CN218771379U

CN218771379U - Wireless charging protection circuit for lithium battery

Info

Publication number: CN218771379U
Application number: CN202223227068.2U
Authority: CN
Inventors: 章斌杰; 李辉
Original assignee: Shenzhen Xinjie Silicon Technology Co ltd
Current assignee: Shenzhen Xinjie Silicon Technology Co ltd
Priority date: 2022-12-02
Filing date: 2022-12-02
Publication date: 2023-03-28
Anticipated expiration: 2032-12-02

Abstract

The utility model discloses a wireless protection circuit that fills of lithium cell provides this scheme to the complicated and sudden change of current of structure burn chip scheduling problem among the prior art. The temperature detection device comprises a main control module integrated on a PCB, and a wireless receiving module, an LED indicator light module, a temperature detection module, a lithium battery protection module and an I2C interface module which are respectively connected with the main control module; wherein, the wireless receiving coil L1 of the wireless receiving module is arranged outside the PCB. The method has the advantages that the method does not need software/firmware to carry out programming operation, supports the I2C interface to realize configuration upgrading and parameter debugging, and realizes flexible configuration of protocol and chip parameters; the protection functions of overvoltage clamping protection at the VRECT end of rectification output, input overvoltage protection, output overcurrent protection, over-temperature protection inside and outside the chip, FOD foreign matter protection and the like are realized, and the chip is prevented from being damaged; the circuit is integrated, peripheral components are extremely simple, the size is small, the occupied space is small, the circuit cost is low, the power consumption is low, and the temperature rise of a circuit system is moderate.

Description

Wireless charging protection circuit for lithium battery

Technical Field

The utility model relates to a wireless protection circuit that fills of lithium cell.

Background

At present, most of lithium battery wireless charging protection circuits on the market are of discrete circuit structures and are composed of a voltage reduction DC-DC module, a lithium battery protection IC module, a charging management IC module, a single chip microcomputer master control circuit, an LC resonance receiving circuit and a diode rectifier bridge. The receiving module couples energy from a transmitting end through a secondary coil, and then converts the energy into direct-current voltage through a diode rectifier bridge circuit to supply power for a post-stage circuit, such as a voltage reduction DC-DC module, a single chip microcomputer master control and the like. Therefore, a voltage stabilizing tube is required to be added at the main control power supply end of the single chip microcomputer, and a TVS tube is required to be added at the voltage reduction DC-DC input end for voltage clamping protection; and outputting the stable voltage to the charging management IC module for power supply through the step-down DC-DC module.

The problem is that if the coil of the transmitting terminal and the coil of the receiving terminal are displaced or the power of the transmitting terminal is changed, the energy coupled to the receiving terminal is suddenly changed, so that the output voltage of the diode rectifier bridge circuit is greatly jittered. Although there is a TVS transistor at the input of the buck DC-DC module, the TVS transistor cannot clamp the voltage to a constant level. Therefore, when the output voltage of the diode rectifier bridge circuit is high, the step-down DC-DC module is easily burnt, and the whole circuit cannot work normally. The power supply end in the master control of the single chip microcomputer is provided with the voltage stabilizing tube and the current limiting resistor, and the current flowing through the voltage stabilizing tube and the current limiting resistor is obviously increased, so that the risk of burning out components is increased. On the other hand, the TVS tube and the voltage regulator tube are power consumption devices, and the charging efficiency of the whole system is reduced.

In addition, the wireless charging protection circuit of the lithium battery on the market has more discrete modules, complex peripheral components, large volume, large occupied space, high circuit cost, more and dispersed power switches, high temperature rise of the whole circuit system and easy heating and scalding.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a wireless protection circuit that fills of lithium cell to solve the problem that above-mentioned prior art exists.

The utility model discloses in the wireless protection circuit that fills of lithium cell, include: the temperature detection device comprises a main control module integrated on a PCB, and a wireless receiving module, an LED indicator light module, a temperature detection module, a lithium battery protection module and an I2C interface module which are respectively connected with the main control module; the wireless receiving coil L1 of the wireless receiving module is arranged outside the PCB;

the main control module comprises a main control chip U1, and the main control chip U1 integrates a wireless receiving full-bridge rectification module, a linear voltage reduction module, a charging management module and a wireless/wired change-over switch access.

The COMM1 pin and the COMM2 pin of the main control chip U1 are used for sending ASK signals to the wireless receiving module; the BST1 pin and the BST2 pin are used for boosting the high-side N-MOS of the wireless receiving full-bridge rectification module; the AC1 pin and the AC2 pin are used for receiving energy of the wireless receiving coil L1; the VRECT pin is the output end of the wireless receiving full-bridge rectification module, is connected with the SINK pin in a bridge connection way through a resistor R2 and is used for overvoltage protection; the VOUT pin is used as battery management output, and is externally connected with a lithium battery through the lithium battery protection module; a GPIO0 pin and/or a GPIO1 pin are/is used as input ends of detection or external interruption or internal information test; the SDA pin and the SCL pin are respectively connected with the I2C interface module and are used for configuring and adjusting the communication of the EEPROM in the main control chip U1, and the SDA pin and the SCL pin are also connected with the VDD50 pin through a resistor R4 and a resistor R5 which are connected in parallel; and the VDD50 pin is used as an output decoupling pin of an LDO (low dropout regulator) in the main control chip U1, so that the power supply of an internal circuit is stable.

And a resistor R3 and an LED are connected between the GPIO0 pin and the ground in series.

A resistor R6 and a resistor R7 which are connected in parallel are connected between the GPIO1 pin and the ground; the resistor R6 and the resistor R7 are NTC resistors and are used for temperature detection.

The wireless receiving module comprises a wireless receiving coil L1, a capacitor Cd1 and a plurality of chip selection capacitors connected in parallel; the capacitor Cd1 is bridged between an AC1 pin and an AC2 pin of the main control chip U1; and the wireless receiving coil L1 is connected in series with the plurality of parallel chip selection capacitors and then connected in parallel at two ends of the capacitor Cd 1.

The utility model discloses in lithium cell wireless protection circuit that fills, its advantage lies in, does not need software/firmware to carry out programming operation, supports I2C interface and realizes the configuration upgrading, parameter debugging, realizes the nimble configuration of agreement and chip parameter; the protection functions of overvoltage clamping protection at the VRECT end of rectification output, input overvoltage protection, output overcurrent protection, over-temperature protection inside and outside the chip, FOD foreign matter protection and the like are realized, and the chip is prevented from being damaged; the circuit is integrated, peripheral components are extremely simple, the size is small, the occupied space is small, the circuit cost is low, the power consumption is low, and the temperature rise of a circuit system is moderate.

Drawings

Fig. 1 is a schematic structural diagram of the wireless charging protection circuit of the lithium battery.

Fig. 2 is a schematic structural diagram of the main control module.

Fig. 3 is a schematic structural diagram of the LED indicator light module.

Fig. 4 is a schematic structural diagram of the temperature detection module.

Fig. 5 is a schematic structural diagram of the I2C interface module.

Fig. 6 is a schematic structural view of the lithium battery protection module.

Fig. 7 is a schematic structural diagram of the wireless receiving module.

Detailed Description

As shown in fig. 1 to 7, in the utility model discloses in the wireless protection circuit that fills of lithium cell includes the host system of integration on the PCB board, and respectively with wireless receiving module, LED indicator module, temperature detection module, lithium cell protection module and the I2C interface module that host system connects. Wherein the wireless receiving coil L1 of the wireless receiving module is arranged outside the PCB.

The main control chip U1 wirelessly receives a full-bridge rectification module, a linear voltage reduction module, a charging management module and a wireless/wired change-over switch access, and a circuit module is integrated for processing.

An LC resonance circuit consisting of chip selection capacitors CS 1-CS 4, a capacitor Cd1 and a wireless receiving coil L1 is connected to an AC1 pin and an AC2 pin. The BST1 pin and the BST2 pin are used for boosting a high-side N-MOS of the wireless receiving full-bridge rectification module and are respectively connected with the AC1 pin in a cross-connection mode through a capacitor Cbst1 and the AC2 pin in a cross-connection mode through a capacitor Cbst2. The COMM1 pin and the COMM2 pin are used as ASK communication pins, the COMM2 pin is externally connected with a capacitor Com 1-AC 2 pin, and the COMM1 pin is externally connected with a capacitor Com 2-AC 1 pin; the part of circuit is an ASK communication circuit of a wireless charging receiving end.

The VRECT pin is used as the output end of the wireless receiving full-bridge rectification module, the resistor R2 in cross connection with the SINK pin forms an overvoltage protection circuit, after overvoltage occurs, the SINK pin pulls down current from the VRECT pin to inhibit the voltage of the VRECT pin from rising, and the main control chip U1 is protected from being burnt by high voltage. The VUSB pin is a wired charging input pin port, and wireless/wired charging is switched in the VUSB pin through a change-over switch; VOUT output is used as battery management output, and can be directly connected to a lithium battery to charge the lithium battery. VDD50 pin is used as internal LDO output decoupling pin, and the power supply stability of the internal circuit is guaranteed.

And both the electron R6 and the electron R7 are NTC resistors, form a temperature detection circuit and detect the external temperature of the main control chip U1 or the temperature of a battery pin. The wireless charging system works normally under the condition of normal temperature, and the wireless charging is disconnected when the temperature is abnormal.

The lithium battery protection module consisting of the voltage stabilizing chip U2, the resistor R8 and the capacitor C8 prevents the battery from being damaged due to the abnormality of overdischarge/overcharge/short circuit and the like of the battery.

And P4 is an I2C communication pin interface, and related parameters of the EEPROM in the main control chip U1 are configured and adjusted through an SDA pin and an SCL pin. The GPIO0 pin and the GPIO1 pin are input as the LED light display and the temperature detection function, respectively, in this embodiment, and external interrupt and internal information test may also be multiplexed in other embodiments.

The utility model discloses in the wireless protection circuit accessible I2C that fills of lithium cell sets up the charging voltage 4.2V 4.35V 4.4V of battery pin, the maximum output circuit 500mA of constant current. The output voltage is dynamically rectified, the optimal dynamic switching response and the overload efficiency are obtained, the CC stage rectification output dynamic tracking battery voltage is supported, and the high-efficiency and quick charging is realized. The power supply has the protection functions of rectification output overvoltage clamping protection, input overvoltage protection, output overcurrent protection, on-chip and external overtemperature protection, FOD foreign matter protection and the like, and can also be used for switching between wired charging and wireless charging.

Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes are intended to fall within the scope of the claims.

Claims

1. Lithium cell fills protection circuit wirelessly, its characterized in that includes: the temperature detection device comprises a main control module integrated on a PCB, and a wireless receiving module, an LED indicator light module, a temperature detection module, a lithium battery protection module and an I2C interface module which are respectively connected with the main control module; the wireless receiving coil L1 of the wireless receiving module is arranged outside the PCB;

2. The wireless charging protection circuit for the lithium battery as claimed in claim 1, wherein a COMM1 pin and a COMM2 pin of the main control chip U1 are used for sending ASK signals to the wireless receiving module; the BST1 pin and the BST2 pin are used for boosting the high-side N-MOS of the wireless receiving full-bridge rectification module; the AC1 pin and the AC2 pin are used for receiving energy of the wireless receiving coil L1; the VRECT pin is the output end of the wireless receiving full-bridge rectification module, is connected with the SINK pin in a bridge connection way through a resistor R2 and is used for overvoltage protection; the VOUT pin is used as battery management output, and is externally connected with a lithium battery through the lithium battery protection module; a GPIO0 pin and/or a GPIO1 pin are/is used as input ends of detection or external interruption or internal information test; the SDA pin and the SCL pin are respectively connected with the I2C interface module and are used for configuring and adjusting the communication of the EEPROM in the main control chip U1, and the SDA pin and the SCL pin are also connected with the VDD50 pin through a resistor R4 and a resistor R5 which are connected in parallel; and the VDD50 pin is used as an LDO output decoupling pin in the main control chip U1, so that the power supply of an internal circuit is stable.

3. The wireless lithium battery charging protection circuit of claim 2, wherein a resistor R3 and an LED are connected in series between the GPIO0 pin and ground.

4. The wireless lithium battery charging protection circuit of claim 2, wherein a resistor R6 and a resistor R7 which are connected in parallel are connected between the GPIO1 pin and the ground; the resistor R6 and the resistor R7 are NTC resistors and are used for temperature detection.

5. The wireless charging protection circuit of the lithium battery as claimed in claim 2, wherein the wireless receiving module comprises a wireless receiving coil L1, a capacitor Cd1 and a plurality of chip selection capacitors connected in parallel; the capacitor Cd1 is bridged between an AC1 pin and an AC2 pin of the main control chip U1; and the wireless receiving coil L1 is connected with the plurality of parallel chip selection capacitors in series and then connected to two ends of the capacitor Cd1 in parallel.