Intel Entry Redundant Power 2U ERP2U User Manual
Page 25
 
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.