The working principle and important components of lithium battery protection chip

The working principle and important components of lithium battery protection chip. The principle of the lithium battery protection board is very simple, with few electronic components. Lithium battery protection board is mainly composed of maintenance IC and MOS tube to protect the safety of lithium battery. Lithium batteries have the advantages of large discharge current, low internal resistance, long life, and no memory effect, and have been widely used. The working principle of lithium battery protection chip Lithium battery will be used in the design of lithium battery protection board or corresponding BMS, even through various communication protocols, but it is very important to protect lithium battery, the working principle of protection chip, you must know that only through To understand the basic working principle of the protection chip, in order to better design the lithium battery pack, it can even help the quality analysis of abnormal cells or circuits together. Lithium battery pack. JPGIC: It is the core of the protection chip. The battery voltage is sampled first, and then various commands are issued through judgment. MOS tube: It is mainly used as a switch. 2. The protection chip works normally: the MOS tube on the protection chip can be turned off at the beginning. After the battery is connected to the protection chip, the MOS tube must be triggered first. 3. Protection chip overcharge protection: P+ and P- are connected to a power supply that is higher than the battery voltage, the positive answer of the power supply is B+B-, the power of the cathode, when the power supply is connected, start charging, as shown in the current from the positive In the direction I1, the current flowing through the battery, D1, the molybdenum disulfide power cathode (at this time MOS1D1 is short-circuited), the capacitance value of the battery voltage of the integrated circuit sample, when the battery voltage is 4.25v, the integrated circuit issues an instruction to make Pin Co. The low level, currently from the front, flowing through the battery, D1, reaches the molybdenum disulfide because the molybdenum disulfide grid and the company and the low level, when the molybdenum disulfide is closed, the entire circuit is closed and the circuit plays a protective role. 4. Protection chip over-discharge protection: After connecting a suitable load on P+ and P-, the lithium battery starts to discharge in the direction of I2. The current flows from the positive pole of the battery through the load D2 and MOS1 to the negative pole of the battery (when MOS2 is short-circuited by D2). When the battery is discharged to 2.5v, IC samples and instructs MOS1 to stop, the circuit is disconnected, and the battery is protected. 5. Over-current protection: After connecting a suitable load to P+ and P-, the battery starts to discharge in the direction of current such as I2. The current flows from the positive pole of the battery through the load D2 and MOS1 to the negative pole of the battery (when MOS2 is short-circuited by D2). When the load drops suddenly, the IC samples the voltage appearing when the current is suddenly increased through the VM pin, then samples the IC and orders MOS1 to disconnect, disconnect the circuit, and protect the battery. 6. Short circuit protection: After P+ and P- load, the lithium battery starts to discharge in the direction of I2. The current flows from the positive pole of the battery through the load D2 and MOS1 to the negative pole of the battery (when MOS2 is short-circuited by D2). The IC samples the current through the VM pin to suddenly increase the voltage that appears. At this time, the IC samples and issues an instruction to turn off MOS1, disconnect the loop, and protect the battery. Lithium battery is an important component of the protection chip. The protection function of the lithium battery pack is usually completed by the protection circuit board and PTC. The protection board is composed of electronic components, which can accurately monitor the battery voltage and the current of the charging and discharging circuit at -40℃~+85℃, and control the on and off of the current circuit in time. The important function of PTC is to protect the battery from burning, explosion and other vicious accidents in high temperature environment. 1. Overload protection PTC (Automatic Train Control System) 1. The PTC component supports the overcurrent protection of the battery pack. The resistance of the device will increase linearly with temperature. 2. PTC is often called an overcurrent protector in lithium battery electronic circuits, and the cost is relatively high. PTC (polysaccharide polymer switch), also known as overcurrent protector, is mainly used for short circuit and overload protection of low-power electronic devices. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.