Technical Product Specification

Intel® Server Board S5520UR and S5520URT TPS Design and Environmental Specifications
Revision 1.9 Intel order number E44031-012
133
9.3.12 Protection Circuits
Protection circuits inside the power supply cause only the power supply’s main outputs to shut
down.
If the power supply latches off due to a protection circuit tripping, an AC cycle OFF for 15
seconds and a PSON
#
cycle HIGH for 1 second is able to reset the power supply.
9.3.12.1 Over-current Protection (OCP)
The power supply has current limits to prevent the +3.3 V, +5 V, and +12 V outputs from
exceeding the values shown in the following table.
If the current limits are exceeded, the power
supply shuts down and latches off.
The latch is cleared by toggling the PSON
#
signal or by an
AC power interruption.
The power supply is not damaged from repeated power cycling in this
condition.
-12 V and 5 VSB are protected under over-current or shorted conditions so that no
damage can occur to the power supply. Auto-recovery feature is a requirement on 5 VSB rail.
Table 82. Over-current Protection (OCP)
Voltage
Over-current Limit (I
out
limit)
+3.3 V
110% minimum (= 22 A) ; 150% maximum (= 30 A)
+5 V
110% min (= 26.4 A); 150% max (= 36 A)
+12 V1 26 A min;
+12 V2 26 A min; 36 A max
+12 V3
18 A min; 20 A max
+12 V4
18 A min; 20 A max
-12 V
0.7 A min; 2.0 A max
5 VSB
115% of rating minimum; 6 A maximum
9.3.12.2 Over-voltage Protection (OVP)
The power supply over-voltage protection is locally sensed. The power supply shuts down and
latches off after an over-voltage condition occurs. This latch is cleared by toggling the PSON
#
signal or by an AC power interruption. The table below contains the over-voltage limits. The
values are measured at the output of the power supply’s connectors. The voltage never
exceeds the maximum levels when measured at the power pins of the power supply connector
during any single point of fail. The voltage never trips any lower than the minimum levels when
measured at the power pins of the power supply connector.
Exception: +5 VSB rail should be able to recover after an over-voltage condition occurs.
Table 83. Over-voltage Protection (OVP) Limits
Output Voltage
Minimum (V)
Maximum (V)
+3.3 V
3.9
4.5
+5 V
5.7
6.2
+12 V1,2, 3, 4
13.3
14.5
-12 V
-13.3
-14.5
+5 VSB
5.7
6.5