The Design Of Power Management System For Laptop

Power is one of the important parts for all electronic equipments and devices. The power's improvement will directly lead to the performance improvement of the whole system, especially for laptop computer. Compared with desktop, the most outstanding advantage of laptop is the transportability and battery is the vital device to accomplish this function. With development of the LST, laptop becoming more and lighter, thinner, smaller and higher density, the improvement speed for power energy density cannot catch up with laptop's development speed for miniaturization and high-integration. This contradiction requires keeping improving the power management to make up the deficiency of the growing power consumptions following the high-integration, for the sake of reducing power consumptions and extending the usage time.Based on the whole set of design, this paper also discusses the improving method of power management and increasing the product services life by reducing M/B temperature when using adapter. The design also can help have longer usage time when using battery and can help have better performance when using adapter to provide power. This paper optimizes the whole system which is based on Micro process H8, then based on the request from chipset for power management, it designs several DC/DC transform circuit, power switch circuit between battery and adapter and battery charge function circuit to power for the whole chipset and external device.The whole comprehensive tests which include power output accuracy, line regulation, load characteristics, ripple and noise and so on show that the whole system not only have stable run, better performance but also have the advantage of small capacity, low power loss and more efficiency.