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Intel Entry Redundant Power 2U ERP2U User Manual

Page 25

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SSI

ERP2U Power Supply Design Guide, V1.0

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Table 21: Over Current Protection

Voltage

Over Current Limit (Iout limit)

+3.3 V

110% minimum; 150% maximum

+5 V

110% minimum; 150% maximum

+12V1,2,3

Peak current minimum; 20A maximum

7.3 Over Voltage Protection

STATUS

Required

The power supply over voltage protection shall be locally sensed in the hot swap modules. 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 an AC power interruption. Table 22 contains the over voltage limits. 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 pins 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 pins of the power supply connector.

Table 22: Over Voltage Limits

Output Voltage

MIN (V)

MAX (V)

+3.3 V

3.9

4.5

+5 V

5.7

6.5

+12V1,+12V2, +12V3

13.3

14.5

-12 V

-13.3

-14.5

+5 VSB

5.7

6.5

7.4 Over Temperature Protection

STATUS

Recommended

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. The OTP circuit
must have built in hysteresis 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 hysteresis.