In a QFN or MSOP-12E package measuring 3 mm x 3 mm, the LT3645 500-mA, 36V step-down dc/dc converter integrates a low dropout regulator (LDO) and operates with an input range from 3.6V to 36V with transient protection to 55V. An internal 0.75A switch delivers up to 500 mA of continuous output current to voltages as low as 0.8V. The device employs a constant switching frequency of 750 kHz and the LDO is viable for use as an additional output up to 200 mA continuous at voltages as low as 0.8V. Other features include soft start and a shutdown current of less than 2 μA. LINEAR TECHNOLOGY CORP., Milpitas, CA. (800) 454-6327.