Intel ATX Power Supply Design Guide

Version 0.9

6. Electromagnetic Compatibility

6.1 EMI

The power supply shall comply with CISPR 22, Class B, for both conducted and radiated emissions with a 4 dB margin. Tests shall be conducted using a shielded DC output cable to a shielded load. The load shall be adjusted as follows for three tests: No load on each output; 50% load on each output; and 100% load on each output. Tests will be performed at 100 VAC 50 Hz, 120 VAC 60 Hz, and 220 VAC 50 Hz power.

6.2 Input Line Current Harmonic Content (Optional)

If applicable to sales in Japan or Europe, the power supply shall meet the requirements of EN61000-3-2 Class D and the Guidelines for the Suppression of Harmonics in Appliances and General Use Equipment Class D for harmonic line current content at full rated power.

6.3 Magnetic Leakage Fields

A PFC choke magnetic leakage field shall not cause any interference with a high-resolution computer monitor placed next to or on top of the end use chassis. Final acceptable leakage field strength will be determined by the end system vendor during system level testing in the end use chassis.

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