Switching1-3Cell Li-ion Battery Charge Management Design

With the rapid development of portable electronic products, Consumers areincreasingly high requirements on the products. The advantages of lithium-ion batteriesbecome the preferred battery. Such as: small-volume, high-energy, light quality,long-life, low-cost, non-polluting, etc. However, in order to adequately utilize thecapacity of the battery to extend battery life and improve the safety and reliability of thebattery, you need a complete battery management solution program to strictly controlthe battery charge and discharge mode and to prevent the battery over-voltage,over-discharge, over-temperature, short-circuit as well as over-current and damage thebattery. Therefore, design a functional battery management chip has a certainsignificance and market demands.For lithium battery management chip research, this paper first introduces the powerconverter topology, the operating mode and modulation mode, then state-spaceaveraging method is applied to the power converter, deduce the average switch model ofthe pulse width modulator and the peak current sampling model, using this modeldesign battery management chip in this paper and verify system stability. Analyzing thestability of the converter, elaborate on the relationship between the loop gain with thesystem load regulation and line regulation, thus leads to rapid and stable convertercompensation technology.Based on the overall structure of the system modeling, Design a Buck1-3cellLi-ion battery the PWM charge management chip, According to the performance index,design of each module circuit, including the high-voltage reference circuit, a linearmodulator, the charge pump etc. Finally, the overall simulation of the lithium batterycharge management chip designed in this paper has a perfect system functions, such as:Smart Power Selector system、smart battery detection、cycle by cycle current limit、programmable cell count and the safe and efficient charging mode etc. Describe goodchip performance, it can be widely used in notebook computers、industrial and medicalequipment、handheld terminal and portable equipment etc.