The ADP3170 is a highly efficient output synchronous buck switching regulator controller optimized for converting a 5 V main supply into the core supply voltage required by next generation Intel Celeron processors. The ADP3170 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 1.05 V and 1.825 V. The ADP3170 uses 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 ADP3170 also uses 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 high performance processors, with the minimum number of output capacitors and smallest footprint. Unlike voltage-mode and standard current-