The MAX1615/MAX1616 are micropower, SOT23-5 linear regulators that supply always-on, keep-alive power to CMOS RAM and microcontrollers (µCs) in systems with high-voltage batteries. Key features include wide input voltage range, low dropout voltage, and low quiescent supply current. Despite a miserly 8µA (max) no-load supply current, the MAX1615/MAX1616 have excellent line-transient response and AC power-supply rejection ratio. They provide a clean, fixed 5V or 3.3V output (MAX1615) or an adjustable 1.24V to 28V output (MAX1616), even when subjected to fast supply-voltage changes that occur during the switchover from battery to AC adapter input power. The space-saving SOT23-5 package has excellent thermal characteristics and tolerates up to 571mW of power dissipation. Fault protection is provided by internal foldback current limiting and thermal-shutdown circuitry. The MAX1615/MAX1616 are now available in lead-free packages. Applications * Battery-Powered Systems * CMOS/RTC Backup Power * Microcontroller Power * Notebook Computers * PDAs and Handy-Terminals * Smart Battery Packs/Chargers * 4V to 28V Input Range * 8µA (max) Quiescent Supply Current * <1µA Shutdown Supply Current * 3.3V or 5V, Pin-Selectable Output (MAX1615) Adjustable 1.24V to 28V Output (MAX1616) * 30mA Output Current * ±2% Initial Output Accuracy * Thermal-Overload Protection * 5-Pin SOT23 Package * Low Cost