GE Industrial Solutions JNC350R Series - Manual (Page 11)

Data Sheet
August 9, 2010
JNC350R Power Modules; DC-DC Converters
18 – 36 Vdc Input; 28Vdc Output; 350W Output
LINEAGE POWER 11
Table 2. Recommended values of R
TUNE
and C
TUNE
to obtain transient deviation of 2% of Vout for a
6A step load with Vin=24V.
Vo 32V 28V 25V 22V 19V 16.8V
C
o
(uF) 1320 1320 1320 1320 1320 1540
R
TUNE
(k
 1000 301 301 301 301 301
C
TUNE
(pF) 470 1500 1500 2200 3300 6800
V(mV) 340 320 280 280 260 290
Please contact your Lineage Power technical
representative to obtain more details of this feature as
well as for guidelines on how to select the right value
of external R-C to tune the module for best transient
performance and stable operation for other output
capacitance values.
Over Temperature Protection
The JNC350R module provides with non-latching over
temperature protection. A temperature sensor
monitors the operating temperature of the converter. If
the reference temperature exceeds a threshold of
110ºC (typical) at the center of the baseplate, the
converter will shut down and disable the output. When
the baseplate temperature has decreased by
approximately 20 ºC the converter will automatically
restart.
The module can be restarted by cycling the dc input
power for at least one second or by toggling the
remote on/off signal for at least one second.
Thermal Considerations
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
thermally coupled to the case. Heat is removed by
conduction, convection, and radiation to the
surrounding environment. Proper cooling can be
verified by measuring the case temperature.
Peak
temperature (T
REF
) occurs at the position indicated in
Figure 19.
Considerations include ambient temperature, airflow,
module power dissipation, and the need for increased
reliability. A reduction in the operating temperature of
the module will result in an increase in reliability. The
thermal data presented here is based on physical
measurements taken in a wind tunnel.
For reliable operation this temperature should not
exceed 100ºC at T
REF
for cold plate. The output power
of the module should not exceed the rated power for
the module as listed in the ordering Information table.
Although the maximum T
REF
temperature of the power
modules is discussed above, you can limit this
temperature to a lower value for extremely high
reliability.
Figure 19. Case (T
REF
) Temperature Measurement
Location (top view).
Thermal Derating
The thermal derating presented in Figure 20 has the
JNC350R module thermally coupled to a cold plate
inside a sealed clamshell chassis, without any internal
air circulation. Please contact your Lineage Power
sales representative for information regarding
applications where the module is cooled by heat
removal into a forced airflow that passes through the
interior of the module and over the top baseplate
and/or attached heatsink.
250
275
300
325
350
375
20 30 40 50 60 70 80 90 100
Baseplate Temperature (C)
O
u
tp
ut P
o
w
e
r (W
)
Figure 20. Output Power Derating for JNC350R in
Conduction cooling (cold plate) applications;
T
a
<70ºC in vicinity of module interior; V
IN
= 24V.