LTC3707

FEATURES ■ 180° Phased Dual Controllers Reduce Required Input Capacitance and Power Supply Induced Noise ■ OPTI-LOOP® Compensation Minimizes COUT ■ ±1.5% Output Voltage Accuracy over Temperature ■ Dual N-Channel MOSFET Synchronous Drive ■ Power Good Output Voltage Monitor ■ DC Programmed Fixed Frequency 150kHz to 300kHz ■ Wide VIN Range: 4.5V to 28V Operation ■ Very Low Dropout Operation: 99% Duty Cycle ■ Adjustable Soft-Start Current Ramping ■ Foldback Output Current Limiting ■ Latched Short-Circuit Shutdown with Defeat Option ■ Output Overvoltage Protection ■ Remote Output Voltage Sense ■ Low Shutdown IQ: 20μA ■ 5V and 3.3V Standby Regulators ■ Selectable Constant Frequency, Burst Mode® Operation or PWM Operation ■ Small 28-Lead Narrow SSOP Package APPLICATIONS ■ Notebook and Palmtop Computers, PDAs ■ Battery Chargers ■ Portable Instruments ■ Battery-Operated Digital Devices ■ DC Power Distribution Systems LTC3707 High Efficiency, 2-Phase Synchronous Step-Down Switching Regulator DESCRIPTION The LTC®3707 is a high performance dual step-down switching regulator controller that drives N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows adjustment of the frequency up to 300kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages out of phase. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. ...