain of each of the aforementioned second switching transistors Q2 (or each of the third switching transistors Q3, or each of the fourth switching transistors Q4, or each of the fifth switching transistors Q5), and the direction of the parallel-connected switching transistors is the same as the direction of the original switching transistors, so as to further increase the current or power value that each discharge circuit can carry. This application does not limit this aspect.

[0171] The following describes an electronic device including the over-discharge protection control circuit provided in this application. The specific implementation process and technical effects are described above and will not be repeated below.

[0172] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. See also... Figure 7 The electronic device includes at least the over-discharge protection control circuit 100 provided in any of the above embodiments.

[0173] Optionally, see [link to relevant documentation] Figure 7 The electronic device may also include a battery 200, the positive and negative terminals of which are connected to the over-discharge protection control circuit 100, respectively. See [link to circuit diagram] for specific connection details. Figure 7 As shown, the embodiments of this application will not be described in detail here.

[0174] The aforementioned electronic device includes the over-discharge protection control circuit 100 provided in the foregoing embodiments. The electronic device and the over-discharge protection control circuit 100 belong to the same design concept, and their implementation principles and technical effects are similar, so they will not be described again here.

[0175] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0176] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An over-discharge protection control circuit, characterized in that, The circuit includes: a first switching unit, a fuel meter unit, a sampling control unit, and a first control unit; The first terminal of the first switching unit is used to connect to the positive terminal of the battery, the second terminal of the first switching unit is used to connect to the positive terminal of the external device and the enable terminal of the fuel gauge unit respectively, and the third terminal of the first switching unit is connected to the first terminal of the first control unit; the first switching unit is used to turn on or off under the control of the first control unit. The sampling terminals of the fuel gauge unit are respectively connected to the positive terminal and the ground wire of the battery, and the control terminal of the fuel gauge unit is connected to the first terminal of the sampling control unit; the fuel gauge unit is used to collect the output voltage of the battery, and to control the sampling control unit to turn on when the output voltage is less than a preset voltage; the preset voltage is greater than the over-discharge protection voltage of the battery; The second terminal of the sampling control unit is used to connect to the positive terminal of the battery, and the third terminal of the sampling control unit is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit, respectively; the sampling control unit is used to transmit the output voltage of the battery to the first control unit when it is turned on, so as to pull up the voltage of the second terminal of the first control unit. The third terminal of the first control unit is used to connect to the positive terminal of the battery; the first control unit is used to control the first switching unit to turn off when the voltage difference between the second and third terminals of the first control unit is less than a first preset threshold.

2. The over-discharge protection control circuit as described in claim 1, characterized in that, The sampling control unit includes at least: a first switching transistor and a first resistor; The first terminal of the first switching transistor is connected to the first end of the first resistor, the second terminal of the first switching transistor is connected to the control terminal of the fuel gauge unit, and the third terminal of the first switching transistor is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit. The second end of the first resistor is used to connect to the positive terminal of the battery; The first switch is turned on under the control of the fuel gauge unit and transmits the output voltage of the battery to the first control unit.

3. The over-discharge protection control circuit as described in claim 1, characterized in that, The first control unit includes: a first control chip and a first capacitor; The first sampling terminal of the first control chip is used to connect to the positive terminal of the battery, and the second sampling terminal of the first control chip is used to connect to the third terminal of the sampling control unit, the negative terminal of the battery and the negative terminal of the external device, respectively. The first control terminal of the first control chip is connected to the third terminal of the first switching unit. The first capacitor is connected between the first sampling terminal and the second sampling terminal of the first control chip.

4. The over-discharge protection control circuit as described in claim 1, characterized in that, The first switching unit includes: at least one second switching transistor; The first terminal of each of the second switching transistors is used to connect to the positive terminal of the battery, the second terminal of each of the second switching transistors is used to connect to the positive terminal of the external device, the third terminal of the second switching transistor is connected to the first terminal of the first control unit, and at least one of the second switching transistors is connected to the enable terminal of the fuel gauge unit.

5. The over-discharge protection control circuit as described in claim 4, characterized in that, The first switching unit further includes: at least one third switching transistor, the number of which is the same as the number of the second switching transistors; The first terminal of the third switch is connected to the positive terminal of the battery, the second terminal of the third switch is connected to the first terminal of the second switch, and the third terminal of the third switch is connected to the fourth terminal of the first control unit.

6. The over-discharge protection control circuit as described in claim 1, characterized in that, The circuit also includes: a second switching unit and a second control unit; The first end of the second switching unit is used to connect to the positive terminal of the battery, the second end of the second switching unit is connected to the first end of the first switching unit, and the third end of the second switching unit is connected to the first end of the second control unit; the second switching unit is used to turn on or off under the control of the second control unit. The second terminal of the second control unit is used to connect to the negative terminal of the battery, the negative terminal of the external device, and the second terminal of the first control unit, respectively. The third terminal of the second control unit is used to connect to the positive terminal of the battery. The second control unit is used to control the second switching unit to turn off when the voltage difference between the second terminal and the third terminal of the second control unit is less than a second preset threshold.

7. The over-discharge protection control circuit as described in claim 6, characterized in that, The second control unit includes: a second control chip and a second capacitor; The first sampling terminal of the second control chip is used to connect to the positive terminal of the battery, the second sampling terminal of the second control chip is used to connect to the negative terminal of the battery and the negative terminal of the external device, and the first control terminal of the second control chip is connected to the third terminal of the second switching unit. The second capacitor is connected between the first sampling terminal and the second sampling terminal of the second control chip.

8. The over-discharge protection control circuit as described in claim 6, characterized in that, The second switching unit includes: at least one fourth switching transistor; The first terminal of the fourth switch is connected to the positive terminal of the battery, the second terminal of the fourth switch is connected to the first terminal of the first switch unit, and the third terminal of the fourth switch is connected to the first terminal of the second control unit.

9. The over-discharge protection control circuit as described in claim 8, characterized in that, The second switching unit further includes: at least one fifth switching transistor, the number of which is the same as the number of the fourth switching transistor; The first terminal of the fifth switch is connected to the positive terminal of the battery, the second terminal of the fifth switch is connected to the first terminal of the fourth switch, and the third terminal of the fifth switch is connected to the fourth terminal of the second control unit.

10. An electronic device, characterized in that, The electronic device includes at least the over-discharge protection control circuit as described in any one of claims 1 to 9.

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