Over-Voltage Protection (Ovp); Over-Temperature Protection (Otp); Cold Redundancy Support; Powering On Cold Standby Supplies To Maintain Best Efficiency - Intel R1000GZ Technical Product Specification

3.5.17

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
AC 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 connectors of 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. 12VSB will be auto-recovered after removing OVP limit.
3.5.18

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 shutdown. When the power supply
temperature drops to within specified limits, the power supply shall restore power automatically, while the
12VSB remains always on. The OTP circuit must have built in margin such that the power supply will not
oscillate on and off due to temperature recovering condition. The OTP trip level shall have a minimum of 4°C
of ambient temperature margin.
3.6

Cold Redundancy Support

Power supplies that support cold redundancy can be enabled to go into a low-power state (that is, 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 voltage falls 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 best 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 shutdown 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.
3.6.1

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; will slightly change the load share threshold that the power supply shall
power on at.
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Intel Server System R1000GZ/GL Product Family TPS

Table 16. Over Voltage Protection (OVP) Limits

Output Voltage
+12V
+12VSB
Revision 1.1
MIN (V) MAX (V)
13.3 14.5
13.3 14.5
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signal or by an