Demonstration circuit 1382 is a 40V micropower DFN buck regulator featuring the LT®3470A. The LT3470A has a higher peak switch current and improved start-up and dropout compared with the non-"A" version. The demo board is optimized for 3.3V output at up to 250mA load current for a steady state input voltage range of 4V to 36V. With its wide input voltage range, high efficiency internal power switch, extremely low dropout operation, hysteretic current-mode, integrated boost and catch diodes and tiny DFN package, the LT3470A is a very versatile and powerful IC for DC/DC converters that require extremely compact space, high efficiency and high input voltage.