A battery step discharge circuit and electronic equipment

Abstract

The present application provides a battery step discharge circuit and electronic equipment, including: a reference voltage circuit, a primary discharge circuit, a secondary discharge circuit, a tertiary discharge circuit, a quaternary discharge circuit, a first switch, a second switch, and a third switch; the reference voltage circuit outputs a first reference voltage, a second reference voltage, and a third reference voltage; the primary discharge circuit discharges the voltage of the battery to be discharged to the first reference voltage; the secondary discharge circuit discharges the voltage of the battery to be discharged to an adjustable voltage range; the tertiary discharge circuit discharges the voltage of the battery to be discharged to the second reference voltage; the quaternary discharge circuit discharges the voltage of the battery to be discharged to the third reference voltage; the first switch, the second switch, and the third switch are used to control the conduction or disconnection between adjacent discharge circuits. The cascade relationship between the discharge circuits at each level is controlled by the states of the first switch, the second switch, and the third switch, and the fully charged battery is discharged to different voltages to obtain batteries with different voltages.

Description

Technical Field

[0001] The present application relates to the technical field of battery detection, and in particular to a battery step discharge circuit and electronic equipment. Background Art

[0002] For mobile phones running on the Qualcomm platform, it is necessary to conduct charging experiments on the lithium batteries in the mobile phones. Usually, it is necessary to verify the four stages of the charging process: trickle charge, pre-charge, fast charge, and taper. Different voltage lithium batteries are required for verification of different stages. For example, the required lithium battery voltage is 1.5V (lower than 2.1V) when the trickle charge stage is converted to the pre-charge stage verification, and the required lithium battery voltage is 3V~3.4V when the pre-charge stage is converted to the fast charge stage. During the test, the conversion voltage threshold can be set by software.

[0003] In order to obtain lithium batteries with different voltages to meet the needs of product testing, lithium batteries with different voltages can be obtained by discharging fully charged lithium batteries. In practical applications, different discharge methods can be used, for example, APK discharge, that is, running the application software in the mobile phone system to quickly consume the power of the mobile phone lithium battery. APK discharge can only discharge the voltage of the lithium battery to the shutdown voltage of 3.4V. The lithium battery can also be directly connected to the discharge power resistor for discharge. For batteries with protection boards, the over-discharge protection voltage is generally around 3V. When the lithium battery voltage is discharged to 3V, it will be cut off. The cell voltage of the lithium battery cannot continue to drop below 2.1V. Usually, the protection board is removed and the discharge continues. When a high-power discharge resistor is used for discharge, it is easy to cause the cell to be over-discharged, destroying the reversibility of the positive and negative active materials of the lithium battery, causing the electrolyte to decompose, the negative electrode lithium to deposit, and the resistance to increase. Even if it is recharged, it can only be partially restored, and the battery capacity of the lithium battery will be significantly attenuated. You can also use a load meter for discharge and set the load meter to CV (constant voltage) mode. When the difference between the voltage and CV value of the lithium battery is large (due to discharge, the CV value is less than the voltage of the lithium battery), the discharge current will be very large. When the discharge current exceeds the maximum discharge current of the lithium battery, it will cause damage to the lithium battery. Therefore, during the discharge process, the CV value needs to be adjusted manually, which is time-consuming and labor-intensive. Summary of the invention

[0004] The present application provides a battery step discharge circuit and electronic equipment to obtain lithium batteries with different voltages. The specific technical solution is as follows:

[0005] In a first aspect, the present application provides a battery step discharge circuit, the battery step discharge circuit comprising: a reference voltage circuit, a primary discharge circuit, a secondary discharge circuit, a tertiary discharge circuit, a quaternary discharge circuit, a first switch, a second switch, and a third switch;

[0006] The reference voltage circuit is electrically connected to the primary discharge circuit, the secondary discharge circuit, the tertiary discharge circuit, and the quaternary discharge circuit, respectively; the first switch is electrically connected to the primary discharge circuit and the secondary discharge circuit, respectively; the second switch is electrically connected to the secondary discharge circuit and the tertiary discharge circuit, respectively; the third switch is electrically connected to the tertiary discharge circuit and the quaternary discharge circuit, respectively;

[0007] The reference voltage circuit is used to output a first reference voltage, a second reference voltage and a third reference voltage, wherein the first reference voltage is higher than the second reference voltage and the third reference voltage, and the second reference voltage is higher than the third reference voltage;

[0008] The primary discharge circuit is used for discharging the voltage of the battery to be discharged to the first reference voltage when the voltage of the battery to be discharged is higher than the first reference voltage;

[0009] The secondary discharge circuit is used for discharging the voltage of the battery to be discharged to the voltage interval when the voltage of the battery to be discharged is lower than the first reference voltage and higher than the minimum value of the voltage interval;

[0010] The three-stage discharge circuit is used for discharging the voltage of the battery to be discharged to the second reference voltage when the voltage of the battery to be discharged is higher than the second reference voltage and lower than the minimum value of the voltage interval;

[0011] The four-stage discharge circuit is used for discharging the voltage of the battery to be discharged to the third reference voltage when the voltage of the battery to be discharged is higher than the third reference voltage and lower than the second reference voltage;

[0012] The first switch is used to control the conduction or disconnection between the primary discharge circuit and the secondary discharge circuit;

[0013] The second switch is used to control the conduction or disconnection between the secondary discharge circuit and the tertiary discharge circuit;

[0014] The third switch is used to control the conduction or disconnection between the third-level discharge circuit and the fourth-level discharge circuit.

[0015] In a possible design, the primary discharge circuit includes: a first voltage comparator, a first voltage regulator, and a first variable resistor;

[0016] The non-inverting input terminal of the first voltage comparator is electrically connected to the positive electrode of the battery to be discharged, the first end of the first switch, and the input terminal of the first voltage regulator, respectively; the inverting input terminal of the first voltage comparator is connected to the first reference voltage; and the output terminal of the first voltage comparator is electrically connected to the enable terminal of the first voltage regulator and the secondary discharge circuit, respectively;

[0017] The output end of the first regulator is electrically connected to the first end of the first variable resistor, and the second end of the first variable resistor is grounded.

[0018] In a possible design, the secondary discharge circuit includes: a second voltage comparator, a second voltage regulator, a second variable resistor, a first NOT gate, a first AND gate, a first resistor, and a fifth variable resistor;

[0019] The first end of the fifth variable resistor is connected to the first reference voltage, and the second end of the fifth variable resistor is electrically connected to the first end of the first resistor and the inverting input end of the second voltage comparator respectively;

[0020] The second end of the first resistor is grounded;

[0021] The non-inverting input terminal of the second voltage comparator is electrically connected to the second terminal of the first switch, the first terminal of the second switch, and the input terminal of the second regulator respectively, and the output terminal of the second voltage comparator is electrically connected to the first input terminal of the first AND gate;

[0022] The input end of the first NOT gate is electrically connected to the first-stage discharge circuit, the output end of the first NOT gate is electrically connected to the second input end of the first AND gate, and the output end of the first AND gate is electrically connected to the three-stage discharge circuit and the enable end of the second regulator respectively;

[0023] The output end of the second regulator is electrically connected to the first end of the second variable resistor, and the second end of the second variable resistor is grounded.

[0024] In a possible design, the three-stage discharge circuit includes: a third voltage comparator, a third voltage regulator, a third variable resistor, a second NOT gate, and a second AND gate;

[0025] The inverting input terminal of the third voltage comparator is connected to the second reference voltage, the non-inverting input terminal of the third voltage comparator is electrically connected to the second end of the second switch, the first end of the third switch, and the input terminal of the third regulator respectively, and the output terminal of the third voltage comparator is electrically connected to the first input terminal of the second AND gate;

[0026] The input end of the second NOT gate is electrically connected to the secondary discharge circuit, the output end of the second NOT gate is electrically connected to the second input end of the second AND gate, and the output end of the second AND gate is electrically connected to the enable end of the fourth discharge circuit and the third regulator respectively;

[0027] The output end of the third regulator is electrically connected to the first end of the third variable resistor, and the second end of the third variable resistor is grounded.

[0028] In a possible design, the four-stage discharge circuit includes: a fourth voltage comparator, a fourth voltage regulator, a fourth variable resistor, a third NOT gate, and a third AND gate;

[0029] The inverting input terminal of the fourth voltage comparator is connected to the third reference voltage, the non-inverting input terminal of the fourth voltage comparator is electrically connected to the second terminal of the third switch and the input terminal of the fourth voltage regulator respectively, and the output terminal of the fourth voltage comparator is electrically connected to the first input terminal of the third AND gate;

[0030] The input end of the third NOT gate is electrically connected to the three-stage discharge circuit, the output end of the third NOT gate is electrically connected to the second input end of the third AND gate, and the output end of the third AND gate is electrically connected to the enable end of the fourth regulator;

[0031] The output end of the fourth regulator is electrically connected to the first end of the fourth variable resistor, and the second end of the fourth variable resistor is grounded.

[0032] In a possible design, the first voltage regulator and the second voltage regulator are step-up or step-down power supply chips.

[0033] In a possible design, a resistance value of the second variable resistor is greater than a resistance value of the first variable resistor.

[0034] In a possible design, the third regulator and the fourth regulator are low dropout linear regulators.

[0035] In a possible design, the voltage range is 2.7V to 3.6V.

[0036] In a second aspect, the present application provides an electronic device, comprising: a battery step discharge circuit as described in the first aspect.

[0037] Beneficial effects of the embodiments of the present application:

[0038] In an embodiment of the present application, the battery can be discharged to different voltages using a primary discharge circuit, a secondary discharge circuit, a tertiary discharge circuit, and a quaternary discharge circuit. The cascade relationship between the primary discharge circuit, the secondary discharge circuit, the tertiary discharge circuit, and the quaternary discharge circuit can be controlled by controlling the states of the first switch, the second switch, and the third switch, and the fully charged battery can be discharged to different voltages to obtain lithium batteries with different voltages to meet the needs of battery performance testing, thereby saving labor costs.

[0039] The beneficial effects provided in the above-mentioned second aspect and various possible designs of the above-mentioned second aspect can refer to the beneficial effects brought about by the above-mentioned first aspect and various possible implementation methods of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0041] Figure 1 Schematic diagram of the four stages of the charging process;

[0042] Figure 2 A schematic diagram of a battery step discharge circuit structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] In this application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c alone can represent: a, b, c, a and b, a and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0044] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0045] The terms "connected" and "connected" should be understood in a broad sense. For example, the "connected" or "connected" of a circuit structure can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] See also Figure 1 , Figure 1 It is a schematic diagram of the four stages of the charging process, such as Figure 1 As shown in the figure, the four stages of the charging process include trickle charge (Trickle), pre-charge (Pre-Charge), fast charge (Fast-Charge) and slow charge (Taper). The charging current of each stage is different. The charging current of the trickle charge stage (Trickle) is 50mA, the charging current of the pre-charge stage (Pre-Charge) is 300mA, the charging current of the fast charge stage (Fast-Charge) is 100mA~8A, and the charging current of the slow charge stage (Taper) is gradually reduced. During the whole charging process, the voltage of the lithium battery tends to increase. In the slow charge stage (Taper), the voltage of the lithium battery will no longer increase after being fully charged.

[0047] Different voltages of lithium batteries are required for verification at different stages. Several methods for discharging fully charged lithium batteries provided in the related art can obtain lithium batteries of different voltages, but there are problems of damaging the battery and consuming time and effort. To this end, the present application provides a battery step discharge circuit to obtain lithium batteries of different voltages.

[0048] See also Figure 2 , Figure 2 A battery step discharge circuit 1000 provided in an embodiment of the present application is as follows: Figure 2As shown, the circuit may include: a reference voltage circuit 100, a primary discharge circuit 200, a secondary discharge circuit 300, a tertiary discharge circuit 400, a quaternary discharge circuit 500, a first switch S1, a second switch S2, and a third switch S3.

[0049] The reference voltage circuit 100 is electrically connected to the primary discharge circuit 200, the secondary discharge circuit 300, the tertiary discharge circuit 400, and the fourth discharge circuit 500, respectively; the first switch S1 is electrically connected to the primary discharge circuit 200 and the secondary discharge circuit 300, respectively; the second switch S2 is electrically connected to the secondary discharge circuit 300 and the tertiary discharge circuit 400, respectively; the third switch S3 is electrically connected to the tertiary discharge circuit 400 and the fourth discharge circuit 500, respectively.

[0050] The reference voltage circuit 100 is used to output a first reference voltage of 3.6V, a second reference voltage of 2.1V and a third reference voltage of 1.5V, wherein the first reference voltage of 3.6V is higher than the second reference voltage of 2.1V and the third reference voltage of 1.5V, and the second reference voltage of 2.1V is higher than the third reference voltage of 1.5V.

[0051] The primary discharge circuit 200 is used for discharging the voltage of the battery B1 to be discharged to the first reference voltage 3.6V when the voltage of the battery B1 to be discharged is higher than the first reference voltage 3.6V.

[0052] The secondary discharge circuit 300 is used for discharging the voltage of the battery B1 to be discharged to the voltage interval when the voltage of the battery B1 to be discharged is lower than the first reference voltage 3.6V and higher than the minimum value of the voltage interval.

[0053] The three-stage discharge circuit 400 is used for discharging the voltage of the battery B1 to be discharged to the second reference voltage 2.1V when the voltage of the battery B1 to be discharged is higher than the second reference voltage 2.1V and lower than the minimum value of the voltage interval.

[0054] The four-stage discharge circuit 500 is used for discharging the voltage of the battery to be discharged to a third reference voltage of 1.5V when the voltage of the battery to be discharged B1 is higher than the third reference voltage of 1.5V and lower than the second reference voltage of 2.1V.

[0055] The first switch is used to control the conduction or disconnection between the primary discharge circuit and the secondary discharge circuit.

[0056] The second switch is used to control the conduction or disconnection between the secondary discharge circuit and the tertiary discharge circuit.

[0057] The third switch is used to control the conduction or disconnection between the third-level discharge circuit and the fourth-level discharge circuit.

[0058] The reference voltage circuit is used to generate the reference voltage required by the first-level discharge circuit, the second-level discharge circuit, the third-level discharge circuit and the fourth-level discharge circuit. In this application, in order to meet the test needs, the first reference voltage output by the reference voltage circuit is set to 3.6V, the second reference voltage is 2.1V, and the third reference voltage is 1.5V.

[0059] The reference voltage circuit can output the first reference voltage, the second reference voltage and the third reference voltage through the solution in the prior art. The present application does not specifically limit the circuit structure of the reference voltage circuit. The reference voltage circuit can output 3.6V, 2.1V, and 1.5V reference voltages. In a possible embodiment, see Figure 2 The first reference voltage is obtained by a low voltage difference voltage regulator (LDO) with an output reference voltage of 3.6V; the second reference voltage is obtained by a low voltage difference voltage regulator (LDO) with an output reference voltage of 2.1V; and the third reference voltage is obtained by a low voltage difference voltage regulator (LDO) with an output reference voltage of 1.5V.

[0060] In the present application, the first reference voltage provides a reference voltage for the primary discharge circuit and the secondary discharge circuit, the second reference voltage provides a reference voltage for the tertiary discharge circuit, and the third reference voltage provides a reference voltage for the quaternary discharge circuit.

[0061] The battery to be discharged in the present application is a single-cell mobile phone lithium battery. The voltage of the single-cell mobile phone lithium battery after being fully charged is 4.4V. The battery step discharge circuit in the present application is suitable for discharging a single-cell battery within 5V.

[0062] The fully charged battery is first discharged through a primary discharge circuit. The primary discharge circuit uses 3.6V as a reference voltage. When the voltage of the battery B1 to be discharged is higher than the first reference voltage 3.6V, the voltage of the battery B1 to be discharged is discharged to the first reference voltage 3.6V. For example, when the voltage of the battery to be discharged is 4.4V, the voltage of the battery to be discharged can be discharged from 4.4V to 3.6V through the primary discharge circuit.

[0063] When the battery voltage needs to be discharged to below the first reference voltage of 3.6V, the discharge can be continued through the secondary discharge circuit. The secondary discharge circuit uses 3.6V as the reference voltage. After the resistor voltage is divided, the reference voltage range is the voltage interval. When the voltage of the battery to be discharged is lower than the first reference voltage of 3.6V and higher than the minimum value of the voltage interval, the voltage of the battery to be discharged can be discharged to the voltage interval. For example, when the first voltage interval is 2.7V to 3.5V, the voltage of the battery to be discharged can be discharged to 2.7V to 3.5V through the secondary discharge circuit.

[0064] When the battery needs to be discharged further, the discharge can be continued through the three-stage discharge circuit, which uses 2.1V as the reference voltage. When the voltage of the battery to be discharged is higher than the second reference voltage 2.1V and lower than the minimum value of the first voltage interval, the voltage of the battery to be discharged is discharged to the second reference voltage 2.1V. For example, when the voltage of the battery to be discharged is 2.5V, the voltage of the battery to be discharged can be discharged from 2.5V to 2.1V through the three-stage discharge circuit.

[0065] When the battery needs to be further discharged, the discharge can be continued through the four-stage discharge circuit, which uses 1.5V as the reference voltage. When the voltage of the battery to be discharged is higher than the third reference voltage of 1.5V and lower than the second reference voltage of 2.1V, the voltage of the battery to be discharged is discharged to the third reference voltage of 1.5V. For example, when the voltage of the battery to be discharged is 1.8V, the voltage of the battery to be discharged can be discharged from 1.8V to 1.5V through the four-stage discharge circuit.

[0066] The first switch, the second switch and the third switch can control the conduction or disconnection between adjacent discharge circuits. By controlling the states of the first switch, the second switch and the third switch, the cascade relationship between the primary discharge circuit, the secondary discharge circuit, the tertiary discharge circuit and the quaternary discharge circuit can be controlled. In practical applications, the first switch, the second switch and the third switch can be set as push switches.

[0067] By controlling the states of the first switch, the second switch, and the third switch, the discharge circuit of the subsequent stage can be disconnected to obtain lithium batteries of different voltages. In one example, when a 3.6V battery is needed, only the first-stage discharge circuit needs to work, at this time, the first switch is turned off; when a 3V battery is needed, the first-stage discharge circuit can discharge the battery voltage to 3.6V, and the second-stage discharge circuit needs to work to continue to discharge the battery voltage to 3V. At this time, the first switch is turned on and the second switch is turned off; when a 2.1V battery is needed, the first-stage discharge circuit can discharge the battery voltage to 3.6V, and the second-stage discharge circuit can continue to discharge the battery voltage to 2.7V, and the third-stage discharge circuit needs to work to continue to discharge the battery voltage to 3V. The first-stage discharge circuit works to continue discharging the battery voltage to 2.1V. At this time, the first switch is turned on, the second switch is turned on, and the third switch is turned off; when a 1.5V battery is needed, the first-stage discharge circuit can discharge the battery voltage to 3.6V, the second-stage discharge circuit can continue to discharge the battery voltage to 2.7V, and the third-stage discharge circuit can continue to discharge the battery voltage to 2.1V. The fourth-stage discharge circuit is also needed to work to continue discharging the battery voltage to 1.5V. At this time, the first switch is turned on, the second switch is turned on, and the third switch is turned on.

[0068] Since the primary discharge circuit, the secondary discharge circuit, the tertiary discharge circuit and the quaternary discharge circuit have different ranges of battery discharge, when the secondary discharge circuit is working, the primary discharge circuit stops working; when the tertiary discharge circuit is working, the primary discharge circuit and the secondary discharge circuit stop working; when the quaternary discharge circuit is working, the primary discharge circuit, the secondary discharge circuit and the tertiary discharge circuit stop working. This will be introduced in conjunction with specific circuits later.

[0069] In an embodiment of the present application, the battery can be discharged to different voltages using a primary discharge circuit, a secondary discharge circuit, a tertiary discharge circuit, and a quaternary discharge circuit. The cascade relationship between the primary discharge circuit, the secondary discharge circuit, the tertiary discharge circuit, and the quaternary discharge circuit can be controlled by controlling the states of the first switch, the second switch, and the third switch, and the fully charged battery can be discharged to different voltages to obtain lithium batteries with different voltages to meet the needs of battery performance testing, thereby saving labor costs.

[0070] In one possible embodiment, see Figure 2 The first-level discharge circuit 200 includes: a first voltage comparator U1, a first voltage regulator P1, and a first variable resistor VR1.

[0071] The non-inverting input terminal of the first voltage comparator U1 is electrically connected to the positive electrode of the battery B1 to be discharged, the first end of the first switch S1, and the input terminal IN of the first voltage regulator P1, respectively. The inverting input terminal of the first voltage comparator U1 is connected to the first reference voltage 3.6V. The output terminal of the first voltage comparator U1 is electrically connected to the enable terminal EN of the first voltage regulator P1 and the secondary discharge circuit 300, respectively.

[0072] An output terminal OUT of the first voltage regulator P1 is electrically connected to a first end of a first variable resistor VR1 , and a second end of the first variable resistor VR1 is grounded.

[0073] The reference voltage of the first-stage discharge circuit is 3.6V. When the voltage of the battery to be discharged is higher than the first reference voltage 3.6V, the output end of the first voltage comparator U1 outputs a high level, enabling the first voltage regulator P1, so that the first voltage regulator P1 works to output a fixed voltage of 3.3V, and discharges with the maximum discharge current through the first variable resistor VR1, discharging the voltage of the battery to be discharged to the first reference voltage 3.6V.

[0074] Since the startup voltage of the mobile phone is 3.6V, the battery discharged to 3.6V can be used to verify the relevant startup test and the startup low voltage stress test, for example, the display status of the display screen when the mobile phone is turned on. If there is no need to continue discharging the battery to be discharged, the first switch S1 can be disconnected. In the embodiment of the present application, the output voltage of the first regulator P1 is 3.3V, and the magnitude of the discharge current is controlled by adjusting the resistance value of the first variable resistor VR1.

[0075] In one possible embodiment, see Figure 2 The secondary discharge circuit 300 includes: a second voltage comparator U2, a second voltage regulator P2, a second variable resistor VR2, a first NOT gate G1, a first AND gate A1, a first resistor R1 and a fifth variable resistor VR5.

[0076] A first end of the fifth variable resistor VR5 is connected to the first reference voltage 3.6V, and a second end of the fifth variable resistor VR5 is electrically connected to the first end of the first resistor R1 and the inverting input end of the second voltage comparator U2 respectively.

[0077] A second end of the first resistor R1 is grounded.

[0078] The non-inverting input terminal of the second voltage comparator U2 is electrically connected to the second terminal of the first switch S1, the first terminal of the second switch S2, and the input terminal IN of the second regulator P2 respectively, and the output terminal of the second voltage comparator U2 is electrically connected to the first input terminal of the first AND gate A1.

[0079] The input end of the first NOT gate G1 is electrically connected to the primary discharge circuit 200, the output end of the first NOT gate G1 is electrically connected to the second input end of the first AND gate A1, and the output end of the first AND gate A1 is electrically connected to the tertiary discharge circuit 400 and the enable end EN of the second regulator P2 respectively.

[0080] The output terminal OUT of the second voltage regulator P2 is electrically connected to the first end of the second variable resistor VR2, and the second end of the second variable resistor VR2 is grounded.

[0081] The secondary discharge circuit is connected to a reference voltage of 3.6, and 3.6V is divided by the first resistor R1 and the fifth variable resistor VR5. The resistance value of the fifth variable resistor VR5 can be adjusted to adjust the reference voltage connected to the inverting input terminal of the second voltage comparator U2. In an example, when the resistance value of the first resistor R1 is 3K ohms, the maximum range of the fifth variable resistor VR5 is 1K ohms, and the reference voltage connected to the inverting input terminal of the second voltage comparator U2 is equal to 3.6*r1 / (r1+vr5), wherein r1 is the resistance value of the first resistor R1, and vr5 is the resistance value of the fifth variable resistor VR5, r1=3K, and the value range of vr5 is (0~1K). It can be calculated that the reference voltage value range connected to the inverting input terminal of the second voltage comparator U2 is 2.7V~3.6V, and the voltage range is 2.7V~3.6V.

[0082] See also Figure 2 When the voltage of the battery to be discharged is discharged to below 3.6V, the first-stage discharge circuit stops working, the output terminal of the first voltage comparator U1 outputs a low level, and after passing through the first NOT gate G1, it is a high level. At the same time, when the voltage of the non-inverting input terminal of the second voltage comparator U2 is greater than the voltage of the inverting input terminal, the output terminal of the first AND gate A1 outputs a high level, enabling the second voltage regulator P2, so that the second voltage regulator P2 starts to work and outputs a fixed voltage of 3.3V, and discharges through the second variable resistor VR2, and discharges the voltage of the battery to be discharged to the voltage range. In the embodiment of the present application, the output voltage of the second voltage regulator P2 is 3.3V, and the magnitude of the discharge current is controlled by adjusting the resistance value of the second variable resistor VR2.

[0083] In a possible embodiment, when the voltage range is 2.7V to 3.6V, the voltage of the battery to be discharged can be discharged to 2.7V to 3.6V. This voltage range includes the battery voltage that needs to be configured by software when the pre-charging stage is changed to the fast charging stage, that is, 3V to 3.4V; it also includes the over-discharge voltage of the battery with a battery protection board, that is, 3V; in addition, it also includes the shutdown voltage of 3.4V. Therefore, the battery discharged through the secondary discharge circuit can provide the voltage battery required for verification of multiple scenarios, for example, verification of the transition from the pre-charging stage to the fast charging stage.

[0084] In one possible embodiment, see Figure 2 The three-stage discharge circuit 400 includes: a third voltage comparator U3, a third voltage regulator P3, a third variable resistor VR3, a second NOT gate G2 and a second AND gate A2.

[0085] The inverting input terminal of the third voltage comparator U3 is connected to the second reference voltage 2.1V, the non-inverting input terminal of the third voltage comparator U3 is electrically connected to the second end of the second switch S2, the first end of the third switch S3, and the input terminal IN of the third regulator P3 respectively, and the output terminal of the third voltage comparator U3 is electrically connected to the first input terminal of the second AND gate A2.

[0086] The input end of the second NOT gate G2 is electrically connected to the secondary discharge circuit 300, the output end of the second NOT gate G2 is electrically connected to the second input end of the second AND gate A2, and the output end of the second AND gate A2 is electrically connected to the four-stage discharge circuit 500 and the enable end EN of the third regulator P3 respectively.

[0087] An output terminal OUT of the third voltage regulator P3 is electrically connected to a first terminal of a third variable resistor VR3 , and a second terminal of the third variable resistor VR3 is grounded.

[0088] The second reference voltage connected to the three-stage discharge circuit is 2.1 V, which can discharge the voltage of the battery to be discharged to 2.1 V. When the battery to be discharged is discharged through the three-stage discharge circuit, the remaining power of the battery to be discharged is usually small, and high current discharge is not required. Therefore, the output voltage of the third regulator P3 is 1.2V.

[0089] In one possible embodiment, see Figure 2 The four-stage discharge circuit 500 includes: a fourth voltage comparator U4, a fourth voltage regulator P4, a fourth variable resistor VR4, a third NOT gate G3 and a third AND gate A3.

[0090] The inverting input terminal of the fourth voltage comparator U4 is connected to the third reference voltage 1.5V, the non-inverting input terminal of the fourth voltage comparator U4 is electrically connected to the second end of the third switch S3 and the input terminal IN of the fourth regulator P4 respectively, and the output terminal of the fourth voltage comparator U4 is electrically connected to the first input terminal of the third AND gate A3.

[0091] The input end of the third NOT gate G3 is electrically connected to the three-stage discharge circuit 400 , the output end of the third NOT gate G3 is electrically connected to the second input end of the third AND gate A3 , and the output end of the third AND gate A3 is electrically connected to the enable end EN of the fourth regulator P4 .

[0092] The output terminal OUT of the fourth voltage regulator P4 is electrically connected to the first end of the fourth variable resistor VR4, and the second end of the fourth variable resistor P4 is grounded.

[0093] The third reference voltage connected to the four-stage discharge circuit is 1.5 V, which can discharge the voltage of the battery to be discharged to 1.5 V. When the battery to be discharged is discharged through the four-stage discharge circuit, the remaining power of the battery to be discharged is usually small, and high current discharge is not required. Therefore, the output voltage of the fourth regulator P4 is 1.2 V.

[0094] In the present application, the third reference voltage connected to the four-stage discharge circuit is 1.5V, that is, when the battery to be discharged is discharged, it can be discharged to 1.5V at the lowest. The minimum discharge voltage is set to 1.5V, and a battery to be discharged with a lower voltage can be obtained. When the battery to be tested does not have a 0V charging function, the battery can be awakened for charging, thereby preventing the battery from being over-discharged and causing irreversible damage to the battery, thereby reducing battery loss.

[0095] In one possible embodiment, see Figure 2 , the first voltage regulator P1 and the second voltage regulator P2 are boost or buck power supply chips. The first voltage regulator P1 and the second voltage regulator P2 are BOB (Boost or Buck) power supply chips. The input voltage range of the BOB power supply chip is 2.2V~5V. When the voltage of the battery to be discharged is greater than and equal to 3.3V, it can output a fixed voltage of 3.3V. Compared with the low voltage difference linear regulator (LDO), the BOB power supply chip has a larger output current. When the primary discharge circuit and the secondary discharge circuit discharge the battery to be discharged, the power of the battery to be discharged is usually high, and a large current discharge is required. Therefore, the first voltage regulator P1 and the second voltage regulator P2 in the primary discharge circuit and the secondary discharge circuit select BOB power supply chips. For the primary discharge circuit, the maximum discharge current of batteries of various specifications can be adapted by adjusting the resistance value of the first variable resistor VR1, so that the battery to be discharged can be discharged at the maximum current, saving discharge time.

[0096] In one possible embodiment, see Figure 2 The resistance value of the second variable resistor VR2 is greater than the resistance value of the first variable resistor VR1, so that the discharge current of the secondary discharge circuit is smaller than the discharge current of the primary discharge circuit.

[0097] When the discharge current of the battery to be discharged increases, the voltage of the battery to be discharged will decrease. At this time, the reduced voltage of the battery to be discharged is not the actual voltage of the battery to be discharged. In order to reduce the virtual low voltage of the battery to be discharged and make the voltage of the battery to be discharged closer to the actual voltage, the resistance value of the second variable resistor VR2 is greater than the resistance value of the first variable resistor VR1. By reducing the discharge current of the secondary discharge circuit, the virtual low voltage of the battery to be discharged is reduced, and the voltage of the battery to be discharged is closer to the actual voltage. In subsequent charging experiments, the charging time is guaranteed to be closer to the actual usage.

[0098] In one possible embodiment, see Figure 2, the third voltage regulator P3 and the fourth voltage regulator P4 are low voltage drop linear regulators. When the battery to be discharged is discharged through the three-stage discharge circuit and the four-stage discharge circuit, the remaining power of the battery to be discharged is usually small, and there is no need to discharge it with a large current. Therefore, the third voltage regulator P3 and the fourth voltage regulator P4 can select a 1.2V low voltage drop linear regulator (LDO), and adapt to the small current discharge of various batteries by adjusting the resistance values ​​of the third variable resistor VR3 and the fourth variable resistor VR4.

[0099] Also, see Figure 2 , the gate circuit composed of the first NOT gate G1 and the first AND gate A1, the gate circuit composed of the second NOT gate G2 and the second AND gate A2, and the gate circuit composed of the third NOT gate G3 and the third AND gate A3, make each level of the discharge circuit work separately step by step. And for each level of the discharge circuit, the discharge current is fixed, the discharge time of each level of the discharge circuit can be estimated, and the time taken to discharge the battery to be discharged to a fixed voltage value can also be calculated. For example, the time taken to discharge the battery to be discharged to 2.1V is equal to the sum of the discharge time of the first discharge circuit, the discharge time of the second discharge circuit, and the discharge time of the third discharge circuit.

[0100] The devices used in the battery step discharge circuit in the embodiment of the present application are all conventional devices and are low-cost.

[0101] An embodiment of the present application further provides an electronic device, including: the above-mentioned battery step discharge circuit.

[0102] In the embodiment of the present application, the electronic device may be a battery discharge detection device, which may include the above-mentioned battery step discharge circuit.

[0103] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery step discharge circuit, characterized in that: The battery step discharge circuit comprises: a reference voltage circuit, a primary discharge circuit, a secondary discharge circuit, a tertiary discharge circuit, a quaternary discharge circuit, a first switch, a second switch, and a third switch; The reference voltage circuit is electrically connected to the primary discharge circuit, the secondary discharge circuit, the tertiary discharge circuit, and the quaternary discharge circuit, respectively; the first switch is electrically connected to the primary discharge circuit and the secondary discharge circuit, respectively; the second switch is electrically connected to the secondary discharge circuit and the tertiary discharge circuit, respectively; the third switch is electrically connected to the tertiary discharge circuit and the quaternary discharge circuit, respectively; The reference voltage circuit is used to output a first reference voltage, a second reference voltage and a third reference voltage, wherein the first reference voltage is higher than the second reference voltage and the third reference voltage, and the second reference voltage is higher than the third reference voltage; The primary discharge circuit is used for discharging the voltage of the battery to be discharged to the first reference voltage when the voltage of the battery to be discharged is higher than the first reference voltage; The secondary discharge circuit is used for discharging the voltage of the battery to be discharged to the voltage interval when the voltage of the battery to be discharged is lower than the first reference voltage and higher than the minimum value of the voltage interval; The three-stage discharge circuit is used for discharging the voltage of the battery to be discharged to the second reference voltage when the voltage of the battery to be discharged is higher than the second reference voltage and lower than the minimum value of the voltage interval; The four-stage discharge circuit is used for discharging the voltage of the battery to be discharged to the third reference voltage when the voltage of the battery to be discharged is higher than the third reference voltage and lower than the second reference voltage; The first switch is used to control the conduction or disconnection between the primary discharge circuit and the secondary discharge circuit; The second switch is used to control the conduction or disconnection between the secondary discharge circuit and the tertiary discharge circuit; The third switch is used to control the conduction or disconnection between the third-level discharge circuit and the fourth-level discharge circuit.

2. The battery step discharge circuit according to claim 1, characterized in that: The primary discharge circuit comprises: a first voltage comparator, a first voltage stabilizer, and a first variable resistor; The non-inverting input terminal of the first voltage comparator is electrically connected to the positive electrode of the battery to be discharged, the first end of the first switch, and the input terminal of the first voltage regulator, respectively; the inverting input terminal of the first voltage comparator is connected to the first reference voltage; and the output terminal of the first voltage comparator is electrically connected to the enable terminal of the first voltage regulator and the secondary discharge circuit, respectively; The output end of the first regulator is electrically connected to the first end of the first variable resistor, and the second end of the first variable resistor is grounded.

3. The battery step discharge circuit according to claim 2, characterized in that: The secondary discharge circuit includes: a second voltage comparator, a second voltage stabilizer, a second variable resistor, a first NOT gate, a first AND gate, a first resistor and a fifth variable resistor; The first end of the fifth variable resistor is connected to the first reference voltage, and the second end of the fifth variable resistor is electrically connected to the first end of the first resistor and the inverting input end of the second voltage comparator respectively; The second end of the first resistor is grounded; The non-inverting input terminal of the second voltage comparator is electrically connected to the second terminal of the first switch, the first terminal of the second switch, and the input terminal of the second regulator respectively, and the output terminal of the second voltage comparator is electrically connected to the first input terminal of the first AND gate; The input end of the first NOT gate is electrically connected to the first-stage discharge circuit, the output end of the first NOT gate is electrically connected to the second input end of the first AND gate, and the output end of the first AND gate is electrically connected to the three-stage discharge circuit and the enable end of the second regulator respectively; The output end of the second regulator is electrically connected to the first end of the second variable resistor, and the second end of the second variable resistor is grounded.

4. The battery step discharge circuit according to claim 1, characterized in that: The three-stage discharge circuit includes: a third voltage comparator, a third voltage stabilizer, a third variable resistor, a second NOT gate and a second AND gate; The inverting input terminal of the third voltage comparator is connected to the second reference voltage, the non-inverting input terminal of the third voltage comparator is electrically connected to the second end of the second switch, the first end of the third switch, and the input terminal of the third regulator respectively, and the output terminal of the third voltage comparator is electrically connected to the first input terminal of the second AND gate; The input end of the second NOT gate is electrically connected to the secondary discharge circuit, the output end of the second NOT gate is electrically connected to the second input end of the second AND gate, and the output end of the second AND gate is electrically connected to the enable end of the fourth discharge circuit and the third regulator respectively; The output end of the third regulator is electrically connected to the first end of the third variable resistor, and the second end of the third variable resistor is grounded.

5. The battery step discharge circuit according to claim 4, characterized in that: The four-stage discharge circuit comprises: a fourth voltage comparator, a fourth voltage stabilizer, a fourth variable resistor, a third NOT gate and a third AND gate; The inverting input terminal of the fourth voltage comparator is connected to the third reference voltage, the non-inverting input terminal of the fourth voltage comparator is electrically connected to the second terminal of the third switch and the input terminal of the fourth voltage regulator respectively, and the output terminal of the fourth voltage comparator is electrically connected to the first input terminal of the third AND gate; The input end of the third NOT gate is electrically connected to the three-stage discharge circuit, the output end of the third NOT gate is electrically connected to the second input end of the third AND gate, and the output end of the third AND gate is electrically connected to the enable end of the fourth regulator; The output end of the fourth regulator is electrically connected to the first end of the fourth variable resistor, and the second end of the fourth variable resistor is grounded.

6. The battery step discharge circuit according to claim 3, characterized in that: The first voltage stabilizer and the second voltage stabilizer are step-up or step-down power supply chips.

7. The battery step discharge circuit according to claim 3, characterized in that: The resistance value of the second variable resistor is greater than the resistance value of the first variable resistor.

8. The battery step discharge circuit according to claim 5, characterized in that: The third regulator and the fourth regulator are low voltage drop linear regulators.

9. The battery step discharge circuit according to claim 1, characterized in that: The voltage range is 2.7V to 3.6V.

10. An electronic device, characterized in that: include: A battery step discharge circuit as described in any one of claims 1 to 9.

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