Rev. 11.9.09_44

DS2900

2 of 4

Embedded Power for

Business-Critical Continuity

Logic Control

Remote ON/OFF (PSON#)

The PSON# signal is required to remotely turn on/off the power supply. PSON# is an active low signal that turns on the +12VDC power rail.

When this signal is not pulled low by the system, or left open, the +12VDC output turns off. The 3.30Vsb output remains on. This signal is

pulled to a stanby voltage by a pull-up resistor internal to the power supply. The power supply fan(s) shall operate at the lowest speed

Table 1 PSON# Signal Characteristics

Power Good (PWOK#)

PWOK# is a power good signal and will be pulled LOW by the power supply to indicate that both the outputs are above the regulation limits

of the power supply. When an 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 HIGH state. The start of the PWOK# delay time shall

be inhibited as long as the +12VDC output is in current limit or the 3.30VSB output is below the regulation limit.

Table 2 PWOK# Signal Characteristics

Power Supply Present Indicator (PRESENT#)

The PRESENT# signal is primarily used to provide a mechanism by which the host system can sense the number of power supplies physically

present (operational or not). This pin is connected to ground in the power supply.

AC Input Present Indicator (ACOK#)

The AC OK# signal is used to indicate presence of AC input to the power supply. This signal shall be connected to 3.3 Vsb through a resistor

on the host system side. A logic “Low” level on this signal shall indicate AC input to the power supply is present. A Logic “HIgh” on this signal

shall indiciate a loss of AC input to the power supply.

Table 3 ACOK# Signal Characteristics

Signal Type

Accepts an open collector/drain input from the system. Pulled-up to the

3.30Vsb located in the power supply

PSON# = Low

ON

PSON# = Open

OFF

MIN

MAX

Logic level low (power supply ON)

0 V

0.8 V

Logic level high (power supply OFF)

2.0 V

4.125 V

Source Current, Vpson = low

4 mA

Power up delay: Tpson on delay

5 msec

400 msec

Signal Type:

Open collector/drain output from power supply. Pull-up to 3.30Vsb external to

the power supply

PWOK = High

Power not good

PWOK = Low

Power Good

MIN

MAX

Logic level low voltage, Isink = 4 mA

0 V

0.8 V

Logic level high voltage, Isource = 200 A

2.0 V

4.125 V

Sink current, PWOK = low

4 mA

Source current, PWOK = high

2 mA

PWOK delay: Tpwok on

100 ms

1000 ms

PWOK rise and fall time

100 sec

Power down delay: Tpwok off

1 ms

1000 msec

Signal Type

Pull-up to 3.30Vsb through a resitor in the host system

PRESENT# = Low

Present

PRESENT# = High

Not Present