The power bus of the battery pack needs to avoid being affected by lithium-ion battery overcurrent and ESD. The control lines (such as SMbus, I2C, etc.) also need to avoid being affected by ESD. The low-voltage (≤5V) ESD protection circuit is as follows:
This solution complies with IEC61000-4-2 air 15KV contact 8KV.
The overcurrent protection of the battery pack uses YINT's SMD PPTC, packaged 0603, 0805, 1206, 1210, 1812, 2018, 2920 and so on. ESD protection can use discrete multilayer varistors or diode arrays.
Regarding the safety of the battery pack, it meets the test methods: UL 1642 UL 2054 IEC 61960 IEC 62133; regarding the ESD anti-static protection diode, it meets IEC 61000-4-2.
PPTC (resettable fuse) needs to be selected carefully to ensure the performance of the overcurrent device. It is important to consider the rated temperature of the battery pack because this temperature will affect the trip point and trip time of the overcurrent protection device.