Step-Down Regulator Holds Quiescent Current Under 2.5 µA

Thanks to its Burst Mode operation, the LT3970, a 350-mA, 40-V step-down switching regulator with integrated boost and catch diodes, keeps quiescent current under 2.5 µA in no-load standby conditions. The device’s 4.2-V to 40-V input voltage range makes it suitable for automotive and industrial applications. Its internal 550-mA switch can deliver up to 350 mA of continuous output current to voltages as low as 1.21 V. Switching frequency is user programmable from 200 kHz to 2.2 MHz, enabling the designer to optimize efficiency while avoiding critical noise-sensitive frequency bands. The combination of its 10-lead, 3-mm x 2-mm DFN-10 (or MSOP) package and high switching frequency keeps external inductors and capacitors small, providing a very compact, thermally efficient footprint. The LT3970EDDB is packaged in a 2-mm x 3-mm DFN-10, and the LT3970EMS is packaged in a MSOP-10. Prices start at $2.35 and $2.40 each, respectively, in lots of 1000. The LT3970IDDB and LT3970IMS are tested and guaranteed to operate from a -40ºC to 125ºC operating junction temperature and are priced at $2.61 and $2.67 each, respectively, in similar quantities. All versions are available from stock. LINEAR TECHNOLOGY CORP., Milpitas, CA. (408) 432-1900.