Ultra-Low-Power, Step-Down Switching Regulator Sources 15 mA

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The LTC3620, a high-efficiency, synchronous buck regulator, can deliver up to 15 mA from a very small footprint for applications powered by a single Li-Ion battery. The regulator’s internal synchronous switches deliver efficiencies as high as 95% while Burst Mode operation requires only 18 µA of quiescent current, maximizing battery run time. The LTC3620 accepts inputs from 2.9 V to 5.5 V input and is adjustable to outputs as low as 0.6 V; the LTC3620-1 option is internally programmed to provide a 1.1-V output, eliminating the need for external feedback resistors. The LTC3620’s 2-mm x 2-mm DFN package ensures a very compact solution footprint for a wide array of ultralow power applications. A variable-frequency architecture maximizes efficiency while minimizing noise and keeping out of the audio range. The device’s switching frequency is proportional to the load current, and an internal frequency clamp keeps the minimum switching frequency at light loads above 50 kHz, making it suitable for applications such as Bluetooth headsets, hearing aids, and other applications sensitive to audio interference. Other features include soft-start capability, undervoltage lockout and low-battery detection. Pricing for the LTC3620EDC and LTC3620EDC-1 starts at $1.95 each in lots of 1000. Both versions are available from stock. LINEAR TECHNOLOGY CORP., Milpitas, CA. (408) 432-1900.