St55gf-manual-4.pdf – SilverStone ST55GF Manual User Manual

Page 5

ST55GF

3.2 DC Voltage Regulation, Ripple and Noise

The power supply output voltages must stay within the following voltage limits when
operating at steady state and dynamic loading conditions. All outputs are measured with
reference to the return remote sense (ReturnS) signal. The +5V,+12V, -12V and +5BSB
outputs are measure at the power supply connectors references to ReturnS. The +5V and
+3.3V is measured at its remote sense signal (+5VS+, +3.3VS+) located at the signal
connector.

Table 7 - Regulation, ripple and noise

Ripple and noise shall be measured using the following methods:

a) Measurements made differentially to eliminate common-mode noise
b) Ground lead length of oscilloscope probe shall be • 0.25 inch.
c) Measurements made where the cable connectors attach to the load.
d) Outputs bypassed at the point of measurement with a parallel combination of 10uF

tantalum capacitor in parallel with a 0.1uF ceramic capacitors.

e) Oscilloscope bandwidth of 0 Hz to 20MHz.
f) Measurements measured at locations where remote sense wires are connected.
g) Regulation tolerance shall include temperature change, warm up drift and dynamic load

3.3 Dynamic Loading

The output voltages shall remain within the limits specified in Table 7 for the step loading
and within the limits specified in Table 8 for the capacitive loading. The load transient
repetition rate shall be tested between 50Hz and 5kHz at duty cycle ranging from 10%-90%.
The load transient repetition rate is only a test specification. The

Δstep load may occur

anywhere within the MIN load to the MAX load shown in Table 5 and Table 6.

Table 8 - Transient Load requirements

+5V

+5VSB

+12V

-12V

+3.3V

Output Voltage

+5%/-5%

+10%/-10%

Load Reg.

±1%

Line Reg.

Ripple & Noise

50mV

120mV

Output

Δep Load Size

Load Slew Rate

Capacitive Load

30% of Max.

Load 0.5 A/uS

30% of Max.
30% of Max.
30% of Max.

100uF

1000 uF

2200 uF

+5V

+3.3V

+12V

+5VSB