SC631 Fixed 4.4V Output Charge Pump Regulator POWER MANAGEMENT Features Description Input voltage range 2.9V to 5.5V The SC631 is a high-current voltage regulator using V tolerance 4.4V 3% Semtechs proprietary low-noise charge pump technol- OUT Continuous output current 250mA ogy. Performance is optimized for use in single Li-Ion Peak output current 500mA battery cell applications. The regulator provides the per- Three charge pump modes: 1x, 1.5x and 2x formance of a linear, low drop-out (LDO) voltage regulator Output ripple 30mV for I 400mA when the input is greater than 4.4V. Unlike an LDO, drop- PP OUT Short circuit, over-voltage, and over-temperature out is avoided when the input is less than 4.4V. Instead, a protection charge pump is activated to provide voltage boost and Soft-start functionality the head-room needed for voltage regulation. Shutdown current 0.1A, typical Only two 2.2F bucket capacitors are required to deliver Ultra thin package 2 x 2 x 0.6 (mm) the full output current. The charge pump provides a low Fully WEEE and RoHS compliant EMI solution compared to inductive boost regulators. Applications The SC631s charge pump has three modes of operation: Mobile phones 2x, 1.5x, and 1x modes. The 2x and 1.5x modes deliver Multi-LED backlit LCDs current to the load in each of two phases. The 1x mode PMPs turns off the charge pump, delivering current through an Digital video cameras LDO. When active, the charge pump provides low-ripple Digital still cameras operation at 200kHz, which is typically less than 30mVpp PDAs at the output. The SC631 is capable of delivering 250mA LED camera fl ash continuous current, with peak current to 500mA. A 22F Audio amplifi er power output capacitor 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 effi cient, measuring 2 x 2 x 0.6 (mm). Typical Application Circuit V = 4.4V 250mA OUT IN OUT C C IN OUT V BAT 22 F 22 F SC631 Chip C1+ EN C 1 enable 2.2 F C1- C2+ C 2 GND 2.2 F C2- Patents Pending July 24, 2008 2008 Semtech Corporation 1 SC631 Pin Confi guration Ordering Information Device Package (1)(2) SC631ULTRT MLPD-UT-8 2x2 SC631EVB Evaluation Board Notes: (1) Available in tape and reel only. A reel contains 3,000 devices. GND 1 8 C2- (2) Lead-free package only. Device is WEEE and RoHS compliant. TOP VIEW C1+ 2 7 C2+ C1- 3 6 OUT T IN 5 EN 4 MLPD-UT-8 2x2, 8 LEAD = 68C/W JA Marking Information 631 yw yw = Datecode 2