FW330 Lineage Power, FW330 Datasheet - Page 16

• 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

36 to 75 Vdc Input, 3.6, 3.3, 2.5, 2.0, or 1.8 Vdc Output; 180 W to 330
Feature Descriptions
Module Synchronization
SYNC OUT Pin
This pin contains a clock signal referenced to the V
pin. The frequency of this signal will equal either the
module’s internal clock frequency or the frequency estab-
lished by an external clock applied to the SYNC IN pin.
When synchronizing several modules together, the
modules can be connected in a daisy-chain fashion
where the SYNC OUT pin of one module is connected
to the SYNC IN pin of another module. Each module in
the chain will synchronize to the frequency of the first
module in the chain.
To avoid loading effects, ensure that the SYNC OUT
pin of any one module is connected to the SYNC IN pin
of only one module. Any number of modules can be
synchronized in this daisy-chain fashion.
Overtemperature Protection
These modules feature an overtemperature protection
circuit to safeguard against thermal damage. The cir-
cuit shuts down and latches off the module when the
maximum case temperature is exceeded. The module
can be restarted by cycling the dc input power for at
least 1.0 second or by toggling the remote on/off signal
for at least 1.0 second.
Forced Load Sharing (Parallel Operation)
For either redundant operation or additional power
requirements, the power module can be configured for
parallel operation with forced load sharing (see Figure
26). For a typical redundant configuration, fuses or an
equivalent should be used to protect against short-cir-
cuit conditions. Because of the remote sense, the for-
ward-voltage drops across the fuses do not affect the
set point of the voltage applied to the load. For addi-
tional power requirements, where multiple units are
used to develop combined power in excess of the rated
maximum, the fuses are not needed.
An internal anti-rollback circuit prevents either output
voltage from falling more than 1 V below the other dur-
ing light load operation.
16
16
(continued)
I
(–)
Good layout techniques should be observed for noise
immunity. To implement forced load sharing, the follow-
ing connections must be made:
n
n
n
Figure 26. Wiring Configuration for Redundant
Power Good Signal
The power good signal (PWRGOOD pin) is an open-
collector, secondary-referenced pin that is pulled low
when all five of the following conditions are met:
1. The overvoltage shutdown latch is not set.
2. The thermal shutdown latch is not set.
3. The unit is not in current limit.
4. Secondary internal bias is present.
5. The sensed output voltage is greater than the out-
The parallel pins of all units must be connected
together. The paths of these connections should be
as direct as possible.
All remote-sense pins must be connected to the
power bus at the same point. That is, connect all
remote-sense (+) pins to the (+) side of the power
bus at the same point, and connect all remote-sense
(–) pins to the (–) side of the power bus at the same
point. Close proximity and directness are necessary
for good noise immunity.
Add a 1000 pF capacitor across the PARALLEL pin
and SENSE(–) pin of each module. Locate the
capacitor as close to the module as possible.
put undervoltage set-point.
Parallel Operation
CASE
ON/OFF
V
V
CASE
ON/OFF
V
V
I
I
I
I
(+)
(-)
(+)
(-)
PARALLEL
PARALLEL
SENSE(+)
SENSE(+)
SENSE(-)
SENSE(-)
V
V
V
V
O
O
O
O
(+)
(+)
(-)
(-)
April 3, 2008
Lineage Power
8-581 (C).d