Intel ATX12V manual Timing / Housekeeping / Control, Closed-loop Stability, Voltage Hold-up Time

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ATX12V Power Supply Design Guide

Version 2.0

3.2.9. Closed-loop Stability

The power supply shall be unconditionally stable under all line/load/transient load conditions including capacitive loads specified in Section 3.2.8. A minimum of 45 degrees phase margin and 10 dB gain margin is recommended at both the maximum and minimum loads.

3.2.10. +5 VDC / +3.3 VDC Power Sequencing

The +12 VDC and +5 VDC output levels must be equal to or greater than the +3.3 VDC output at all times during power-up and normal operation. The time between the +12 VDC or +5 VDC output reaching its minimum in-regulation level and +3.3 VDC reaching its minimum in-regulation level must be 20 ms.

3.2.11. Voltage Hold-up Time

The power supply should maintain output regulation per Section 3.2.1 despite a loss of input power at the low-end nominal range—115 VAC / 57 Hz or 230 VAC / 47 Hz—at maximum continuous output load as applicable for a minimum of 17 ms.

3.3. Timing / Housekeeping / Control

VAC

 

PS_ON#

 

+12VDC

95%

+3.3VDC+5VDC }O/P's

10%

PWR_OK

T1

T2

T3

T4

T5

~

~

~

~

T6

PWR_OK Sense Level = 95% of nominal

timing_3_5_12b

 

 

Figure 6. Power Supply Timing

Notes: T1 is defined in Section 3.3.4. T2 is defined in Section 3.3.5. T3, T4, T5, and T6 are defined in Table 13

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Contents ATX12V VersionImportant Information and Disclaimers Contents Environmental SafetyMechanical Electromagnetic CompatibilityFigures TablesIncreased +12 VDC output capability IntroductionScope Minimum EfficiencySeparate current limit for 12V2 on the 2x2 connector Main Power ConnectorTerminology Document Title Applicable DocumentsDescription Input Over-current Protection ElectricalAC Input Inrush Current LimitingRegulatory Input Under-voltageOther Certifications and/or Declarations DC Voltage Regulation DC OutputCatastrophic Failure Protection DC Output Voltage RegulationTypical Power Distribution Remote SensingMin Max Power12V power watts Current Output AmpsTypical Power Distribution for a 300 W ATX12V Configuration Cross Loading Graph for 300W ConfigurationTypical Power Distribution for a 350 W ATX12V Configuration Cross Loading Graph for 350W ConfigurationTypical Power Distribution for a 400 W ATX12V Configuration Min Max Peak Current Output AmpsGeneral Power Limit / Hazardous Energy LevelsEfficiency Minimum Efficiency Vs LoadLoading Table for Efficiency Measurements Output Ripple/Noise Energy Star Input Power ConsumptionOther Low Power System Requirements Energy StarDC Output Noise/Ripple Max. Ripple & Noise MVppDC Output Transient Step Sizes Output Transient ResponseCapacitive Load Output Capacitive LoadsClosed-loop Stability 10. +5 VDC / +3.3 VDC Power SequencingTiming / Housekeeping / Control Voltage Hold-up TimePwrok Pwrok Signal CharacteristicsPSON# PSON# Signal Characteristics 3. +5 VSB8. +5 VSB at AC Power-down Power-on TimeReset after Shutdown RisetimeShort-circuit Protection Output ProtectionOver-voltage Protection No-load OperationOver-temperature Protection Output BypassMechanical Physical DimensionsLabeling / Marking Second optional fan may go in this location Second optional Airflow / Fan AC Connector DC Connectors+5V +33V 12V+12V1 +5V ATX Main Power Connector Pin Signal ColorConnector Molex 39-01-2040 or equivalent 2. +12 V Power ConnectorPeripheral Connectors Pin Signal AWG WireWire Signal Serial ATA Power ConnectorFloppy Drive Connector Connector AMP 171822-4 or equivalent Pin Signal AWG WireThermal Shock Shipping TemperatureEnvironmental HumidityRandom Vibration Mechanical ShockAcoustics Emissions Electromagnetic CompatibilityImmunity Magnetic Leakage Fields Input Line Current Harmonic Content and Line FlickerHarmonic Limits, Class D Equipment Reliability Component De-ratingSafety North AmericaInternational Proscribed Materials