The LM3674 step-down DC-DC converter is optimized for powering low-voltage circuits from a single Li-Ion cell battery and input voltage rails from 2.7 V to 5.5 V. It provides up to 600-mA load current over the entire input voltage range. There are several fixed output voltages and adjustable output voltage versions. The device offers superior features and performance for mobile phones and similar portable systems. During the Pulse Width Modulation (PWM) mode, the device operates at a fixed-frequency of 2 MHz (typical). Internal synchronous rectification provides high efficiency during the PWM mode operation. In shutdown mode, the device turns off and reduces battery consumption to 0.01 µA (typical). The LM3674 is available in a 5-pin SOT-23 package. A high switching frequency of 2 MHz (typical) allows use of only three tiny external surface-mount components, an inductor and two ceramic capacitors.