The ICs integrate seven high-performance, low-operatingcurrent power supplies along with supervisory and management functions. Regulator outputs include three stepdown DC-DC outputs, three linear regulators, and a seventh always-on output. DC-DC converter outputs power I/O, DRAM, and the CPU core. The I/O supply can be preset to 3.3V or 3.0V, or can be adjusted to other values. The DRAM supply on the MAX1586A and MAX1587A is preset for 1.8V or 2.5V, while the MAX1586B DRAM supply is preset for 3.3V or 2.5V. The DRAM supply on all parts can also be adjusted with external resistors. The CPU core supply is serial programmed for dynamic voltage management. Linear-regulated outputs are provided for SRAM, PLL, and USIM supplies. To minimize sleep-state quiescent current, critical power supplies have bypass "sleep" LDOs that can be activated to minimize battery drain when output current is very low. Other functions include separate on/off control for all DC-DC converters, low-battery and dead-battery detection, a reset and power-OK output, a backupbattery input, and a two-wire serial interface.