Demonstration circuit 2012A is a 42V, 3.5A micropower synchronous step-down regulator featuring the LT8610AB. The LT8610AB is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 2.5μA of quiescent current when output is regulated at 5V. The efficiency of the circuit is greater than 90% at light load up to 1.5A. This is a 10% improvement over competing parts. Top and bottom power switches, compensation components and other necessary circuits are inside of the LT8610AB to minimize external components and simplify design.