Intel SPSH4 - Server Platform - 0 MB RAM, Technical Product Specification

Page: 46 / 118

Power supply Subsystem SPSH4 Server System External Product Specification
Revision 1.11 34
4.2.6.3 PSKILL Signal
The PSKILL pin allows for hot swapping of the power supply. The PSKILL pin on the power
supply is shorter than the other signal pins. When a power supply is operating in parallel with
other power supplys and then extracted from the system, the PSKILL pin will quickly turn off the
power supply and prevent arching of the DC output contacts. T
PSKILL
(shown in Table 28) is the
minimum time delay from when PSKILL pin unmates to when the power supply shuts down all
power outputs.
When the PSKILL signal pin is not pulled down or left opened (for example when the power
supply is being extracting from the system), the power supply will shut down regardless of the
condition of the PSON
#
signal. The mating pin of this signal in the system is tied to ground.
Internal to the power supply, the PSKILL pin is connected to a standby voltage through a pull-up
resistor. Upon receiving a LOW state signal at the PSKill pin, the power supply will be allowed to
turn on via the PSON
#
signal. Logic LOW on this pin by itself will not turn on the power outputs.
Table 28: PSKILL Signal Characteristics
Signal Type (Input Signal to Supply) Accepts a ground input from the system. Pull-up to
VSB located in the power supply.
PSKILL = Low, PSON
#
= Low ON
PSKILL = Open, PSON
#
= Low or Open OFF
PSKILL = Low, PSON
#
= Open
OFF
MIN MAX
Logic level low (power supply ON) 0V 1.0V
Logic level high (power supply OFF)
2.0V 5.25V
Source current, Vpskill = low 4ma
Delay from PSKILL=High to power supply
turned off (T
PSKill
)
1
100
µ
sec
Note:
T
PSKill
is the time from the PSKill signal deasserting HIGH to the power supply’s output inductor