Technical Product Specification

Intel® Server Chassis SC5650 TPS Power Sub-system

Revision 1.2

Intel order number E39531-004

2.4.9.2 PWOK (Power OK) Output Signal

PWOK is a power OK signal and is 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 de-assert to a LOW state. The start of the

PWOK delay time is inhibited as long as any power supply output is in current limit.

Table 98. PWOK Signal Characteristics

Signal Type

Open collector/drain output from power supply. Pull-up to VSB

located in system.

PWOK = High Power OK

PWOK = Low Power Not OK

MIN MAX

Logic level low voltage, Isink=4mA 0V 0.4V

Logic level high voltage, Isource=200μA

2.4V 5.25V

Sink current, PWOK = low 4mA

Source current, PWOK = high 2mA

PWOK delay: T

pwok_on

100ms 1000ms

PWOK rise and fall time

100μsec

Power down delay: T

pwok_off

1ms 200msec

2.4.9.3 LED

There is a single bi-color LED to indicate power supply status. LED operation is defined in the

following table.

Table 99. LED Indicators

Power Supply Condition LED

No AC power to all power supplies Off

Power supply critical event causing a shutdown: failure, OCP,

OVP, fan fail

Amber

AC present / Only 5VSB on (power supply off) 1-Hz blink Green

Output ON and OK Green

The LED is visible on the power supply’s exterior face. The LED’s location meets ESD

requirements. The LED is securely mounted in such a way that incidental pressure on the LED

will not cause it to be displaced.