MOS tube material selection for protection board
Lithium battery is mainly composed of two blocks, the battery cell and protection board PCM (power battery is generally known as the battery management system BMS), the battery cell is equivalent to the heart of the lithium battery, the management system is equivalent to the brain of the lithium battery.
2 series protection board: KND3502A (low start 1.8V)
3-4 series protection board: KIA50N03AD, KIA100N03AD/KND3203B/KIA2803A/KND3204A
7-10 series special MOS for protection board: KND3306B/KNB3306B (68V)
10 -16 series MOS for protection board: KNB3308A/KNB3208A/KIA75NF75KNB3308B/KNB2808A
17 series MOS for protection board: KNB3208A (85V)
17-21 series protection board:KNB2910A/KNP2910A
Lithium battery protection board in daily life will often come into contact with various types of electrical appliances, its most important components are IC and MOS tube, MOS tube on the role of lithium battery protection board is very large.
First of all, first understand the MOS tube on the lithium battery protection mainly which three points:
1, voltage protection
2, current capability
3, on-state resistance
Overcharge protection board: the protection board must have the function of preventing the voltage of the battery core from exceeding the preset value
2, current capability (overcurrent protection current, short circuit protection)
Protection board as a lithium battery cell safety protection equipment, both in the normal operating current scale of the equipment to work reliably, but also in the battery was accidentally short-circuit or overcurrent when the rapid action, so that the cell is protected.
Due to the high operating frequency of communication equipment, data transmission requires a low bit error rate, the rising and falling edge of the pulse string is steep, so the current output capacity of the battery and voltage stability requirements are high, so the protection board MOS tube switch on resistance to small, single-cell protection board is usually in <70mΩ, such as too large will lead to abnormal operation of communication equipment, such as cell phones in the call suddenly disconnected, the phone can not be connected, noise and other phenomena. Noise and other phenomena.
The lower the internal resistance of the protection board, the better, the lower the less heat. The current limit of the protection board is dependent on the resolution of the Kang copper wire sampling resistance, but the continuing current is the resolution of the mos, choose the appropriate mos model is also very important.