Data Sheet
JHW250S30R2 Power Module; dc-dc Converter
36 – 75 Vdc Input; 30.2Vdc Output; 250W
October 6, 2005
Design Considerations
Input Source Impedance
Test Configurations
The power module should be connected to a low
ac-impedance source. Highly inductive source
impedance can affect the stability of the power module.
For the test configuration in Figure 13, a 200μF
electrolytic capacitor (ESR<0.7Ω at 100kHz), mounted
close to the power module helps ensure the stability of
the unit. Consult the factory for further application
guidelines.
Output Capacitance
Note: Measure input reflected-ripple current with a simulated
source inductance (LTEST) of 12 µH. Capacitor CS offsets
possible battery impedance. Measure current as shown above.
Output capacitance and load impedance interact with the
power module’s output voltage regulation control system
and may produce an ’unstable’ output condition for the
required values of capacitance and E.S.R. Minimum and
maximum values of output capacitance and of the
capacitor’s associated E.S.R. may be dictated,
depending on the module’s control system. This series
power module requires minimum of 1000µF output
capacitance placed near output pins to ensure stable
operation in full range of load/line conditions.
Figure 13. Input Reflected Ripple Current Test Setup
The process of determining the acceptable values of
capacitance and E.S.R. is complex and is load-
dependant. Tyco provides Web-based tools to assist the
power module end-user in appraising and adjusting the
effect of various load conditions and output capacitances
on specific power modules for various load conditions.
Note: Use a 1.0 µF ceramic capacitor and a 1000µF aluminum
or tantalum capacitor. Scope measurement should be made
using a BNC socket. Position the load between
Safety Considerations
51 mm and 76 mm (2 in. and 3 in.) from the module.
Figure 14. Output Ripple and Noise Test Setup
All Versions - For safety-agency approval of the system
in which the power module is used, the power module
must be installed in compliance with the spacing and
separation requirements of the end-use safety agency
standard, i.e., UL60950, CSA C22.2 No. 60950-00, and
EN 60950 (VDE 0805):2001-12.
“W” Versions only - For end products connected to –48V
dc, or –60Vdc nominal DC MAINS (i.e. central office dc
battery plant), no further fault testing is required. *Note: -
60V dc nominal battery plants are not available in the
U.S. or Canada.
Note: All measurements are taken at the module terminals.
When socketing, place Kelvin connections at module terminals
to avoid measurement errors due to socket contact resistance.
All Versions - For all input voltages, other than DC
MAINS, where the input voltage is less than 60V dc, if
the input meets all of the requirements for SELV, then:
Figure 15. Output Voltage and Efficiency Test Setup
The output may be considered SELV. Output
voltages will remain within SELV limits even with
internally-generated non-SELV voltages. Single
component failure and fault tests were performed
in the power converters.
Tyco Electronics Power Systems
7
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
