| With the development of mini bulk, light weight, high performance and the popularization for portable electronic device, the rechargeable battery as its power market is rapidly expanding, and the many advantages of lithium-ion battery make itself as the mainstream product in the market of secondary battery. But on the other hand, because of the unique nature of lithium-ion batteries, a lithium battery protect-chip is embedded into each battery pack to prevent the abnormal phenomenon of lower battery discharge efficiency, shorten battery life and security which are caused by lithium-ion battery's over-charging, over-discharging, over-current and short-circuit, etc. Combined with the research of the practical project, this paper discusses the research and design of high-precision single cell lithium-ion protection circuit and this work has great practical and theoretical value.This thesis begins with application ways and basic functions of lithium-ion battery protection circuit, then analyses and designs the system architecture and function modules, and on this basis, designs a high-precision single-mode lithium-ion battery protection circuit through the wide use of customized application for benchmark circuit and testing technology. The main circuit module is composed of benchmark circuit, sampling circuit, overcharge detection circuit, excessive discharge detection circuit, over-current detection circuit, short-circuit detection circuit and charger detection circuit. Finally, do the simulation test to the designed circuit simulation, and thereby achieve the objective of the design. The study has focused on the implementation of a variety of lithium battery protection function and the requirement for testing high precision of the circuit voltage.The design was simulated with the Spectre based on the CSMC 0.6μm process, and the simulation results manifest that the protection chip and system can finish a variety of protection functions, as well as low quiescent current, high detection accuracy, good safety and reliability. |
