Diodes Inc. – The 1.5A and 2A AP65101 : Light-load algorithm improves efficiency of DC-DC buck converters


AP65x01: valuable cost and board-space savings

Two new synchronous DC-DC buck converters introduced by Diodes Incorporated offer highly efficient operation at both full and light loads.

The 1.5A AP65101 and 2A AP65201 achieve efficiency of up to 97% at their maximum continuous current. They benefit from a low quiescent supply current and integrated high- and low-side switches with low on-resistance, which helps to reduce conduction losses.

At the same time, the new AP65x01 devices offer excellent efficiency at low loads because of an automatic light-load algorithm, which is triggered when the inductor’s peak current falls below a pre-set threshold.

The AP65101 and AP65201 buck converters are intended for low-voltage regulation, especially in distributed power architectures. They operate from an input-voltage range of 4.5 to 16V, producing an adjustable output voltage in a range from 0.8V up to 80% of the input voltage.

The converters’ high level of integration and minimal need for external components combined with the small footprint of the TSOT26 package provide valuable cost and board-space savings. Current-mode operation enables fast transient response and easy loop stabilisation.

The device’s Enable pin has a high voltage tolerance of up to 6V.


  • 500kHz switching frequency
  • Over-current limit
  • Over-voltage protection
  • Under-voltage lock-out
  • Thermal shut-down protection


  • Point-of-load power supplies
  • Consumer electronics devices
  • Set-top boxes
  • Coffee machines
  • Access points and gateways
  • Modems