The STEVAL-ISA082V1, based on the ST1S40IPHR, is an internally compensated 800 kHz fixed-frequency PWM synchronous stepdown converter evaluation board. The ST1S40 operates from 4.0 V to 18.0 V input, while it regulates an output voltage as low as 0.8 V and up to VIN (100% duty cycle). The ST1S40 integrates a 95 mΩ high-side switch and a 69 mΩ synchronous rectifier allowing very high efficiency with very low output voltage. The peak current mode control with internal compensation delivers a very compact solution with a minimum component count. The ST1S40 is protected through cycle-by-cycle current limiting in case of overload and is also protected by a current foldback function with frequency reduction in case of short-circuit. The device is available with an enable on/off function.