JAW050A and JAW075A Power Modules; dc-dc Converters:
36 Vdc to 75 Vdc Input, 5 Vdc Output; 50 W to 75 W
Data Sheet
April 2008
Output Overvoltage Protection
Feature Descriptions (continued)
To provide protection in an output overvoltage condi-
tion, the unit is equipped with circuitry that monitors the
voltage on the output terminals. If the voltage on the
output terminals exceed the overvoltage protection
threshold, the module enters a hiccup mode of opera-
tion whereby it shuts down and automatically attempts
to restart. As long as the fault persists, the module
remains in this mode.
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 protection mechanism is such that the unit can
continue in this condition until the fault is cleared.
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.
Overtemperature Protection
These modules feature an overtemperature protection
circuit to safeguard against thermal damage. The cir-
cuit shuts down when the maximum case temperature
is exceeded. The module will automatically restart
when the case temperature cools sufficiently.
Thermal Considerations
Introduction
VI(+)
VO(+)
ON/OFF SENSE(+)
CASE
VI(–)
TRIM
SENSE(–)
VO(–)
RLOAD
The power modules operate in a variety of thermal
environments; however, sufficient cooling should be
provided to help ensure reliable operation of the unit.
Heat-dissipating components inside the unit are ther-
mally coupled to the case. Heat is removed by conduc-
tion, convection, and radiation to the surrounding
environment. Proper cooling can be verified by mea-
suring the case temperature. Peak temperature (TC)
occurs at the position indicated in Figure 18.
Radj-down
8-748(F).b
Figure 16. Circuit Configuration to Decrease
Output Voltage
MEASURE CASE
TEMPERATURE HERE
VI(+)
VO(+)
VI(+)
VO(+)
ON/OFF SENSE(+)
Radj-up
ON/OFF
CASE
+ SEN
TRIM
CASE
VI(–)
TRIM
SENSE(–)
VO(–)
RLOAD
– SEN
30.5
(1.20)
V
I
(–)
VO(–)
8-715(F).b
29.0
(1.14)
Figure 17. Circuit Configuration to Increase
Output Voltage
8-716(F).h
Note: Top view, pin locations are for reference only. Measurements
are shown in millimeters and (inches).
Figure 18. Case Temperature Measurement
Location
10
Lineage Power
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
