SilverStone ST45SF-G - Manual (Page 3)

SFX Form Factor
03
2.3.2 Definition
The ripple voltage of the outputs shall be measured at the pins of the output connector
when terminated in the load impedance specified in figure1.Ripple and noise are
measured at the connectors with a 0.1uF ceramic capacitor and a 10uF electrolytic
capacitor to simulate system loading. Ripple shall be measured under any condition
of line voltage, output load, line frequency, operation temperature.
2.4 Overshoot
Any overshoot at turn on or turn off shall be less 10% of the nominal voltage value, all
outputs shall be within the regulation limit of section 2.0 before issuing the power good
signal of section 5.0.
2.3.3 Ripple voltage test circuit
2.5 Efficiency
Power supply efficiency typical 87% at normal AC main voltage and full load on all outputs.
2.6 Remote on/off control
When the logic level "PS-ON" is low, the DC outputs are to be enabled.
When the logic level is high or open collector, the DC outputs are to be disabled.
Figure 1. Ripple voltage test circuit
2.3.3 Ripple voltage test circuit
AC H o t
AC N e u tra l
Power Supply V o u t
V re tu rn
1 0 u F 0 .1 u F
L o a d
S c o p e
AC G ro u n d
04
3. PROTECTION
3.1 Over-power protection
The power supply will be shutdown and latch off when output power over 110% ~ 160%
of rated DC output.
3.2 Over current protection
The power supply shall have current limit to prevent the +3.3V,+5V,and +12V outputs
from exceeding the values shown in the following Table.If the current limits are exceeded
the power supply shall shutdown and latch off.
3.4 Short circuit
An output short circuit is defined as any output impedance of less than 0.1 ohms.
The power supply shall shut down and latch off for shorting the +3.3 VDC,+5 VDC,
or +12 VDC rails to return or any other rail. Shorts between main output rails and
+5VSB shall not cause any damage to the power supply. The power supply shall
either shut down and latch off or fold back for shorting the negative rails.
+5VSB must be capable of being shorted indefinitely, but when the short is removed,
the power supply shall recover automatically or by cycling PS_ON#. The power supply
shall be capable of withstanding a continuous short-circuit to the output without damage
or overstress to the unit.
3.3 Over voltage protection
The over voltage sense circuitry and reference shall reside in packages that are
separate and distinct from the regulator control circuitry and reference.
No single point fault shall be able to cause a sustained over voltage condition on any
or all outputs. The supply shall provide latch-mode over voltage protection as defined
in Table.
Voltage
+12V
+5V
+3.3V
Over Current Limit (Iout limit)
39A minimum; 49A maximum
20A minimum; 50A maximum
20A minimum; 50A maximum
Output
+12 VDC
+5 VDC
+3.3 VDC
Minimum
13.4
5.74
3.76
Nominal
15.0
6.3
4.2
Maximum
16.5
7.0
5.1
Unit
Volts
Volts
Volts