Boost convertor cuts size and consumption

Edited by the Electronicstalk editorial team Jan 8, 2007

1MHz current-mode synchronous boost DC/DC convertor features output disconnect and integrated soft-start capability.

Linear Technology has announced the LTC3526, a 1MHz current-mode synchronous boost DC/DC convertor with output disconnect and integrated soft-start capability.

Its internal 500mA switches can deliver output voltages as high as 5V from an input voltage range of 0.85 to 4.4V, making it ideal for Li-ion/polymer or single/multicell alkaline/NiMH applications.

The LTC3526 can deliver up to 100mA of continuous output current (at 3.3V) from a single alkaline cell.

Synchronous rectification enables efficiencies of up to 94%, and Burst Mode operation lowers quiescent current to only 9uA, providing extended battery run-time in handheld applications.

The combination of a 2 x 2mm DFN-6 package and a constant switching frequency of 1MHz minimise both inductor and capacitor sises, providing a tiny solution footprint required in handheld applications.

The LTC3526 uses internal switches with an on-resistance of only 0.40ohm (N-channel) and 0.60ohm (P-channel) to deliver efficiencies as high as 94%.

The output disconnect feature allows the output to be completely discharged in shutdown.

It also limits the inrush of current during startup, minimising surge currents seen by the input supply.

Additional features include antiringing control, short-circuit protection, soft-start, and thermal protection.

The LTC3526 delivers an ideal solution for boost applications requiring up to 200mA of output current and where a small solution size and low maximum battery run-time are defining factors.

For applications demanding the lowest possible noise operation, a LTC3526B version is available with the Burst Mode feature disabled.

The LTC3526B version runs in continuous mode at all current levels, slightly reducing light load efficiency.

However, it minimises possible interference of switching noise with onboard noise sensitive circuitry.

The LTC3526EDC and LTC3526BEDC are both available from stock in 6-lead DFN packages.

1000-piece pricing starts at US $1.75 each.