Design Of A Low Power Protection IC For The Charging And Discharging Of The Lithium Battery

For its mini bulk, light weight, high power dense, lasting life and safety for environment, the lithium-ion battery has been taking the place of the nickel-cadmium battery and the nickel-hydrogen battery more and more often in today's portable instruments such as mobile phone, notebook computer, PDA, camera and so on. What's more, it's supposed to be the power source of the electric tools, electric bicycles and electric cars in the near future.The lithium-ion battery's native attribute determines that each lithium-ion battery needs a protection IC inside, which can prevent the battery from overcharge, overdischarge, overdischarge current and short during the process of charging and discharging. In this paper, the research and design of a low power protection IC for single lithium-ion battery with full function is demonstrated. According to the functions the IC should have, the structure and functional blocks of the system were determined, then the direct schematic design of some subcircuits had also been conducted, using the"Bottom-to-up"methodology. Then, the whole chip simulation was conducted to examine the matching between the design and the requirements of specification. This paper put emphasis on the whole design of the chip and its realization of low power, especially on the design of some critical blocks, such as reference block, comparator and logic control block.The design was simulated with Hspice based on the UMC 0.6μm process, and the simulation results proved the success of front-ended design.