VRM 8.2/3/4 Buck Controller With Two Linear Controllers

The ADP3155 is a highly efficient synchronous buck switching regulator controller optimized for converting the 5 V main supply into the core supply voltage required the Pentium III and other high performance processsors. The ADP3155 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 ADP3155 uses a current mode, constant off-time architecture to drive 2 external N-channel MOSFETs at a programmable switching frequency which can be optimized for size and efficiency. It also uses a unique supplemental regulation technique called active voltage positioning to enhance load transient performance.

* Active Voltage Positioning with Gain and Offset Adjustment * Optimal Compensation for Superior Load Transient Response * 5-Bit Digitally Programmable 1.3 V to 3.5 V Output * Dual N-Channel Synchronous Driver * Two Onboard Linear Regulator Controllers * Total Output Accuracy 61% Over Temperature