Intel Entry Redundant Power 2U ERP2U - Manual (Page 27)

SSI
ERP2U Power Supply Design Guide, V1.0
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8.2 PWOK (Power OK)
STATUS
Required
PWOK is a power OK signal and will be pulled HIGH by the power supply to indicate that all the outputs are within
the regulation limits of the power supply. When any output voltage falls below regulation limits or when AC power
has been removed for a time sufficiently long so that power supply operation is no longer guaranteed, PWOK will
be deasserted to a LOW state. See Figure 3 for a representation of the timing characteristics of PWOK. The
start of the PWOK delay time shall be inhibited as long as any power supply output is in current limit.
Table 24: PWOK Signal Characteristics
Signal Type
Open collector/drain output from power supply. Pull-up
to VSB located in power supply.
PWOK = High
Power OK
PWOK = Low
Power Not OK
MIN MAX
Logic level low voltage, Isink = 4 mA
0 V 0.4 V
Logic level high voltage, Isource=200
µA 2.4 V 5.25 V
Sink current, PWOK = low
4 mA
Source current, PWOK = high
2 mA
PWOK delay: T
pwok_on
200 ms 1000 ms
PWOK rise and fall time
100
µ
s
Power down delay: T
pwok_off
1 ms 200 ms