TFX12V Power Supply Design Guide
Thin Form Factor with 12 V Connector
Version 2.0
18
2.2.5.1 Energy Star*
The “Energy Star” efficiency requirements of the power supply depend on the intended system configuration.
In the low power / sleep state (S1 or S3) the system should consume power in accordance with the values
listed in
Table 9.
Table 9. Energy Star Input Power Consumption
Maximum Continuous Power Rating of
Power Supply
RMS Watts from the AC Line in Sleep/low-Power
Mode
< 200 W < 15 W
> 200 W < 300 W < 20 W
> 300 W < 350 W < 25 W
> 350 W < 400 W < 30 W
> 400 W 10% of the maximum continuous output rating
Note: To help meet the “Energy Star” system requirements, it is recommended that the power supply have > 50%
efficiency in standby mode.
2.2.6 Other Low Power System Requirements
To help meet the Blue Angel
*
system requirements, RAL-UZ 78, US Presidential executive order 13221,
future EPA requirements, and other low Power system requirements the +5 VSB standby supply efficiency
should be as high as possible. Standby efficiency is measured with the main outputs off (PS_ON# high
state). Standby efficiency should be greater than 50% with a load of 100mA.
2.2.7 Output Ripple/Noise
The output ripple/noise requirements listed in Table 10 should be met throughout the load ranges specified in
Section 2.2.3 and under all input voltage conditions as specified in Section 3.1.
Ripple and noise are defined as periodic or random signals over a frequency band of 10 Hz to 20 MHz.
Measurements shall be made with an oscilloscope with 20 MHz of bandwidth. Outputs should be bypassed at
the connector with a 0.1µF ceramic disk capacitor and a 10µF electrolytic capacitor to simulate system
loading. See Figure 6.
Table 10. DC Output Noise/Ripple
Output
Maximum Ripple and Noise
(mVpp)
+12 V1DC 120
+12 V2DC 200
+5 VDC 50
+3.3 VDC 50
-12 VDC 120
+5 VSB 50
