FW330 Lineage Power, FW330 Datasheet - Page 17

• Manufacturer Part Number: FW330
• Description: Fw330 Power Modules Dc-dc Converters 36 To 75 Vdc Input, 3.6, 3.3, 2.5, 2.0, Or 1.8 Vdc Output; 180 W To 330 W
• Manufacturer: Lineage Power

April 3, 2008
Feature Descriptions
Power Good Signal
The output undervoltage set-point is adjustable by
using the output undervoltage set-point adjustment pin
(OUSP
external resistor between the OUSP
SENSE(–) pin (see Figure 27). The following equation
determines the required external-resistor value to
obtain a percentage output voltage set-point of ý%.
For 1.8 V:
For 2.0 V:
For 2.5 V:
For 3.3 V:
For 3.6 V:
The test results for this configuration are displayed in
Figure 28. This figure applies to all output voltages.
If not using the output undervoltage set-point adjust
feature, leave the OUSP
OUSP
undervoltage is about half of the nominal output volt-
age.
Figure 27. Circuit Configuration to Adjust the
Lineage Power
R
R
R
R
R
adj
adj
adj
adj
adj
adj
V
ON/O FF
CASE
V
adj
I
I
(+)
(-)
=
=
pin is left open, the set-point of the output
). This is accomplished by connecting an
=
=
=
⎛
⎝
⎛
⎝
⎛
⎝
⎛
⎝
⎛
⎝
Output Undervoltage Set-Point
256
--------------------------- -
241
--------------------------- -
1218
------------------------------ -
1096
------------------------------ -
701
--------------------------- -
Δ% – 61.25
Δ% – 54
Δ% – 50
Δ% – 49
Δ% – 68
SE NSE(+)
S ENSE(-)
–
–
OUSP
–
–
–
Δ%
Δ%
Δ%
V
V
Δ%
Δ%
O
O
(+)
adj
(-)
⎞ kΩ
⎠
⎞ kΩ
⎠
⎞ kΩ
⎠
adj
⎞ kΩ
⎠
⎞ kΩ
⎠
36 to 75 Vdc Input, 3.6, 3.3, 2.5, 2.0, or 1.8 Vdc Output; 180 W to 330 W
(continued)
pin open. When the
(continued)
R
adj
adj
pin and the
R
LO AD
8-2898 (C)
Figure 28. Resistor Selection for Output
There is one situation where the power good signal can
be low even though the module has failed. This can
occur when the module is paralleled with other mod-
ules for additional output power (i.e., the output ORing
diodes would not be used). If one module power train
stops delivering power (fails), the other paralleled mod-
ule(s) would provide a voltage at the output pin of the
failed module. The failed module would then not detect
that its output power was not being delivered. However,
in this situation, the current monitor pins of the paral-
leled modules would indicate that current is not being
delivered from one module and that module had failed.
For redundant applications, the ORing diodes would
keep the other module voltages from being applied to
the failed module output and the power good signal
would indicate a failure.
100k
10k
1M
1k
50
Undervoltage Set-Point Adjustment
% CHANGE IN OUTPUT VOLTAGE (Δ%)
60
3.6 V
2.0 V
70
2.5 V
3.3 V
80
1.8 V
90
8-3067 (F)
100
17