SC630A

SC630A 1MHz Fixed 3.3V Output Charge Pump Regulator POWER MANAGEMENT Features            Description The SC630A is a high-current voltage regulator using Semtech’s proprietary low-noise charge pump technology. The charge pump provides a low EMI solution compared to inductive boost regulators. 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 and the head-room needed for regulation. The SC630A’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. Hysteresis is provided to prevent chatter between charge pump modes. When active, the charge pump provides low-ripple operation at 1MHz. Typically the output ripple is 1% of the output voltage — 33mVpp at 215mA. A small 2.2µF capacitor is recommended for all four capacitors. The full rated output current is provided when 2.2µF is used for both bucket capacitors. At the output, a 2.2µF capacitor decouples the load and provides smoothing for mode transitions, while another 2.2µF is used to decouple the input. Input voltage range — 2.95V to 5.5V VOUT tolerance — 3.3V ±3% Continuous out...