SC633

SC633 Fixed 5.3V Output Charge Pump Regulator POWER MANAGEMENT Features             Description The SC633 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 input is greater than 5.3V. Unlike an LDO, dropout is avoided when the input is less than 5.3V. Instead, a charge pump is activated to provide voltage boost and 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 boost regulators. The SC633’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 30mVpp at the output. The SC633 is capable of delivering 275mA continuous current, with peak current to 400mA. A 22µF output capacitor is used for decoupling the load and for smoothing mode transitions. Hysteresis is provided to prevent chatter between charge pump modes. Input voltage range — 2.9V to 5.5V VOUT tolerance — 5.3V ±3% Continuous output current — 275mA, VIN=3V Peak output current — 400mA Three ch...