DESCRIPTION
The LTC®1703 is a dual switching regulator controller optimized for high efficiency with low input voltages. It includes two complete, on-chip, independent switching regulator controllers. Each is designed to drive a pair of external N-channel MOSFET devices in a voltage mode feedback, synchronous buck configuration. The LTC1703 includes digital output voltage adjustment on side 1 that conforms to the Intel Mobile VID specification. It uses a constantfrequency, true PWM design switching at 550kHz, minimizing external component size and cost and optimizing load transient performance. The synchronous buck architecture automatically shifts to discontinuous and then to Burst Mode® operation as the output load decreases, ensuring maximum efficiency over a wide range of load currents.

FEATURES
■ Side 1 Output Is Compliant with Intel Mobile
   VID Specifications (Includes 5-Bit DAC)
■ 0.9V to 2.0V Output Voltage with 25mV/50mV Steps
■ Two Sides Run Out-of-Phase to Minimize CIN
■ Precision Internal 0.8V ±1% Reference
■ Two Independent PWM Controllers in One Package
■ All N-Channel External MOSFET Architecture
■ No External Current Sense Resistor
■ 550kHz Switching Frequency Minimizes External
   Component Size
■ Very Fast Transient Response
■ Up to 25A Output Current per Channel
■ Low Shutdown Current: < 100µA
■ Small 28-Pin SSOP Package

APPLICATIONS
■ Mobile Pentium® III Processor Systems
■ Microprocessor Core and I/O Supplies
■ Multiple Logic Supply Generator
■ High Efficiency Power Conversion