The MAX886/MAX888 power-management ICs are complete power systems for wireless and satellite handsets. The devices operate from 3 to 6-cell NiCd/NiMH batteries or from 1 or 2-cell Li-Ion batteries. They incorporate a high-efficiency, step-down DC-DC converter, a regulated 5V charge pump, and four linear regulators. The regulators supply power to the SIM, LCD, BB, DSP, and RF sections of a cellular telephone handset. The step-down converter and linear regulator outputs are adjustable by internal 4-bit DACs, programmable through the I2CTMcompatible serial interface. A pushbutton on/off scheme activates a 5A low-power shutdown mode. The devices also feature a low-battery detector output and an internal start-up timer.