Tiny 400mA Buck-Boost Charge Pump Regulator

Tiny 400mA Buck-Boost Charge Pump Regulator

The SC630 is a high-current voltage regulator using Semtech’s proprietary low-noise charge pump technology.

Performance is optimized for use in single Li-Ion battery cell applications. The regulator provides the performance of a linear, low drop-out (LDO) voltage regulator when the battery is greater than 3.3V. Unlike an LDO, drop-out is avoided when the battery is less than 3.3V. Instead, a charge pump is activated to provide voltage boost — the head-room needed for voltage regulation.

Only two 2.2μF bucket capacitors are required to deliver the full output current. The charge pump provides a low EMI solution compared to inductive buck/boost regulators.

The SC630’s charge pump has three modes of operation: 2x, 1.5x, and 1x modes. The 2x and 1.5x modes deliver current to the load in each of two phases. The 1x mode turns off the charge pump, delivering current through an LDO. When active, the charge pump provides low-ripple operation at 200kHz, which is typically less than 20mVpp at the output. 

The SC630 is capable of delivering 400mA continuous current, with peak current to 500mA. A 22μF output capacitor of is used for decoupling the load and for smoothing mode transitions. Hysteresis is provided to prevent chatter between charge pump modes.

The micro lead-frame package is both small and thermally efficient, measuring 2 x 2 x 0.6 (mm).

Samples are available today - click on the link below for details.