Texas Instruments TPS62745/627451 Ultra-Low Iq Step-Down Converters are a high efficiency ultra-low power synchronous step down converters. These are optimized for low power wireless applications. They provide a regulated output voltage consuming only 400nA quiescent current. Each device operates from two rechargeable Li-Ion batteries (Li-SOCl2, Li-SO2, Li-MnO2) or four to six cell alkaline batteries. The input voltage range up to 10V allows also operation from a USB port and thin-film solar modules. The output voltage is set with four VSEL pins between 1.8V and 3.3V for TPS62745 or 1.3V and 2.8V for TPS627451.