The LM8801 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell and input voltage rails from 2.3V to 5.5V. It provides up to 600 mA load current over the entire input voltage range. The LM8801 has a mode-control pin that allows the user to select continuous PWM operation over the complete load range or an auto PFM-PWM mode that changes modes automatically depending on the load. During PWM mode, the device operates at a fixed-frequency of 6 MHz (typ.). In Auto PFM-PWM mode, hysteretic PFM extends the battery life through reduction of the quiescent current during light loads and system standby.