REFERENCE DESIGN RUNDOWN
ATX
Power Supply Reference Design Meets 80 PLUS Requirements
www.onsemi.com/ATX
ON Semiconductor has unveiled the industry’s first open ATX
reference design certified to meet 80 PLUS performance requirements for
computing applications. The 250W reference design addresses all functional
blocks of the ATX power supply, including power factor correction, switch-mode
power supply control and regulation, post regulation and output rectification.
The design utilizes several of the company's advanced power management devices
and discrete components. A complete documentation package for the ATX reference
design, including description, schematic, bill-of-materials, Gerber images and
evaluation guidelines is available at the above URL as are the verification and
testing report, links to relevant industry information—80 PLUS program,
IEC1000-3-2 requirements, ATX 12 V form factor—and other supporting
information. ON SEMICONDUCTOR, Phoenix, AZ. (800)
282-9855.
Enter No. 335 at www.eepn.com
Key
Components
1. NCP1653:
A compact power factor correction (PFC) controller that is
ideal for continuous conduction mode (CCM) PFC applications. Using this device
to incorporate a PFC front-end into an ATX design reduces parts count and
provides a robust, cost-effective front-end without range switches, the company
says.
2. NCP1280:
An active clamp controller for the switch mode power supply
(SMPS) section of the supply. With soft-switching capability and other unique
features, this device assists in significantly enhancing the efficiency of the
power stage.
3. NCP1014:
A highly integrated regulator for the standby/bias converter
section. This device provides 10W standby power at high-efficiency, with a
lower parts count than existing solutions according to the company.
4. NCP4330:
A synchronous post-regulator that replaces the mag-amp post
regulator to provide higher efficiency in the output section of the supply.
5. NTD110N02R and NTP65N02R:
Low RDS(on) N-channel MOSFETs that provide the
pulse width modulation as part of the NCP4330 post regulator.
What
is 80 PLUS?
80 PLUS is a national buy-down program administered by Ecos
Consulting for desktop computers and desktop-derived servers that contain
highly efficient power supplies. The initiative challenges computer
manufacturers to incorporate internal power supplies that operate at 80%
efficiency or better across several load points. ATX power supplies on the market
today typically operate at 65% efficiency. According to ON Semiconductor, its
ATX reference design prototype was independently tested and verified to comply
with the 80 PLUS program by EPRI Solutions Corp. of Knoxville,
Tennessee. Additionally, the ATX reference design meets IEC1000-3-2 power
factor requirements. The 80 PLUS program is administered by Ecos Consulting on
behalf of several large U.S. power utilities that offer financial incentives to
manufactures to deploy computer and server power supplies that are 80%
efficient or better across several load conditions and are power factor
corrected. For more information about the 80 PLUS program visit www.80PLUS.org.
