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+12V, -12V, +5V, & -5V DC
+5 VDC / +3.3 VDC Power SequencingThe +12 VDC and +5 VDC output levels must be equal to or greater than the +3.3 VDC outputat all times during power-up and normal operation. The time between the +12 VDC or +5 VDCoutput reaching its minimum in-regulation level and +3.3 VDC reaching its minimum in-regulationlevel must be =< 20 ms. PWR_OKPWR_OK is a “power good” signal. It should be asserted high by the power supply to indicatethat the +12 VDC, +5VDC, and +3.3VDC outputs are above the under-voltage thresholds a minimum of 17 ms. and that sufficient mains energy is stored by the converter to guarantee continuous power operation within specification for at least the duration specified, “VoltageHold-up Time.” Conversely, PWR_OK should be de-asserted to a low state when any of the+12 VDC, +5 VDC, or +3.3 VDC output voltages falls below its under-voltage threshold, orwhen mains power has been removed for a time sufficiently long such that power supply operationcannot be guaranteed beyond the power-down warning time. PS_ON#PS_ON# is an active-low, TTL-compatible signal that allows a motherboard to remotely controlthe power supply in conjunction with features such as soft on/off, Wake on LAN*, or wake-onmodem.When PS_ON# is pulled to TTL low, the power supply should turn on the five main DCoutput rails: +12VDC, +5VDC, +3.3VDC, -5VDC, and -12VDC. When PS_ON# is pulled toTTL high or open-circuited, the DC output rails should not deliver current and should be held atzero potential with respect to ground. PS_ON# has no effect on the +5VSB output, which isalways enabled whenever the AC power is present. The power supply shall provide an internal pull-up to TTL high. The power supply shall alsoprovide de-bounce circuitry on PS_ON# to prevent it from oscillating on/off at startup whenactivated by a mechanical switch. The DC output enable circuitry must be SELV-compliant.The power supply shall not latch into a shutdown state when PS_ON# is driven active by pulsesbetween 10ms to 100ms during the decay of the power rails.+5 VSB+5 VSB is a standby supply output that is active whenever the main power is present. It providesa power source for circuits that must remain operational when the five main DC output rails are ina disabled state. Example uses include soft power control, Wake on LAN, wake-on-modem,intrusion detection, or suspend state activities.The +5 VSB output should be capable of delivering a minimum of 2.0 A at +5 V ± 5% toexternal circuits. The power supply must be able to provide the required power during a "wakeup" event. If an external USB device generates the event, there may be peak currents as high as2.5A lasting no more than 500mS.Overcurrent protection is required on the +5 VSB output regardless of the output current rating.This ensures the power supply will not be damaged if external circuits draw more current than thesupply can provide.