ADP3178 Datasheet | Analog Devices

FEATURES Optimally pensated Active Voltage Positioning with Gain and Offset Adjustment (ADOPT™) for Superior Load Transient Response plies with VRM Specifications with Lowest System Cost 4-Bit Digitally Programmable 1.3 V to 2.05 V Output N-Channel Synchronous Buck Driver Total Accuracy ؎0.8% Over Temperature Two On-Board Linear Regulator Controllers Designed to Meet System Power Sequencing Requirements High Efficiency Current-Mode Operation Short Circuit Protection for Switching Regulator Overvoltage Protection Crowbar Protects Microprocessors with No Additional External ponents APPLICATIONS Core Supply Voltage Generation for: Intel Pentium® III Intel Celeron™ 4-Bit Programmable Synchronous Buck Controllers ADP3158/ADP3178 FUNCTIONAL BLOCK DIAGRAM UVLO & BIAS ADP3158/ ADP3178 OSCILLATOR PWM DRIVE REFERENCE REF DRVH DRVL GND LRFB1 VLR1 LRDRV1 LRFB2 VLR2 LRDRV2 P DAC+20% - + CS- CS+ gm VID DAC VID3 VID2 VID1 VID0 GENERAL DESCRIPTION The ADP3158 and ADP3178 are highly efficient synchronous buck switching regulator controllers optimized for converting a 5 V main supply into the core supply voltage required by highperformance 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 optimized for regulator size and efficiency. The ADP3158 and ADP3178 also use a unique supplemental regulation technique called Analog Devices Optimal Positioning Technology (ADOPT) to enhance load transient performance. Active voltage positioning results in a dc/dc converter that meets the stringent output voltage specifications for highperformance processors, with the minimum number of output capacitors and smallest footprint. Unlike voltage-mode and standard current-mode architectures,...