Breakthrough 20V Nanopower Switching Regulator Provides 50mA Output with Only 720nA of Quiescent Current

The LTC3388 utilizes hysteretic synchronous rectification to optimize efficiency over a wide range of load currents. It can offer over 90% efficiency for loads ranging from 15uA to 50mA and only requires 720nA of no load quiescent current in regulation, thereby extending battery life. The combination of a 3mm x 3mm DFN package (or MSOP-10) and only five external components offers a very simple and compact solution footprint for a wide array of low power applications.

The LTC3388 incorporates an accurate undervoltage lock-out feature to disable the converter when the input voltage drops below 2.3V, reducing quiescent current to only 400nA. Once in regulation (at no load), the LTC3388 enters a sleep mode to minimize quiescent current to only 720nA. The buck converter then turns on and off as needed to maintain output regulation. An additional standby mode disables buck switching while the output is in regulation for short duration loads, such as wireless modems, which require low ripple.

This high efficiency, low quiescent current design is ideal for applications such as remote monitors, which require long standby times accompanied by short burst loads for powering sensors and wireless transceivers. The LTC3388 is offered in two different versions, each with different pin-selectable output voltages. The LTC3388-1 offers 1.2V, 1.5V, 1.8V or 2.5V outputs whereas the LTC3388-3 offers 2.8V, 3.0V, 3.3V or 5V outputs.