Power Management Solution

Fairchild Semiconductor International announces the FAN5056MV85 power management integrated circuit (IC) for low-cost desktop computers. The FAN5056MV85 is the first announced IC to comply with the VRM 8.5 specification for Intel Pentium III processors. This IC includes one single-phase, pulse-width modulated (PWM) switching regulator controller to supply the processor core voltage and three linear regulators for other voltages required by the processor and surrounding circuits.

The PWM switching regulator in the FAN5056MV85 is a synchronous-mode DC-DC controller that provides a high accuracy (&#177 0.8%) core voltage of 1.05V to 1.825V in 25mV steps at over 30A according to the voltage identification (VID) code supplied. Programmable Active Droop&#153 provides optimum transient response while minimizing the number of output capacitors. The FAN5056 senses the output current using the R_DS(on) of the external MOSFETs thus eliminating current sense resistors saving board space and reducing system cost.
The FAN5056MV85 also has three linear regulators, each capable of supplying over 2A for V_clock (2.5V), V_Northbridge (1.8V) and V_AGP with Type Detect (selectable 1.5V/3.3V). Additional FAN5056MV85 features include over-voltage, under-voltage, over-current, PowerGood monitors, and thermal shutdown protection.