January 2007
FAN5029
8-Bit Programmable 2- to 5-Phase Synchronous Buck Controller
Description
Features
The FAN5029 is
a multi-phase buck switching
• Selectable 2-, 3-, 4-, or 5-phase operation at up to
regulator controller optimized to convert a 12V input
supply to the processor core voltage required by high-
performance Intel® processors. It has an internal 8-bit
DAC that converts a digital voltage identification (VID)
code that is sent from the processor to set the output
voltage between 0.5V and 1.6V. It outputs a PWM to
external MOSFET drivers that, in turn, drive the
switching power MOSFETs. The switching frequency
of the design is programmable by a single resistor
value and the number of phases can be programmed
to support 2-, 3-, 4-, or 5-phase applications.
1MHz per phase
• ±7.7mV worst-case differential sensing error
• Active current balancing between the output phases
• Power good and crowbar blanking supports on-the-
fly VID code changes
• Selectable VR10 extended (7-bit) and VR11 (8-bit)
VID tables
• Programmable short-circuit protection and latch-off
delay
• Programmable soft start ramp
The FAN5029 also includes programmable no-load
offset and droop functions to adjust the output voltage
as a function of the load current, as required by the
Intel specifications. The FAN5029 also provides an
accurate and reliable short-circuit protection function
with an adjustable over-current set point.
Applications
• Desktop PC/Server processor power supplies for
existing and next generation Intel processors
• VRM modules products
The FAN5029 is specified over the extended
commercial temperature range of 0°C to +85°C and is
available in a 40-lead MLP package.
Part Numbers
• FAN5029MPX is not for new designs.
• The FAN5029MPX_NAAC238 replaces the
FAN5029MPX and is compatible with all VR10 and
VR11 processors.
Ordering Information
Temperature Package
Part Number
Lead
Free
Quantity
per Reel
Packing Method
Range
Type
FAN5029MPX
Not For New Designs
Yes Tape and Reel
FAN5029MPX_NAAC238
0°C to 85°C
MLP-40
3,000
For more information, please contact Ron Berthiaume at ronald.berthiaume@fairchildsemi.com.
© 2004 Fairchild Semiconductor Corporation
FAN5029 Rev. 1.1.3
www.fairchildsemi.com