ADP3179

a FEATURES Optimally Compensated Active Voltage Positioning with Gain and Offset Adjustment (ADOPT™) for Superior Load Transient Response Complies with VRM 8.4 Specifications with Lowest System Cost 4-Bit Digitally Programmable 1.3 V to 2.05 V Output N-Channel Synchronous Buck Driver Two On-Board Linear Regulator Controllers Total Accuracy ؎0.8% Over Temperature High Efficiency Current-Mode Operation Short Circuit Protection Power Good Output Overvoltage Protection Crowbar Protects Microprocessors with No Additional External Components APPLICATIONS Core Supply Voltage Generation for: Intel Pentium® III Intel Celeron™ 4-Bit Programmable Synchronous Buck Controllers ADP3159/ADP3179 FUNCTIONAL BLOCK DIAGRAM VCC CT ADP3159/ADP3179 UVLO & BIAS OSCILLATOR SET RESET CROWBAR REFERENCE GND DAC+20% VLR1 LRFB1 LRDRV1 VLR2 LRFB2 LRDRV2 gm COMP REF VID DAC CMP – + CS+ FB PWRGD REF PWM DRIVE DRVL DRVH DAC–20% CS– VID3 VID2 VID1 VID0 GENERAL DESCRIPTION The ADP3159 and ADP3179 are highly efficient output synchronous buck switching regulator controllers optimized for converting a 5 V main supply into the core supply voltage required by high-performance processors. These devices use an internal 4-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 2.05 V. They use a current mode, constant off-time architecture to drive two N-channel MOSFETs at a programmable switching frequency that can be optimize...