Intel ATX12V manual 3.3.3. +5 VSB, PSON# Signal Characteristics

ATX12V Power Supply Design Guide

Version 2.0

Table 14. PS_ON# Signal Characteristics

	Min.	Max.
VIL, Input Low Voltage	0.0 V	0.8 V
IIL, Input Low Current (Vin = 0.4 V)		-1.6 mA
VIH, Input High Voltage (Iin = -200 µA)	2.0 V
VIH open circuit, Iin = 0		5.25 V

Disable

≤ 0.8 V

PS is

enabled

Enable

Hysteresis ≥ 0.3 V

≥ 2.0 V

PS is

disabled

0.82.0

5.25= Maximum Open- Circuit Voltage

PS_ON# Voltage

Figure 7. PS_ON# Signal Characteristics

3.3.3. +5 VSB

+5 VSB is a standby supply output that is active whenever the AC power is present. It provides a power source for circuits that must remain operational when the five main DC output rails are in a 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% to external circuits. The power supply must be able to provide the required power during a "wake up" event. If an external USB device generates the event, there may be peak currents as high as 2.5A 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 the supply can provide.

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