Boost regulator offers output disconnect, soft-start in tiny package - Embedded.com

Boost regulator offers output disconnect, soft-start in tiny package

The LTC3526 is a 1-MHz, current-mode, synchronous boost dc-to-dc converter offers an output disconnect and integrated soft-start capability. Its internal 500-mA switches can deliver output voltages as high as 5 V from an input voltage range of 0.85 to 4.4 V, making it suitable for Li-Ion/Polymer or single/multi-cell alkaline/NiMH applications.

Developed by Linear Technology, the LTC3526 can deliver up to 100 mA of continuous output current (at 3.3 V) from a single alkaline cell. Synchronous rectification enables efficiencies of up to 94% while burst mode operation lowers quiescent current to only 9 μA, providing extended battery run-time in handheld applications. The combination of a 2- by 2-mm DFN-6 package and a constant 1-MHz switching frequency minimize both inductor and capacitor sizes.

The LTC3526 uses internal switches with an RDS(on) of 0.40 ω (N-channel) and 0.60 ω (P-channel) to deliver the high efficiencies. The output disconnect feature lets the output be completely discharged in shutdown. It also limits the in-rush of current during start-up, minimizing surge currents seen by the input supply. Additional features include anti-ringing control, short-circuit protection, soft-start, and thermal protection.

For applications demanding the lowest possible noise operation, a LTC3526B version is available with the burst mode disabled. This part runs in continuous mode at all current levels, slightly reducing light load efficiency. However, it minimizes possible interference of switching noise with onboard noise sensitive circuitry.

LTC3526EDC and LTC3526BEDC are both available in 6-lead DFN packages. 1000-piece pricing starts at $1.75 each. For more information, visit www.linear.com.

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