Intel® Server System R2000WF Product Family Technical Product Specification
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Output Voltage
Input Voltage Range
Over Current Limits
+12V
72 A min/78 A max
12VSB
2.5 A min/3.5 A max
3.4.8.2
Over Voltage Protection (OVP)
The power supply over voltage protection shall be locally sensed. The power supply shall shutdown and
latch off after an over voltage condition occurs. This latch shall be cleared by toggling the PSON# signal or
by a DC power interruption. The values are measured at the output of the power supply’s connectors. The
voltage shall never exceed the maximum levels when measured at the power supply connector during any
single point of fail. The voltage shall never trip any lower than the minimum levels when measured at the
power connector. 12 VSB will be auto-recovered after removing OVP limit.
Table 31. Over voltage protection limits
Output Voltage
Minimum (V)
Maximum (V)
+12 V
13.3
14.5
+12 VSB
13.3
14.5
3.4.8.3
Over Temperature Protection (OTP)
The power supply will be protected against over temperature conditions caused by loss of fan cooling or
excessive ambient temperature. In an OTP condition the PSU will shut down. When the power supply
temperature drops to within specified limits, the power supply shall restore power automatically, while the
12 VSB remains always on. The OTP circuit must have built in margin such that the power supply will not
oscillate on and off during a temperature recovering condition. The OTP trip level shall have a minimum of
4 °C of ambient temperature margin.
3.5
Cold Redundancy Support
The power supplies support cold redundancy allowing them to go into a low-power state (that is, a cold
redundant state) in order to provide increased power usage efficiency when system loads are such that both
power supplies are not needed. When the power subsystem is in cold redundant mode, only the needed
power supply to support the best power delivery efficiency is ON. Any additional power supplies, including
the redundant power supply, is in cold standby state.
Each power supply has an additional signal that is dedicated to supporting cold redundancy:
CR_BUS
. This
signal is a common bus between all power supplies in the system.
CR_BUS
is asserted when there is a fault in
any power supply or the power supplies’ output voltages fall below the Vfault threshold. Asserting the
CR_BUS
signal causes all power supplies in cold standby state to power ON.
Enabling power supplies to maintain optimum efficiency is achieved by looking at the load share bus voltage
and comparing it to a programmed voltage level via a
PMBus
command.
Whenever there is no active power supply on the cold redundancy bus driving a HIGH level on the bus, all
power supplies are ON no matter their defined cold redundant roll (active or cold standby). This guarantees
that incorrect programming of the cold redundancy states of the power supply will never cause the power
subsystem to shut down or become over loaded. The default state of the power subsystem is all power
supplies ON. There needs to be at least one power supply in cold redundant active state or standard
redundant state to allow the cold standby state power supplies to go into cold standby state.
3.5.1
Powering on Cold Standby Supplies to Maintain Best Efficiency
Power supplies in cold standby state shall monitor the shared voltage level of the load share signal to sense
when it needs to power on. Depending upon which position (1, 2, or 3) the system defines that power supply
to be in, the cold standby configuration slightly changes the load share threshold that the power supply shall
power on at.
