JFW100G Lineage Power, JFW100G Datasheet - Page 12

• Manufacturer Part Number: JFW100G
• Manufacturer: Lineage Power

dc-dc Converters; 36 to 75 Vdc Input; 2.5 Vdc Output; 25 W to 75 W
Feature Descriptions
Output Voltage Set-Point Adjustment (Trim)
(continued)
Although the output voltage can be increased by both
the remote sense and by the trim, the maximum
increase for the output voltage is not the sum of both.
The maximum increase is the larger of either the
remote sense or the trim. Consult the factory if you
need to increase the output voltage more than the
above limitation.
The amount of power delivered by the module is
defined as the voltage at the output terminals multiplied
by the output current. When using remote sense and
trim, the output voltage of the module can be
increased, which at the same output current would
increase the power output of the module. Care should
be taken to ensure that the maximum output power of
the module remains at or below the maximum rated
power.
Figure 19. Resistor Selection for Increased Output
Output Overvoltage Protection
The output overvoltage shutdown consists of control
circuitry, independent of the primary regulation loop,
that monitors the voltage on the output terminals. The
control loop of the clamp has a higher voltage set point
than the primary loop (see Feature Specifications
table). This provides a redundant voltage control that
reduces the risk of output overvoltage and latches the
converter off if an overvoltage occurs.
12
12
100k
10M
10k
1M
1k
0
Voltage
% CHANGE IN OUTPUT VOLTAGE (Δ%)
2
4
(continued)
6
8
8-2461 (C)
10
Recovery from latched shutdown is accomplished by
cycling the dc input power off for at least 1.0 second or
by toggling the primary or secondary referenced
remote on/off signal for at least 1.0 second.
The overvoltage shutdown set point can be lowered by
placing a resistor between the overvoltage trim
(OVTRIM) pin and SENSE(–) pin. This feature is useful
if the output voltage of the converter has been trimmed
down and a corresponding reduction in overvoltage trip
point is desired.
The resistance required from a given overvoltage nom-
inal set point is derived from the following equation:
Where:
R
V
Module Synchronization
Any module can be synchronized to any other module
or to an external clock using the SYNC IN or SYNC
OUT pins. The modules are not designed to operate in
a master/slave configuration; that is, if one module
fails, the other modules will continue to operate.
SYNC IN Pin
This pin can be connected either to an external clock or
directly to the SYNC OUT pin of another JF-Series or
FW300x module.
If an external clock signal is applied to the SYNC IN
pin, the signal must be a 500 kHz (±50 kHz) square
wave with a 4 Vp-p amplitude. Operation outside this
frequency band will detrimentally affect the perfor-
mance of the module and must be avoided.
If the SYNC IN pin is connected to the SYNC OUT pin
of another module, the connection should be as direct
as possible, and the V
shorted together.
Unused SYNC IN pins should be tied to V
SYNC IN pin is not used, the module will operate from
its own internal clock.
ov-set
ov-adj
R
ov
is the value of an external resistor between the
OVTRIM pin and SENSE(–) pin.
is the nominal adjusted set point of the overvolt-
age shutdown threshold.
-
adj
=
⎛
⎝
4.3 2 V
------------------------------------ -
V
ov-set
–
I
(–) pins of the modules must be
–
ov-set
4.3
⎞ kΩ
⎠
Lineage Power
I
April 2008
(–). If the