The 171936001 from Wurth Elektronik is a Variable Buck DC-DC Converter that converts an input voltage of 3.5-60 V to an output voltage of 0.85-6 V. It has an efficiency of up to 86%. This DC-DC converter consists of built-in MOSFETs, controller and compensation, and a shielded inductor in a single package. It uses a control scheme mechanism that is based on a current mode (CM) regulation loop and the CM architecture maintains constant frequency during load steps. This converter operates either in selectable forced pulse width modulation (PWM) or PWM/pulse frequency modulation (PFM) mode that allows for optimizing light load efficiency and output voltage ripple. It divides the output voltage using a feedback resistor network and feeds it to the feedback pin. This converter sends this output voltage to the error amplifier for comparing the signal with an internal 0.85 V reference voltage. It generates an amplified error signal and controls the on-time of a fixed frequency pulse width generator, thereby driving the power MOSFETs.  

This buck converter ensures internal compensation and stability with low equivalent series resistance (ESR) output capacitors, which eliminates the need to integrate an external compensation network. It includes protection circuitries that guard against thermal over-stress with thermal shutdown. This RoHS-compliant converter also has over-voltage, over-current, short-circuit, and under-voltage protection circuits to safeguard against electrical damage. It is available in a surface-mount package that measures 8 x 5.5 x 2.3 mm and is ideal for industrial, test and measurement, system power supplies, DSPs, FPGAs, MCU, MPUs, I/O interface power supply, and medical applications.