Research On The Power Management IC With High Stability

As the rapid development of integrated circuit (IC) industry as well as theincreasing market demands on analog ICs, the power management (PM) IC wasapplied wider and wider. Thus, more and more manufacturers put their efforts into theresearch and development of high performance PM ICs. Among the performances,the work stability is of key importance on PM IC..Based on the investigation in development of PM ICs, the paper focused thetopic on their stability issues. After analyzing several occasions that cause theirinstability, the discussion on the their stability under influence of fluctuant powersupply, temperature and load was given in details. And then the circuitries to improvetheir stability under these fluctuations were proposed to ensure the safe, steady andreliable work of PM ICs, which were successfully applied to the development of somechips such like the VRLA charge IC with high stability.The innovation of proposed VRLA charger IC which was cooperated with anMCU, it could be programmed to fit different requirements requested by differentrechargeable batteries. Four charging modes could be alternately provided accordingto different applications to optimize the battery charging. In this way, the chargingefficiency could be maximized while charge system works safely and steadily. Andthe life-span of the batteries could be prolonged.The structure of the charger IC was composed of power-protection,temperature-protection, over-current and over voltage modules. The IC was designedin 1.5μm 50 V BCD technology. The simulation and test results showed that allcircuitries worked well and high stability was achieved. The IC could work steadilyunder the conditions when the power supply, temperature and load fluctuated.