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 constant-frequency, 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 ModeTM operation as the output load decreases, ensuring maximum efficiency over a wide range of load currents.

FEATURES
■ Two Independent PWM Controllers in One Package
■ 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
■ All N-Channel External MOSFET Architecture
■ No External Current Sense Resistor
■ Precision Internal 0.8V ±1% Reference
■ 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