Working principle of battery protection board

Lithium battery protection plate according to the use of IC, voltage and other different circuit and parameters are different, commonly used protection IC has 8261,DW01+,CS213,GEM5018, etc., seiko 8261 series precision is better, of course, the price is more expensive.  DW01+ with MOS tube 8205A (8PIN) DW01+ with MOS tube 8205A (8PIN)  

The normal working process of lithium battery protection plate is as follows:  

When the cell voltage is between 2.5V and 4.3V, the first pin and the third pin of DW01 both output high level (equal to the supply voltage), and the voltage of the second pin is 0V.  At this point, the voltage of pin 1 and pin 3 of DW01 will be added to pin 5 and pin 4 of 8205A respectively. The two electronic switches in 8205A are in the on-state because their G pole is connected to the voltage from DW01, that is, the two electronic switches are in the open state.  At this time, the negative electrode of the cell and the p-end of the protection plate are directly connected, and the protection plate has voltage output.