www.fairchildsemi.com
FAN5094
Multi-Phase Interleaved Buck Converter
Features
Description
• Programmable output from 1.100V to 1.850V in 25mV
steps using an integrated 5-bit DAC
The FAN5094 is a synchronous multi-phase DC-DC
controller IC which provides a highly accurate,
• Two interleaved synchronous phases per IC for maximum
performance
• Up to 4 phase power system
• Built-in current sharing between phases and between ICs
• Frequency and phase synchronization between ICs
• Remote sense and Programmable Active Droop™
• High precision voltage reference
• High speed transient response
• Programmable frequency from 200KHz to 2MHz
• Adaptive delay gate switching
• Integrated high-current gate drivers
• Integrated Power Good, OV, UV, Enable/Soft Start
functions
programmable output voltage for all high-performance
processors. Two interleaved synchronous buck regulator
phases with built-in current sharing operate 180° out of
phase to provide the fast transient response needed to satisfy
high current applications while minimizing external
components. FAN5094s can be paralleled while maintaining
both frequency and phase synchronization and ensuring
current sharing in a high-power system. The FAN5094
features remote voltage sensing, Programmable Active
Droop and advanced response for optimal converter
transient response with minimum output capacitance. It has
integrated high-current gate drivers with adaptive delay gate
switching, eliminating the need for external drive devices.
These make it possible to create power supplies running at a
switching frequency as high as 4MHz, for ultra-high density.
The FAN5094 uses a 5-bit D/A converter to program the
output voltage from 1.100V to 1.850V in 25mV steps with
an accuracy of 0.5%. The FAN5094 uses a high level of
integration to deliver load currents in excess of 150A from a
12V source with minimal external circuitry. The FAN5094
also offers integrated functions including Power Good,
Output Enable/Soft Start, under-voltage lockout, over-
voltage protection, and current limiting with independent
current sense on each phase. It is available in a 28-pin
TSSOP package.
• Drives N-channel MOSFETs
• Operation optimized for 12V operation
• High efficiency mode at light load
• Overcurrent protection using MOSFET sensing
• 28 pin TSSOP package
Applications
• Power supply for Pentium®IV
• Power supply for Athlon®
• Power supply for Ultrasparc™
• VRM for Pentium IV processor
• Programmable step-down power supply
Block Diagram
+12V
VFB
FAN5094
+12V
+
PHASE
VFB
CLK
ISHR
ISHR
Processor
+
+12V
CLK
PHASE
+12V
FAN5094
VFB
Pentium is a registered trademark of Intel Corporation. Athlon is a registered trademark of AMD. Programmable Active Droop is a trademark of Fairchild Semiconductor.
REV. 1.0.2 5/13/02