Ultralow power switching regulator

Linear Technology announces the LTC3620, a high efficiency, synchronous buck regulator which can deliver up to 15mA from a very small footprint for single Li-Ion-powered applications. The internal synchronous switches deliver efficiencies as high as 95% while Burst Mode operation requires only 18uA of quiescent current, maximizing battery run time. The LTC3620 can take a 2.9V-5.5V input, and is adjustable to outputs as low as the 0.6V, whereas the LTC3620-1 option is internally programmed to provide a 1.1V output, eliminating the need for external feedback resistors. The LTC3620s 2mm x 2mm DFN package with only four tiny externals, ensures a very compact solution footprint for a wide array of ultralow power applications.

The LTC3620 uses a unique variable frequency architecture to maximize efficiency while minimizing noise and keeping out of the audio range. Its switching frequency is proportional to the load current, and an internal frequency clamp keeps the minimum switching frequency at light loads above 50KHz making it ideal for applications such as Bluetooth headsets, hearing aids and other applications sensitive to audio interference. The frequency of this clamp is user adjustable by applying an external clock to the FMIN/MODE pin. Other features include soft-start, undervoltage lockout and low-battery detection.
Pricing for the LTC3620EDC and LTC3620EDC-1 start at $1.95 each, for 1,000-piece quantities. Both versions are available from stock.