Design Of A High Performance Protection Chip For The Charging And Discharging Lithium-Ion Battery

With its small size, light weight, long service life, high density to storing power,no memory effect, green environmental protection and other advantages, Lithium-ion battery outstand from the traditional rechargeable batteries and become the primary power of the electronic industry. Determined by the unique nature, Lithium-ion battery must be integrated with a protection chip to monitor the various status of the charging and discharge process in real-time, as well as to protect and control the lithium-ion battery to improve the safety in use and prevent the lithium ion battery characteristic degradation.Studying the basic and demanded protecting function of the chip, A new Application-specific chip has been designed for the high performance charging and discharging Lithium-ion battery. This chip is composed of various circuits, mainly including reference source, sampling, thermal protection, the comparator and the frequency division time-delay control circuits and so on. There are mainly three methods in making the new chip, Using the charge and discharge control pipe MOSFET to improve the integration; the inner thermal protection in the chip as well as the temperature coefficient of the battery to double protect the damage of the chip and the battery when working; then using trimming technology to improve the precision of the whole circuit, When finishing the above, there will be an simulation analysis for the functions.The chip design is based on the 0.5um DPTM BCDMOS technology of CSMC company, while the circuit design has been verified by the Candence simulation platform. The result showed the maximum precision is ± 20mV; the quiescent current is about 3μA and the maximum current of the sleep mode is about 0.1μA. The simulation testing shows that the chip can realize the basic functions, but at the same time, the new chip has the new characters of working in high precision, low powerconsumption, high integration and other high performance advantages, Which can achieve the desired required data.