LTC1703 Dual 550kHz Synchronous 2-Phase Switching Regulator Controller with 5-Bit VID FEATURES DESCRIPTIO Side 1 Output Is Compliant with Intel Mobile The LTC 1703 is a dual switching regulator controller opti- VID Specifications (Includes 5-Bit DAC) mized for high efficiency with low input voltages. It includes 0.9V to 2.0V Output Voltage with 25mV/50mV Steps two complete, on-chip, independent switching regulator Two Sides Run Out-of-Phase to Minimize C controllers. Each is designed to drive a pair of external IN Precision Internal 0.8V 1% Reference N-channel MOSFET devices in a voltage mode feedback, Two Independent PWM Controllers in One Package synchronous buck configuration. The LTC1703 includes All N-Channel External MOSFET Architecture digital output voltage adjustment on side 1 that conforms to No External Current Sense Resistor the Intel Mobile VID specification. It uses a constant- 550kHz Switching Frequency Minimizes External frequency, true PWM design switching at 550kHz, minimiz- Component Size ing external component size and cost and optimizing load Very Fast Transient Response transient performance. The synchronous buck architecture Up to 25A Output Current per Channel automatically shifts to discontinuous and then to Burst Low Shutdown Current: < 100A Mode operation as the output load decreases, ensuring Small 28-Pin SSOP Package maximum efficiency over a wide range of load currents. U The LTC1703 features an onboard reference trimmed to 1% APPLICATIO S and delivers better than 1.5% regulation at the converter Mobile Pentium III Processor Systems outputs. An optional latching FAULT mode protects the load Microprocessor Core and I/O Supplies if the output rises 15% above the intended voltage. Each Multiple Logic Supply Generator channel can be enabled independently with both channels High Efficiency Power Conversion disabled, the LTC1703 shuts down and supply current drops , LTC and LT are registered trademarks of Linear Technology Corporation. below 100A. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATIO V IN Dual Output Mobile Pentium III Processor Supply 4.5V TO 5.5V + C IN DCP2 DCP1 QT2 1F 150F MBR0520LT1 MBR0520LT1 10V L1 L2 QT1 2 1H 2.2H V OUT1 LTC1703 V OUT2 0.9V 1 28 1.5V TO 2V PV I CC MAX2 3A QB1B 2 27 15A QB1A CCP1 C32 CCP2 C BOOST1 BOOST2 OUT1 + 1F 3 26 1F 2200pF + C OUT2 180F BG1 BG2 QB2 180F R12 4V 4 25 R32 TG1 TG2 4V 6 R 10.2k 10 IMAX2 5 24 1k SW1 SW2 20k 0.1% R ,18.7k 6 23 IMAX1 GND I PGND MAX1 7 22 RB2 GND FCB FAULT 8 21 11.5k RUN/SS1 RUN/SS2 0.1% 9 20 C GND SS1 COMP1 COMP2 0.22F 10 19 R21 C21 R22, 100k SGND FB2 C11 100k 11 18 15pF C22 C12 FB1 V 220pF CC 12 17 15pF 220pF SENSE VID4 C31 13 16 1703 TA01 VID0 VID3 220pF R31, 10k 14 15 C SS2 VID1 VID2 1F 0.22F VID0 L1: MURATA LQT12535C1R5N12 VID1 L2: COILTRONICS UP2B-2R2 VID2 QT1, QB1A, QB1B: INTERNATIONAL RECTIFIER IRF7811 VID3 QT2, QB2: 1/2 FAIRCHILD NDS8926 VID4 1703fa 1 U ULTC1703 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW ORDER PART Supply Voltage PV 1 28 I NUMBER CC MAX2 V ........................................................................................... 7V CC BOOST1 2 27 BOOST2 3 26 BOOSTn............................................................... 15V BG1 BG2 LTC1703CG TG1 4 25 TG2 BOOSTn SWn .................................................... 7V LTC1703IG 5 24 SW2 SW1 Input Voltage I 6 23 PGND MAX1 7 22 FAULT SWn .......................................................... 1V to 8V FCB RUN/SS1 8 21 RUN/SS2 VIDn ....................................................... 0.3V to 7V 9 20 COMP2 COMP1 All Other Inputs ......................... 0.3V to V + 0.3V CC SGND 10 19 FB2 11 18 V Peak Output Current < 10s FB1 CC SENSE 12 17 VID4 TGn, BGn ............................................................... 5A VID0 13 16 VID3 Operating Temperature Range VID1 14 15 VID2 LTC1703C .............................................. 0C to 85C G PACKAGE LTC1703I........................................... 40C to 85C 28-LEAD PLASTIC SSOP T = 125C, = 55C/ W JMAX JA Storage Temperature Range ................. 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: