User manual ENHANCE ATX

[. . . ] ATX / ATX12V Power Supply Design Guide Version 1. 1 ATX/ATX12V Power Supply Design Guide Version 1. 1 IMPORTANT INFORMATION AND DISCLAIMERS 1. INTEL CORPORATION (AND ANY CONTRIBUTOR) MAKES NO WARRANTIES WITH REGARD TO THIS DOCUMENT AND IN PARTICULAR DOES NOT WARRANT OR REPRESENT THAT THIS DOCUMENT OR ANY PRODUCTS MADE IN CONFORMANCE WITH IT WILL WORK IN THE INTENDED MANNER. NOR DOES INTEL (OR ANY CONTRIBUTOR) ASSUME RESPONSIBILITY FOR ANY ERRORS THAT THE DOCUMENT MAY CONTAIN OR HAVE ANY LIABILITIES OR OBLIGATIONS FOR DAMAGES INCLUDING, BUT NOT LIMITED TO, SPECIAL, INCIDENTAL, INDIRECT, PUNITIVE, OR CONSEQUENTIAL DAMAGES WHETHER ARISING FROM OR IN CONNECTION WITH THE USE OF THIS DOCUMENT IN ANY WAY. NO REPRESENTATIONS OR WARRANTIES ARE MADE THAT ANY PRODUCT BASED IN WHOLE OR IN PART ON THE ABOVE DOCUMENT WILL BE FREE FROM DEFECTS OR SAFE FOR USE FOR ITS INTENDED PURPOSE. [. . . ] The efficiency of the power supply should be met over the AC input range defined in Table 2, under the load conditions defined in Section 3. 2. 3, and under the temperature and operating conditions defined in Section 5. Energy Star The "Energy Star" efficiency requirements of the power supply depend on the intended system configuration. In the low-power Energy Star state, the AC input power is limited to 30 W or 15% of the rated maximum DC output power for the configuration, whichever is greater. For example, in a 160 W system configuration, the Energy Star input power limit is 160 W × 0. 15 = 24 W 30 W; for a 300 W configuration, 300 W × 0. 15 = 45 W. While a minimum power supply efficiency of 56% is often recommended at Energy Star operating levels, compliance to the guideline will also depend on the system's DC power consumption. In cases where the system Energy Star power consumption for each DC output is known, the system designer should provide this information to assist the power supply designer. Blue Angel, RAL-UZ 78 The +5VSB standby supply efficiency should be a minimum of 50% at 500 mA output. Standby efficiency is measured with the main outputs off and with PS_ON# high. To meet Blue Angel requirements, the AC input power shall not exceed 5 W when the main outputs are in the "DC disabled" state with 500 mA load on +5VSB and a 230 VAC/50 Hz input. Page 14 ATX/ATX12V Power Supply Design Guide Version 1. 1 3. 2. 6. Output Ripple/Noise The output ripple/noise requirements listed in Table 11 should be met throughout the load ranges specified in Section 3. 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 bandwidth. Outputs should be bypassed at the connector with a 0. 1 µF ceramic disk capacitor and a 10 µF electrolytic capacitor to simulate system loading. DC Output Noise/Ripple Output +12 VDC +5 VDC +3. 3 VDC -5 VDC -12 VDC +5 VSB Max. Ripple & Noise (mVpp) 120 50 50 100 120 50 Power Supply AC Hot AC Neutral V out Load V return 10uf 0. 1uf Load must be isolated from the ground of the power supply. AC Ground General Notes: 1. Load the output with its minimum load current. Repeat the measurement with maximum load on the output. Scope Filter Note: 0. 1uf - Kemet, C1206C104K5RAC or equivalent 10uf - United Chemi-con, 293D106X0025D2T or equivalent Scope Note: Use Tektronix TDS460 Oscilloscope or equivalent and a P6046 probe or equivalent. Figure 1. Differential Noise Test Setup Page 15 ATX/ATX12V Power Supply Design Guide Version 1. 1 3. 2. 7. Output Transient Response Table 12 summarizes the expected output transient step sizes for each output. The transient load slew rate is = 1. 0 A/µs. DC Output Transient Step Sizes Output +12 VDC +5 VDC +3. 3 VDC -5 VDC -12 VDC +5 VSB (1) Max. step size (1) (% of rated output amps per Sec 3. 2. 3) 50% 30% 30% Max. [. . . ] Mean Time Between Failures (MTBF) The MTBF of the power supply can be calculated with the Part-Stress Analysis method of MIL-HDBK-217F using the quality factors listed in MIL-HDBK-217F. A target calculated MTBF of the power supply is greater than 100, 000 hours under the following conditions: · Full-rated load · 120 VAC input · Ground benign · 25 °C ambient A target calculated MTBF of the power supply is greater than 30, 000 hours under the following conditions: · Full-rated load · 120 VAC input · Ground benign · 50 °C ambient Page 32 ATX/ATX12V Power Supply Design Guide Version 1. 1 8. Safety The following subsections outline sample product regulations requirements for a typical power supply. Actual requirements will depend on the design, product end use, target geography, and other variables. [. . . ]