ADP3154

a 5-Bit Programmable Dual Power Supply Controller for Pentium® III Processors ADP3154 FUNCTIONAL BLOCK DIAGRAM VCC DRIVE1 DRIVE2 PGND AGND PWRGD SENSE+ SENSE– DELAY NONOVERLAP DRIVE VREF +15% 2R CROWBAR IN OFF CMPI S R gm VREF REFERENCE VLDO CMPT 1.20V OFF-TIME CONTROL VIN SENSE– VID0 VID1 FB R VT1 VREF +5% VREF –5% FEATURES Active Voltage Positioning with Gain and Offset Adjustment Optimal Compensation for Superior Load Transient Response VRM 8.2, VRM 8.3 and VRM 8.4 Compliant 5-Bit Digitally Programmable 1.3 V to 3.5 V Output Dual N-Channel Synchronous Driver Onboard Linear Regulator Controller Total Output Accuracy ؎ 1% Over Temperature High Efficiency, Current-Mode Operation Short Circuit Protection Overvoltage Protection Crowbar Protects Microprocessors with No Additional External Components Power Good Output TSSOP-20 Package APPLICATIONS Desktop PC Power Supplies for: Pentium II and Pentium III Processor Families AMD-K6 Processors VRM Modules GENERAL DESCRIPTION SD Q VT2 CT ADP3154 VID2 VID3 DAC VID4 The ADP3154 is a highly efficient synchronous buck switching regulator controller optimized for converting the 5 V main supply into the core supply voltage required by the Pentium III and other high performance processors. The ADP3154 uses an internal 5-bit DAC to read a voltage identification (VID) code directly from the processor, which is used to set the output voltage between 1.3 V and 3.5 V. The ADP3154 uses a current mode, constant off-time architecture to dr...