Acoustics
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6
Acoustics
6.1
Acoustics – RECOMMENDED
It is recommended that the power supply be designed with an appropriate fan,
internal impedance, and fan speed control circuitry capable of meeting the acoustic
: Recommended Power Supply Acoustic Targets.
The power supply assembly should not produce, and prominent discrete tone
determined according to ISO 7779, Annex D.
Sound power determination is to be performed at 43 C, at 50% of the maximum rated
load, at sea level. This test point is chosen to represent the environment seen inside a
typical system at the idle acoustic test condition, with the 43 C being derived from the
standard ambient assumption of 23 C, with 20 C added for the temperature rise within
the system (what is typically seen by the inlet fan). The declared sound power shall be
measured according to ISO 7779 and reported according to ISO 9296.
Different customers might have different acoustic specifications. Any power supply
design is recommended to follow any specific customer requirements.
Table 6-1: Recommended Power Supply Acoustic Targets
Idle (BA)
Typical (50% load)
(BA)
Maximum (BA)
Minimum
3.5
4.0
5.0
Target
3.0
3.8
4.5
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Summary of Contents for ATX 3.0
Page 69: ...LFX12V Specific Guidelines 2 0 336521 69 Figure 12 2 Mechanical Details...
Page 70: ...LFX12V Specific Guidelines 2 0 70 336521 Figure 12 3 PSU Slot Feature Detail...
Page 71: ...LFX12V Specific Guidelines 2 0 336521 71 Figure 12 4 Recommended Chassis Tab Feature...
Page 77: ...SFX12V Specific Guidelines 4 0 336521 77 Figure 14 3 Top Mount Fan Profile Mechanical Outline...
Page 82: ...SFX12V Specific Guidelines 4 0 82 336521 Figure 14 10 PS3 Mechanical Outline...
Page 87: ...TFX12V Specific Guidelines 3 0 336521 87 Figure 15 6 Suggested Mounting Tab chassis feature...
