SC122 Low Voltage Synchronous Boost Converter POWER MANAGEMENT Features Description Input voltage 0.7V to 1.6V The SC122 is a high efficiency, low noise, synchronous Minimum start-up voltage 0.85V step-up DC-DC converter. It produces a fi xed 3.3V output Output voltage fi xed at 3.3V from a single cell alkaline or NiMH battery. It features an Peak input current limit 350mA typically internal 1.2A switch and synchronous rectifi er to achieve Output current 95mA at V = 1.6V, 50mA at V = 0.9V high effi ciency and to eliminate the need for an external IN IN Effi ciency up to 80% Schottky diode. Internal synchronous rectifi er The SC122 operates exclusively in voltage-hysteretic Switching frequency 1.2MHz power save mode (PSAVE) for high effi ciency under light Power save (voltage hysteretic) control load conditions. It features anti-ringing circuitry for Anti-ringing circuit reduced EMI in noise sensitive applications. While dis- Operating supply current (measured at OUT) 40A abled, the output remains in a high impedance state to No forward conduction path during shutdown preserve the charge on the output capacitor. This permits MLPD-UT-6 1.5 2.0 0.6 (mm) package ultra-low idle quiescent currents in applications in which Lead-free and halogen-free the SC122 can be periodically enabled by an external con- WEEE and RoHS compliant troller to recharge the output capacitor. Applications Low quiescent current is obtained despite a high 1.2MHz Electric toothbrushes operating frequency. Small external components and the Personal medical products space saving MLPD-UT-6, 1.52.00.6 (mm) package, Single-cell alkaline, NiCd, or NiMH applications make this device an excellent choice for small handheld applications that require the longest possible battery life. Typical Application Circuit L1 IN LX Single OUT Cell EN 3.3V (1.2V) GND GND C IN C OUT SC122 February 1, 2010 2010 Semtech Corporation 1SC122 Pin Confi guration Ordering Information Device Package (1)(2) SC122ULTRT MLPD-UT-6 1.52 SC122EVB Evaluation Board 1 LX 6 OUT TOP VIEW Notes: (1) Available in tape and reel only. A reel contains 3,000 devices. GND 2 5 GND (2) Lead-free packaging only. Device is WEEE and compliant and halogen-free. T 3 4 EN IN MLPD-UT 1.52, 6 LEAD = 84C/W JA Marking Information 122 yw MLPD-UT 1.52, 6 LEAD yw = date code 2