Achieving typical efficiencies greater than 95%, this miniature step-down DC-DC converter helps lengthen the battery lifetime of smartphones and other low-voltage portable products. Diodes' AP3403 is a synchronous PWM converter that drives a load at up to 600 mA, maintaining high efficiency through a configuration of external resistor, capacitor, and inductor components.

To support mini Li-Ion battery operation, the input voltage range is low at 2.7 V to 5 V, with no-load current being only 34 μA. The buck converter ensures excellent line and load regulation and employs current mode control to deliver the fastest possible transient response and cycle-by-cycle current limit.

By operating at a ripple-reducing fixed 2.0 MHz, the AP3403 is able to help reduce the cost and size of external circuit components, while its ultra-small, thermally-efficient U-DFN1616 package further aids a reduction in overall circuit footprint.

The converters output voltage range of 0.7 V to 5.5 V makes it easily configurable to application requirements. System integrity is maintained by a comprehensive array of built-in features that include under-voltage lockout, over-temperature protection, hiccup-mode short-circuit protection, and soft-start functionality.