Power Conversion Solutions
for powering next generation
microprocessors
January 1997
Pentium (R) is a registered trademark of Intel Corporation
A New Approach from IR
January 1997
• Pentium(R) level microprocessors have created new requirements for high
performance and cost-effective power conversion
• Output voltages dropping to 3.3V and lower...increasing output currents
over 10A...fast transient responses greater than 30A/µsec...all placing
new demands for efficient and low-cost DC/DC converters and power
semiconductors.
• IR’s expertise in both power semiconductors and power conversion circuits
gives us a unique opportunity to work with our customers to address these
needs.
• As a result, we are creating complete power conversion solutions using
state-of-the-art power semiconductors targeted to meet the performance
requirements at the lowest possible cost...and reduce our customers’
design time and effort.
Pentium (R) is a registered trademark of Intel Corporation
• A complete,
turnkey
power supply reference design to meet the
requirements of Pentium Pro(R) microprocessors
– Synchronous buck regulator design operating at 200kHz
– 13A cont. output current, 2.0-3.5V selectable output (via a 4-bit DAC)
– Greater than 92% efficiency
– In excess of 30/µsec transient load response
– Short-circuit protection, over-voltage protection, power good output
– One design meets requirements of all Pentium Pro class processors
(155MHz Pentium all the way up to 266MHz Klamath)
. . . or use lower cost FETs with the same design to save $$$
• All of the above captured in a complete, reference design which includes:
–Complete schematic and board layout (available in Gerber format)
–Demonstration board (evaluated in hi-volume mfg. environment)
–Complete power supply performance evaluation data
–Detailed bill-of-materials with supplier information
–Complete evaluation kit available . . . order as IRP6VRM1-EV January 1997
Power Conversion for
the Pentium (R) Pro
Efficiency easily exceeds 80% across the full output
voltage and current range with a peak over 92%. The output voltage is regulated to within 1%
of 3.5V set point from no load to full load.
Excellent loop characteristics keep the output voltage
within +/-5% under transient load at 100Hz. Low ESL of the output capacitors and good board
design result in output voltage regulation of +/-5%
under transient load at 100kHz.
IRP6VRM1 Performance Results
January 1997
•As a synchronous rectifier, the industry’s first
FETKY
(Gen 5 FET +
Schottky
CoPack
) reduces stray inductance between FET and Schottky
improving efficiency while reducing board space and assembly cost.
•When compared with two SO-8 MOSFETs (Si4410 or IRF7413) in
parallel and one SMB Schottky, the
FETKY
offers similar current-handling
but at 25% lower component cost and only one device to assemble
instead of three!
Use of a FETKY in place of a MOSFET increases
efficiency by 1-2% reducing total losses by up to 25%
Sources of D iscrete
Inductance Solution
Fetky
D2Pak leadframe & wires 6.5nH 3.5nH
PCB traces 3.5nH n/a
SMB leadframe 2nH n/a
Total 12nH 3.5nH
Inductance between the MOSFET and Schottky is
reduced by ~75% compared to a discrete solution
IRL3103D1/S 30V, 0.014ohm Gen 5 Power MOSFET plus
FETKY
TM
30V, 0.42V @ 1A schottky in TO-220/D
2Pak
Efficiency Verses Load Current
85.0%
90.0%
95.0%
100.0%
0.0 2.0 4.0 6.0 8.0 10.0 12.0
Load Current (Amperes)
Efficiency
(%)
MOSFET
FETKY
FETKY
TM
for
Synchronous Rectification
January 1997
