The LTC3388EMSE-3#PBF is a 20V high efficiency nanopower Step-down Regulator with internal high side and synchronous power switches that draw only 720nA typical DC supply current at no load while maintaining output voltage regulation. Capable of supplying 50mA of load current, the LTC3388-3 also incorporate an accurate under-voltage lockout (UVLO) feature to disable the converter and maintain a low quiescent current state when the input voltage falls below 2.3V. In regulation, the LTC3388-3 enters a sleep state in which both input and output quiescent currents are minimal. The buck converter turns on and off as needed to maintain regulation. An additional standby mode disables buck switching while the output is in regulation for short duration loads requiring low ripple. Output voltages of 2.8, 3.0, 3.3, 5.0V are pin selectable. The LTC3388-3 can operate with VIN up to 20V while the no load quiescent current remains below 1μA.