Intel ATX Power Supply Design Guide

Version 0.9

3.1.4 Immunity

3.1.4.1 Slow Transients

The DC output(s) shall not exceed the limits specified in Section 3.2.1 as a result of the input power line noise defined in Table 2 under any load condition per EN 61000-4-11.

Table 2: AC Line Voltage Transient Limits

Duration

Sag /

Operating AC Voltage

Line

Performance Criteria

 

Surge

 

Frequency

 

 

 

 

 

 

0 to 500 ms

10%

Rated AC voltages

50/60 Hz

No loss of function or

 

 

 

 

performance

 

 

 

 

 

0 to 15

15%

Mid-point of rated AC

50/60 Hz

No loss of function or

minutes

 

voltages

 

performance

 

 

 

 

 

0 to ½ AC

30%

Mid-point of rated AC

50/60 Hz

No loss of function or

cycle

 

voltages

 

performance

 

 

 

 

 

0 to 5 AC

50%

Mid-point of rated AC

50/60 Hz

Loss of function acceptable,

cycles

sag only

voltages

 

self- recoverable

 

 

 

 

 

3.1.4.2 Surge Voltages

Input Surge Withstand Capability (Line Transients). The power supply shall meet the IEC801-5/IEC 1000-4-5 Level 1, Level 2, and Level 3 criteria for surge withstand capability, with the following conditions and exceptions. The power supply must meet the surge withstand test for the range of operation specified in Section 3.1.

The peak value of the injected unipolar wave form shall be 2.0 kV measured at the input of the power supply for the common and the normal modes of transient surge injection.

The surge withstand test must not produce:

∙Damage to the power supply

∙Disruption of the normal operation of the power supply

∙Output voltage deviation exceeding the limits of Section 3.2.1.

3.1.4.2.1 Surge Immunity, IEC801-5/IEC1000-4-5

No unsafe operation is allowed under any condition. No user-noticeable performance degradation for 1 kV Differential Mode (DM) or 2 kV Common Mode (CM) is allowed. Automatic or manual recovery is allowed for other conditions.

3.1.4.2.2 Electrical Fast Transient / Burst, IEC801-4/IEC1000-4-4

No unsafe operation is allowed under any condition. No user-noticeable performance degradation up to 1 kV is allowed. Automatic or manual recovery is allowed for other conditions.

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