Technical Product Specification

Chassis Power Sub-system Intel
®
Server Chassis P4000S Family TPS
Intel order number G22850-006 Revision 1.5
68
2.4.3 Protection Circuits
The PDB shall shut down all the DC/DC converters on the PDB and the power supply (from
PSON) if there is a fault condition on the PDB (OVP or OCP). If the PDB DC/DC converter
latches-off due to a protection circuit tripping, an AC cycle OFF for 15sec min or a PSON# cycle
HIGH for 1sec shall be able to reset the power supply and the PDB.
2.4.3.1 Over-Current Protection (OCP)/240VA Protection
Each DC/DC converter output on PDB has individual OCP protection circuits. The PS+PDB
combo shall shutdown and latch off after an over current condition occurs. This latch shall be
cleared by toggling the PSON
#
signal or by an AC power interruption. The values are measured
at the PDB harness connectors. The DC/DC converters shall not be damaged from repeated
power cycling in this condition. Also, the +12V output from the power supply is divided on the
PDB into 4 channels and +12V4 is limited to 240VA of power. There are current sensors and
limit circuits to shut down the entire PS+PDB combo if the limit is exceeded. The limits are listed
in below table. -12V and 5VSB is protected under over current or shorted conditions so that no
damage can occur to the power supply. Auto-recovery feature is a requirement on 5VSB rail.
Table 90. PDB Over Current Protection Limits/240VA Protection
Output Voltage
Min OCP Trip Limits
Max OCP Trip Limits
Usage
Connectors
+3.3V
18A
240VA
PCIe, Misc
P1
+5V
18A
240VA
PCIe, HDD, Misc
P1, P5-11
+12V1
91A
100A
CPU1 + memory Fans,
Misc
P2
+12V2
18A
20A
HDD and peripherals
P8, 9, 10, 11
+12V3
18A
20A
HDD and peripherals
P5, 6, 7
2.4.3.2 Over Voltage Protection (OVP)
Each DC/DC converter output on PDB have individual OVP protection circuits built in and it shall
be locally sensed. The PS+PDB combo shall shutdown and latches-off after an over voltage
condition occurs. This latch shall be cleared by toggling the PSON
#
signal or by an AC power
interruption. Table 91 contains the over voltage limits. The values are measured at the PDB
harness connectors. The voltage shall never exceed the maximum levels when measured at the
power pins of the output harness connector during any single point of fail. The voltage shall
never trip any lower than the minimum levels when measured at the power pins of the PDB
connector.
Table 91. Over Voltage Protection (OVP) Limits
Output voltage
OVP min (v)
OVP max (v)
+3.3V
3.9
4.8
+5V
5.7
6.5
-12V
-13.3
-15.5
+5VSB
5.7
6.5
2.4.4 PWOK (Power OK) Signal
The PDB connects the PWOK signals from the power supply modules and the DC/DC
converters to a common PWOK signal. This common PWOK signal connects to the PWOK pin
on P1. The DC/DC convert PWOK signals have open collector outputs.