www.fairchildsemi.com
FAN5018B
6-Bit VID Controller 2-4 Phase VR10.X Controller
Features
General Description
• Improved Noise Immunity
• Improved Load Line Accuracy
• TTL Compatible VID Inputs
The FAN5018B is a multi-phase DC-DC controller for
implementing high-current, low-voltage, CPU core power
regulation circuits. It is part of a chipset that includes exter-
nal MOSFET drivers and power MOSFETS. The
FAN5018B drives up to four synchronous-rectified buck
channels in parallel. The multi-phase buck converter archi-
tecture uses interleaved switching to multiply ripple fre-
quency by the number of phases and reduce input and output
ripple currents. Lower ripple results in fewer components,
lower component cost, reduced power dissipation, and
smaller board area.
• Fully Pin and Function compatible with existing
FAN5018 and ADP3180 Controllers
• Precision Multi-Phase DC-DC Core Voltage Regulation
– ±14mV Output Voltage Accuracy Over Temperature
• Differential Remote Voltage Sensing
• Selectable 2-, 3-, or 4-Phase Operation
• Selectable VRM9 or VRM10 Operation
• Up to 1MHz per Phase Operation (4MHz ripple
Frequency)
• Lossless Inductor Current Sensing for Loadline
Compensation
The FAN5018B features a high-bandwidth control loop to
provide optimal response to load transients. The FAN5018B
senses current using lossless techniques: Phase current is
measured through each of the output inductors. This current
information is summed, averaged and used to set the loadline
of the output via programmable "droop." The droop is tem-
perature compensated to achieve precise loadline character-
istics over the entire operating range. Additionally,
– External Temperature Compensation
• Accurate Loadline Programming (Meets Intel
®
VRM/VRD10.x CPU Specifications)
• Accurate Channel-Current Balancing for Thermal
Optimization and Layout Compensation
• Convenient 12V Supply Biasing
• 6-bit Voltage Identification (VID) Input
– .8375V to 1.600V in 12.5mV Steps
– Dynamic VID Capability with Fault-Blanking for
glitch-less Output voltage Changes
individual phase current is measured using the R
of
DS(ON)
the low-side MOSFETs. This information is used to dynam-
ically balance/steer per-phase current. The phase currents
are also summed and averaged for over-current detection.
• Adjustable Over Current Protection with Programmable
Latch-Off Delay. Latch-Off Function may be Disabled
• Over-Voltage Protection – Internal OVP Crowbar
Protection
Dynamic-VID technology allows on-the-fly VID changes
with controlled, glitch-less output. Additionally, short-circuit
protection, adjustable current limiting, over-voltage protec-
tion and power-good circuitry combine to ensure reliable and
safe operation. FAN5018B is specified over the commercial
temperature range of 0°C to +85°C and operates from a sin-
gle +12V supply which simplifies design. FAN5018B is
available in a 28L-TSSOP package.
• Package: 28L-TSSOP
Applications
• VRM/VRD 9.x and 10.x Computer DC/DC Converter
• High-Current, Low-Voltage DC/DC Rail
Block Diagram
VIN
Φ1
Φ2
Φ3
Φ4
FAN5009
VOUT
FAN5018B
VIN
FAN5009
REV. 1.0.0 Jul/15/05