The AST1S31HF is an internally compensated 2.3 MHz fixed frequency PWM synchronous step-down regulator. The AST1S31HF operates from 2.8 V to 4 V input, while it regulates an output voltage as low as 0.8 V and up to VIN. The AST1S31HF device integrates a 70 mΩ high-side switch and a 55 mΩ synchronous rectifier allowing very high efficiency with very low output voltages. The peak current mode control with internal compensation deliver a very compact solution with a minimum component count. The AST1S31HF is available in a 3 mm x 3 mm, 8-lead VFDFPN package.