Unique control schemes extend battery life in portable equipment

New power conversion chipsets allow the newest generation of portable equipment to achieve smaller size, lower weight, and longer battery life, while still maintaining low cost. These new ICs provide high efficiency over a wide range of loads, have low-power standby modes and load management capabilities, and require only a small amount of board area. This paper describes some of these new ICs and their applications circuits. It presents a dual 3.3 V/5 V-output supply that is efficient over three decades of load currents. It discusses an integrated high-efficiency, cold cathode fluorescent tube (CCFT) backlight and LCD backplane power source. Also presented are intelligent battery chargers, embedded control for PCMCIA card slots, and minimum-power EIA232 transceivers with receivers active in shutdown.