The Low Power Protection Circuit Design Of Lithium-ion Battery

With the population of portable electronic device, Lithium ion batteries,known as the"heart"of electrical apparatus,have gained much more attention than before. Because they are easily damaged by overcharge,overdischarge and overcurrent, the design for its protection becomes very important. The function of the protector IC required that it can wok with low voltage and very low power; and when it works in difference conditions it has multi-series. Under this precondition ,we finished the paper combining the practical project ,and this work has great advanced and practical values.The paper begins with the introduction of its using means and the basic functions, then its system configuration is designed; and in order to decrease system power the paper puts forward the model of MOS subthreshold region and analyzes its working principle, and explains the deleption MOS working principle. Under this background, the paper designs the main circuit blocks, including reference voltage circuit,overcharge detection circuit,overdischarge detection circuit,overcurrent detection circuit,0V inhibition circuit,charge detection circuit,oscillator circuit and divider circuit.The circuits are fabricated with the UMC 0.6μm CMOS process,and the post simulation under Hspice have shown that the circuit has worked very well and every electrical characteristic meets the specification of the data sheet which proves a successful design.