Power Supply Specification Guidelines
Intel® Server Board S2600CW Family TPS
134
Revision 2.4
Table 59. PWOK Signal Characteristics
Signal Type
Open collector/drain output from power supply.
Pull-up to VSB located in the power supply.
PWOK = High
Power OK
PWOK = Low
Power Not OK
MIN
MAX
Logic level low voltage, Isink=400uA
0V
0.4V
Logic level high voltage, Isource=200
µ
A
2.4V
3.46V
Sink current, PWOK = low
400uA
Source current, PWOK = high
2mA
PWOK delay: T
pwok_on
100ms
1000ms
PWOK rise and fall time
100
µ
sec
Power down delay: T
pwok_off
1ms
200msec
A recommended implementation of the Power Ok circuits is shown below.
Note
: the Power Ok circuits should be compatible with 5V pull up resistor (>10k) and 3.3V pull
up resistor (>6.8k).
10.2.6.3
SMBAlert# Signal
This signal indicates that the power supply is experiencing a problem that the user should
investigate. This shall be asserted due to Critical events or Warning events. The signal shall be
activated in case the critical component temperature reaches a warning threshold, general
failure, over-current, over-voltage, under-voltage, or fan failure. This signal may also indicate
the power supply is reaching its end of life or is operating in an environment exceeding the
specified limits.
This signal is to be asserted in parallel with LED turning solid Amber or blink Amber.
Table 60. SMBAlert# Signal Characteristics
Signal Type (Active Low)
Open collector/drain output from power supply.
Pull-up to VSB located in system.
Alert# = High
OK
Alert# = Low
Power Alert to system
MIN
MAX
Logic level low voltage, Isink=4 mA
0 V
0.4 V
Logic level high voltage, Isink=50
µ
A
3.46 V
Sink current, Alert# = low
4 mA
Sink current, Alert# = high
50
µ
A
Alert# rise and fall time
100
µ
s
