Description
The device is a power supply controller specifically designed to provide a high performance DC/DC conversion for high current microprocessors. The device implements a dual-phase step-down controller with a 180° phase-shift between each phase. A precise 5-bit digital to analog converter (DAC) allows adjusting the output voltage from 1.100V to 1.850V with 25mV binary steps. The high precision internal reference assures the selected output voltage to be within ±0.8%. The high peak current gate drive affords to have fast switching to the external power mos providing low switching losses. The device assures a fast protection against load over current and load over/under voltage. An internal crowbar is provided turning on the low side mosfet if an over-voltage is detected. In case of over-current, the system works in Constant Current mode. SO-28 ORDERING NUMBERS:L6917BD L6917BDTR (Tape & Reel) 5 BIT PROGRAMMABLE DUAL-PHASE CONTROLLER BLOCK DIAGRAM CURRENT READING CURRENT READING IFB TOTAL CURRENT AVG CURRENT CH 1 OVER CURRENT CH 2 OVER CURRENT DAC DIGITAL SOFT START LOGIC PWM ADAPTIVE ANTI CROSS-CONDUCTION LOGIC PWM ADAPTIVE ANTI CROSS-CONDUCTION CH1 OVER CURRENT CH2 OVER CURRENT LOGIC AND PROTECTIONS 2 PHASE OSCILLATOR PWM1 CURRENT CORRECTION PWM2 CURRENT CORRECTION ERROR AMPLIFIER REMOTE BUFFER 10k 10k 10k LS LS HS Vcc HS BOOT1 UGATE1 PHASE1 LGATE1 ISEN1 PGNDS1 PGND PGNDS2 ISEN2 LGATE2 PHASE2 UGATE2 BOOT2 Vcc COMP FB VSEN FBG FBR VID0 VID1 VID2 VID3 VID4 PGOOD ROSC / INH SGND VCCDR 10k < > + - + + - VCCDR VCC

Features
■ 2 PHASE OPERATION WITH SYNCRHONOUS RECTIFIER CONTROL
■ ULTRA FAST LOAD TRANSIENT RESPONSE
■ INTEGRATED HIGH CURRENT GATE DRIVERS: UP TO 2A GATE CURRENT
■ TTL-COMPATIBLE 5 BIT PROGRAMMABLE OUTPUT COMPLIANT WITH VRM 9.0
■ 0.8% INTERNAL REFERENCE ACCURACY
■ 10% ACTIVE CURRENT SHARING ACCURACY
■ DIGITAL 2048 STEP SOFT-START
■ OVERVOLTAGE PROTECTION
■ OVERCURRENT PROTECTION REALIZED USING THE LOWER MOSFET'S RdsON OR A SENSE RESISTOR
■ 300 kHz INTERNAL OSCILLATOR
■ OSCILLATOR EXTERNALLY ADJUSTABLE UP TO 600kHz
■ POWER GOOD OUTPUT AND INHIBIT FUNCTION
■ REMOTE SENSE BUFFER
■ PACKAGE: SO-28

Applications
■ POWER SUPPLY FOR SERVERS AND WORKSTATIONS
■ POWER SUPPLY FOR HIGH CURRENT MICROPROCESSORS
■ DISTRIBUTED DC-DC CONVERTERS