A battery overdischarge protection circuit

Abstract

The utility model discloses a battery overdischarge protection circuit, its under voltage circuit adopts chip U3 and MOS pipe Q3 to read and switch on the voltage of battery, when voltage is lower than the preset value, cut off to the circuit, realize timely, effective prevention battery overdischarge, prevent the battery from entering the power shortage state, and low pressure alarm module can send light prompt when the voltage of battery reduces, safer.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery over-discharge protection circuit. Background Technology

[0002] If the circuit consumes too much current when it is in a static state, the battery is prone to entering a depleted state, which will accelerate the degradation of battery capacity; the output power of the battery will decrease, affecting the normal use of the device; and the battery efficiency will also be reduced, affecting the battery life.

[0003] Currently, power management modules are often set up to monitor parameters such as voltage and current in order to control and manage the battery, but it is difficult to effectively prevent the battery from entering a state of depletion. Utility Model Content

[0004] The purpose of this utility model is to provide a battery over-discharge protection circuit. Its undervoltage circuit uses chip U3 and MOSFET Q3 to read and conduct the battery voltage, so as to timely and effectively prevent the battery from over-discharge and prevent the battery from entering a low-charge state. In addition, the low-voltage alarm module emits light prompts when the battery voltage drops, which is safer.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A battery over-discharge protection circuit includes an undervoltage protection module and a low-voltage alarm module;

[0007] The undervoltage protection module includes switch J4, chip U3, and MOSFET Q3;

[0008] Pin 1 of switch J4 is connected to port VBAT, and port VBAT is connected to battery (6);

[0009] Pin 2 of switch J4 is connected to resistors R10 and R13, and then to pin 3 of chip U3.

[0010] Pin 2 of chip U3 is connected to the parallel connection of resistors R10 and R13;

[0011] Pin 1 of chip U3 is connected to resistor R11 and then to pin 3 of MOSFET Q3;

[0012] Pin 1 of MOSFET Q3 is connected to pin 2 of switch J4;

[0013] Pin 2 of MOSFET Q3 is connected to port VBAT-OUT;

[0014] A resistor R12 is provided between pin 1 and pin 3 of MOSFET Q3;

[0015] The low-voltage alarm module includes transistors Q1 and Q2;

[0016] Pin 1 of transistor Q1 is connected to resistor R7 and then to port VBAT.

[0017] A resistor R9 is provided between pin 1 and pin 2 of transistor Q1;

[0018] Pin 3 of transistor Q1 is connected to resistor R6 and then to port VBAT.

[0019] Pin 1 of transistor Q2 is connected to pin 3 of transistor Q1;

[0020] Connect pin 3 of transistor Q2 to resistor R8, then connect to port LOW. Connect port LOW to an LED.

[0021] In some implementations, the undervoltage protection module also includes capacitors C12 and C11;

[0022] Capacitor C12 is connected between pins 2 and 3 of chip U3;

[0023] One end of capacitor C11 is connected to pin 2 of MOSFET Q3, and the other end of capacitor C11 is grounded. Pin 3 of chip U3 is grounded.

[0024] In some implementations, a boost module and a wireless charging transmitter module are also included;

[0025] A boost module is used to increase the voltage of a circuit;

[0026] The wireless charging transmitter module is connected to the output terminal of the boost module;

[0027] The wireless charging transmitter module includes a transmitter coil L1.

[0028] In some implementations, the boost module includes a chip U4 and an inductor L2;

[0029] Pin 1 of chip U4 is connected to port VBAT-OUT;

[0030] Pin 2 of chip U4 is connected to inductor L2;

[0031] Pin 5 of chip U4 is connected to port VCC;

[0032] Among them, pin 1 of chip U4 is connected to capacitors C4 and C9 in parallel;

[0033] The end of inductor L2 furthest from pin 2 of chip U4 is connected to capacitors C4 and C9 in parallel.

[0034] Pin 5 of chip U4 is connected to capacitors C10 and C5 in parallel.

[0035] In some implementations, the wireless charging transmitter module includes a chip U2;

[0036] Pin 1 of chip U2 is connected to port VCC and port VBUS;

[0037] One end of the transmitting coil L1 is connected to pin 1 of the chip U2, and the other end of the transmitting coil L1 is connected to pin 7 of the chip U2; and the transmitting coil L1 is connected in parallel with the capacitor C7.

[0038] In some implementations, the wireless charging transmitter module also includes a capacitor C6, a resistor R1, and a resistor R2;

[0039] One end of capacitor C6 is connected to pin 1 of chip U2, and the other end of capacitor C6 is connected to pin 6 of chip U2.

[0040] One end of resistor R1 is connected to pin 8 of chip U2, and the other end of resistor R1 is connected to pin 2 of chip U2; capacitor C6 is placed close to resistor R1.

[0041] One end of resistor R2 is connected to pin 8 of chip U2, and the other end of resistor R2 is connected to pin 5 of chip U2. The other end of resistor R2 is connected to capacitor C8 and then grounded.

[0042] In some implementations, a charging management module is also included;

[0043] The charging management module includes chip U1;

[0044] Pin 1 of chip U1 is connected to port VBUS;

[0045] Pin 1 of chip U1 is connected to capacitor C14 and then grounded; pin 2 of chip U1 is connected to capacitor C15 and then grounded.

[0046] Pin 10 of chip U1 is connected to port VBAT; and pin 10 of chip U1 is connected to capacitor C16 and then grounded.

[0047] In some implementations, pin 15 of chip U1 is connected to capacitor C13 and inductor L3, and then connected to port VBAT.

[0048] Pins 13 and 14 of chip U1 are both connected to inductor L3;

[0049] It also includes socket J1, which is connected to the battery;

[0050] Pin 2 of socket J1 is connected to port VBAT, and pin 2 of socket J1 is connected to capacitor C1, capacitor C2 and diode D1. Capacitors C1, C2 and diode D1 are connected in parallel.

[0051] The beneficial effects of this utility model are: its undervoltage circuit uses chip U3 and MOSFET Q3 to read and conduct the battery voltage, so as to timely and effectively prevent the battery from being over-discharged and prevent the battery from entering a state of low charge.

[0052] Furthermore, the low-voltage alarm module emits a light warning when the battery voltage drops, making it safer. Attached Figure Description

[0053] Figure 1 This is a structural diagram of a battery over-discharge protection circuit according to the present invention;

[0054] Figure 2 This is a circuit diagram of the undervoltage protection module of this utility model;

[0055] Figure 3 This is a circuit diagram of the low-voltage alarm module of this utility model;

[0056] Figure 4 This is a circuit diagram of the boost module of this utility model;

[0057] Figure 5 This is a circuit diagram of the wireless charging transmitter module of this utility model;

[0058] Figure 6 This is a circuit diagram of the charging management module of this utility model;

[0059] The module consists of: 1-undervoltage protection module; 2-low voltage alarm module; 3-boost module; 4-wireless charging transmitter module; 5-charging management module; and 6-battery. Detailed Implementation

[0060] The present invention will now be described in further detail with reference to the accompanying drawings.

[0061] refer to Figures 1 to 3 A battery over-discharge protection circuit includes an undervoltage protection module 1 and a low-voltage alarm module 2;

[0062] Undervoltage protection module 1 includes switch J4, chip U3 and MOSFET Q3;

[0063] Pin 1 of switch J4 is connected to port VBAT, and port VBAT is connected to battery 6. That is, undervoltage protection module 1 is connected to battery 6 through switch J4.

[0064] Pin 2 of switch J4 is connected to resistors R10 and R13, and then to pin 3 of chip U3.

[0065] Pin 2 of chip U3 is connected to the parallel connection of resistors R10 and R13; resistors R10 and R13 divide the voltage of the circuit.

[0066] Pin 1 of chip U3 is connected to resistor R11 and then to pin 3 of MOSFET Q3;

[0067] Pin 1 of MOSFET Q3 is connected to pin 2 of switch J4;

[0068] Pin 2 of MOSFET Q3 is connected to port VBAT-OUT, which is the output terminal;

[0069] A resistor R12 is provided between pin 1 and pin 3 of MOSFET Q3;

[0070] Chip U3 is used to read voltage; the model number of chip U3 is ATL431AQDBZR; the model number of MOSFET Q3 is A03401.

[0071] When the voltage is higher than or equal to the preset value, MOSFET Q3 is turned on, and the VBAT-OUT port outputs voltage; when the voltage is lower than the preset value, MOSFET Q3 is turned off, and the VBAT-OUT port does not output voltage.

[0072] Specifically, battery 6 is a lithium battery, and its operating voltage is about 3.7V, that is, the VBAT port is about 3.7V, and the default value is 3.7V.

[0073] When the voltage of battery 6 is greater than or equal to 3.7V, MOSFET Q3 is turned on, and the VBAT-OUT port outputs voltage.

[0074] When the voltage of battery 6 is lower than 3.7V, that is, when the voltage at port VBAT is lower than 3.7V, the gate voltage of MOSFET Q3 is pulled high by resistor R12, thus cutting off the output voltage at port VBAT-OUT; thereby preventing over-discharge of battery 6, protecting battery 6, and protecting the back-end circuits or devices connected to port VBAT-OUT.

[0075] Furthermore, the undervoltage protection module 1 also includes capacitors C12 and C11;

[0076] Capacitor C12 is connected between pins 2 and 3 of chip U3. Capacitor C12 is used for filtering to reduce interference.

[0077] One end of capacitor C11 is connected to pin 2 of MOSFET Q3, and the other end of capacitor C11 is grounded. Pin 3 of chip U3 is also grounded. Capacitor C11 is used for filtering to reduce interference.

[0078] refer to Figure 3 The low-voltage alarm module 2 includes transistors Q1 and Q2;

[0079] Pin 1 of transistor Q1 is connected to resistor R7 and then to port VBAT.

[0080] A resistor R9 is provided between pin 1 and pin 2 of transistor Q1;

[0081] Pin 3 of transistor Q1 is connected to resistor R6 and then to port VBAT.

[0082] Pin 1 of transistor Q2 is connected to pin 3 of transistor Q1;

[0083] Connect pin 3 of transistor Q2 to resistor R8, then connect to port LOW. Connect port LOW to an LED. Resistor R8 is a current-limiting resistor.

[0084] Both pin 2 of transistor Q1 and pin 2 of transistor Q2 are grounded.

[0085] Therefore, R7 and R9 divide the voltage. When the voltage of battery 6 is higher than or equal to the set threshold (e.g., threshold 3.7V), transistor Q1 is turned on and transistor Q2 is turned off. At this time, the LOW port outputs a high level and the LED is off. Conversely, when the voltage of battery 6 is lower than the set threshold (e.g., threshold 3.7V), resistor R6 pulls up the voltage of transistor Q1, transistor Q1 is turned off, and the LOW port outputs a low level and the LED is on.

[0086] refer to Figure 1 It also includes a boost module 3 and a wireless charging transmitter module 4;

[0087] Boost module 3 is used to increase the voltage of the circuit;

[0088] The wireless charging transmitter module 4 is connected to the output terminal of the boost module 3;

[0089] The wireless charging transmitter module 4 includes a transmitter coil L1.

[0090] For example, the boost module 3 boosts the circuit voltage to about 5V, and the wireless charging transmitter module 4 operates at 5V, transmitting electrical energy through the transmitting coil L1 to achieve the wireless charging function, such as wirelessly charging other devices.

[0091] refer to Figure 4 The boost module 3 includes chip U4 and inductor L2; the model number of chip U4 is TPS61299QDRLRQ1.

[0092] Pin 1 of chip U4 is connected to port VBAT-OUT;

[0093] Pin 2 of chip U4 is connected to inductor L2;

[0094] Pin 5 of chip U4 is connected to port VCC;

[0095] Among them, pin 1 of chip U4 is connected to capacitors C4 and C9 in parallel;

[0096] The end of inductor L2 furthest from pin 2 of chip U4 is connected to capacitors C4 and C9 in parallel.

[0097] Pin 5 of chip U4 is connected to capacitors C10 and C5 in parallel.

[0098] Therefore, capacitors C4 and C9 filter the voltage at the input terminal (port VBAT-OUT); capacitors C10 and C5 filter the voltage at the output terminal (port VCC); when the MOSFET switch inside chip U4 is turned on, inductor L2 absorbs energy from the input terminal (port VBAT) and stores it in the form of a magnetic field; when the MOSFET switch is turned off, inductor L2 releases the stored energy, which is then superimposed on the voltage at the input terminal and transferred to the output terminal (port VCC), thereby achieving voltage boost.

[0099] refer to Figure 5 The wireless charging transmitter module 4 includes chip U2; the model number of chip U2 is XKT-520.

[0100] Pin 1 of chip U2 is connected to port VCC and port VBUS; both port VCC and port VBUS can provide a voltage of about 5V. Port VCC is connected to diode D4 and then to pin 1 of chip U2, and port VBUS is connected to diode D2 and then to pin 1 of chip U2, enabling the two ports to provide a 5V voltage independently or simultaneously; both diodes D4 and D2 are used for rectification.

[0101] One end of the transmitting coil L1 is connected to pin 1 of chip U2, and the other end of the transmitting coil L1 is connected to pin 7 of chip U2; and the transmitting coil L1 is connected in parallel with capacitor C7, which is used for filtering.

[0102] The wireless charging transmitter module 4 also includes capacitor C6, resistor R1 and resistor R2;

[0103] One end of capacitor C6 is connected to pin 1 of chip U2, and the other end of capacitor C6 is connected to pin 6 of chip U2; capacitor C6 is used for filtering.

[0104] One end of resistor R1 is connected to pin 8 of chip U2, and the other end of resistor R1 is connected to pin 2 of chip U2. Resistor R1 is used to convert the current signal into a voltage signal for the switching of the working state. Capacitor C6 is placed close to resistor R1 to reduce circuit interference.

[0105] One end of resistor R2 is connected to pin 8 of chip U2, and the other end of resistor R2 is connected to pin 5 of chip U2. The other end of resistor R2 is connected to capacitor C8 and then grounded. R2 and capacitor C8 filter the sampled voltage signal.

[0106] refer to Figure 6 It also includes a charging management module 5; the charging management module 5 is used for charging the battery 6;

[0107] The charging management module 5 includes chip U1; the model of chip U1 is BQ25308RTER.

[0108] Pin 1 of chip U1 is connected to port VBUS; port VBUS is connected to the output of the adapter to provide a 5V charging voltage.

[0109] Pin 1 of chip U1 is connected to capacitor C14 and then grounded, and pin 2 of chip U1 is connected to capacitor C15 and then grounded; both capacitors C14 and C15 are used for filtering.

[0110] Pin 10 of chip U1 is connected to port VBAT; port VBAT is connected to battery 6, thereby charging battery 6; and pin 10 of chip U1 is connected to capacitor C16 and then grounded, with capacitor C16 used for filtering.

[0111] Therefore, the adapter's 5V voltage is input to chip U1, and then chip U1 outputs 3.7V to charge battery 6. Chip U1 has built-in functions such as battery short-circuit detection and battery overcharge protection.

[0112] Furthermore, pin 15 of chip U1 is connected to capacitor C13 and inductor L3, and then connected to port VBAT.

[0113] Pins 13 and 14 of chip U1 are both connected to inductor L3;

[0114] It also includes socket J1, which is connected to battery 6;

[0115] Pin 2 of socket J1 is connected to port VBAT, and capacitors C1 and C2, along with diode D1, are connected to pin 2 of socket J1 in parallel. Therefore, capacitors C1 and C2 are used for filtering, and diode D1 provides electrostatic discharge protection.

[0116] The above description only discloses some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A battery over-discharge protection circuit, characterized in that, It includes an undervoltage protection module (1) and a low-voltage alarm module (2); The undervoltage protection module (1) includes a switch J4, a chip U3 and a MOSFET Q3; Pin 1 of switch J4 is connected to port VBAT, and port VBAT is connected to battery (6); Pin 2 of switch J4 is connected to resistors R10 and R13, and then to pin 3 of chip U3. Pin 2 of the chip U3 is connected to the parallel connection of resistors R10 and R13; Pin 1 of chip U3 is connected to resistor R11 and then to pin 3 of MOSFET Q3; Pin 1 of the MOSFET Q3 is connected to pin 2 of the switch J4; Pin 2 of the MOS transistor Q3 is connected to the VBAT-OUT port; A resistor R12 is provided between pin 1 and pin 3 of the MOS transistor Q3; The low-voltage alarm module (2) includes transistors Q1 and Q2; The transistor Q1 is connected to resistor R7 and then to port VBAT; A resistor R9 is provided between pin 1 and pin 2 of the transistor Q1; The transistor Q1 is connected to resistor R6 at pin 3 and then to port VBAT. Pin 1 of transistor Q2 is connected to pin 3 of transistor Q1; Pin 3 of transistor Q2 is connected to resistor R8 and then to port LOW. Port LOW is connected to an LED.

2. The battery over-discharge protection circuit according to claim 1, characterized in that, The undervoltage protection module (1) also includes capacitors C12 and C11; The capacitor C12 is connected between pins 2 and 3 of chip U3; One end of the capacitor C11 is connected to pin 2 of the MOSFET Q3, and the other end of the capacitor C11 is grounded. Pin 3 of the chip U3 is grounded.

3. The battery over-discharge protection circuit according to claim 1, characterized in that, It also includes a boost module (3) and a wireless charging transmitter module (4); The boost module (3) is used to increase the voltage of the circuit; The wireless charging transmitter module (4) is connected to the output terminal of the boost module (3); The wireless charging transmitter module (4) includes a transmitter coil L1.

4. The battery over-discharge protection circuit according to claim 3, characterized in that, The boost module (3) includes a chip U4 and an inductor L2; Pin 1 of the chip U4 is connected to port VBAT-OUT; Pin 2 of the chip U4 is connected to inductor L2; Pin 5 of the chip U4 is connected to the VCC port; Among them, pin 1 of chip U4 is connected to capacitors C4 and C9 in parallel; The end of the inductor L2 away from pin 2 of the chip U4 is connected to capacitors C4 and C9 in parallel. Pin 5 of the chip U4 is connected to capacitors C10 and C5 in parallel.

5. The battery over-discharge protection circuit according to claim 3, characterized in that, The wireless charging transmitter module (4) includes a chip U2; Pin 1 of the chip U2 is connected to port VCC and port VBUS; One end of the transmitting coil L1 is connected to pin 1 of the chip U2, and the other end of the transmitting coil L1 is connected to pin 7 of the chip U2; and the transmitting coil L1 is connected in parallel with the capacitor C7.

6. The battery over-discharge protection circuit according to claim 5, characterized in that, The wireless charging transmitter module (4) also includes a capacitor C6, a resistor R1 and a resistor R2; One end of the capacitor C6 is connected to pin 1 of the chip U2, and the other end of the capacitor C6 is connected to pin 6 of the chip U2. One end of the resistor R1 is connected to pin 8 of the chip U2, and the other end of the resistor R1 is connected to pin 8 of the chip U2; wherein the capacitor C6 is positioned close to the resistor R1; One end of the resistor R2 is connected to pin 8 of the chip U2, and the other end of the resistor R2 is connected to pin 5 of the chip U2. The other end of the resistor R2 is connected to capacitor C8 and then grounded.

7. A battery over-discharge protection circuit according to any one of claims 1-6, characterized in that, It also includes a charging management module (5); The charging management module (5) includes a chip U1; Pin 1 of the chip U1 is connected to port VBUS; Pin 1 of chip U1 is connected to capacitor C14 and then grounded; pin 2 of chip U1 is connected to capacitor C15 and then grounded. Pin 10 of the chip U1 is connected to port VBAT; and pin 10 of the chip U1 is connected to capacitor C16 and then grounded.

8. The battery over-discharge protection circuit according to claim 7, characterized in that, Pin 15 of chip U1 is connected to capacitor C13 and inductor L3, and then connected to port VBAT. Pins 13 and 14 of the chip U1 are both connected to inductor L3; It also includes a socket J1, which is connected to the battery (6); Pin 2 of socket J1 is connected to port VBAT, and pin 2 of socket J1 is connected to capacitor C1, capacitor C2 and diode D1, which are connected in parallel.

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