Intel® Server Board S2600CW Family TPS
Power Supply Specification Guidelines
Revision 2.4
133
10.2.6.1
PSON# Input Signal
The PSON# signal is required to remotely turn on/off the power supply. PSON# is an active
low signal that turns on the +12V power rail. When this signal is not pulled low by the system,
or left open, the outputs (except the +12VSB) turn off. This signal is pulled to a standby
voltage by a pull-up resistor internal to the power supply. Refer to Table 55 for the timing
diagram.
Table 58. PSON# Signal Characteristic
Signal Type
Accepts an open collector/drain input from the system.
Pull-up to VSB located in power supply.
PSON# = Low
ON
PSON# = High or Open
OFF
MIN
MAX
Logic level low (power supply ON)
0V
1.0V
Logic level high (power supply OFF)
2.0V
3.46V
Source current, Vpson = low
4mA
Power up delay: T
pson_on_delay
5msec
400msec
PWOK delay: T
pson_pwok
50msec
Figure 29. PSON# Required Signal Characteristic
10.2.6.2
PWOK (Power OK) Output Signal
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 de-asserted to a LOW
state. See the following table 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.