JFW100G Lineage Power, JFW100G Datasheet - Page 13

• Manufacturer Part Number: JFW100G
• Manufacturer: Lineage Power

April 2008
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.
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 20). For a typical redundant configuration,
Schottky diodes or an equivalent should be used to
protect against short-circuit conditions. Because of the
remote sense, the forward-voltage drops across the
Schottky diodes do not affect the set point of the volt-
age applied to the load. For additional power require-
ments, where multiple units are used to develop
combined power in excess of the rated maximum, the
Schottky diodes 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.
Lineage Power
dc-dc Converters; 36 to 75 Vdc Input; 2.5 Vdc Output; 25 W to 75 W
(continued)
(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 20. Wiring Configuration for Redundant
Output Current Monitor
The current monitor (CURMON) pin produces a dc volt-
age proportional to the dc output current of the module.
The voltage is referenced to the secondary SENSE(–)
pin and is typically 4.10 V at rated output current. For
paralleling with FW300x modules, consult the factory
for the V/A ratio. The output impedance of this pin is
approximately 20 k¾, so customer detection circuitry
must have a high-impedance input.
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.
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
(+)
(–)
(+)
(–)
8-581 (C).c
13