Data Sheet
March 26, 2008
JHC/JHW350 Power Module; dc-dc Converter
18 – 36Vdc or 36 – 75Vdc Input; 28Vdc Output; 350W
Test Configurations
Design Considerations
Input Source Impedance
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.
Figure 13. Input Reflected Ripple Current Test
Setup.
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 330µF output capacitance placed near output pins
to ensure stable operation in full range of load/line
conditions.
The process of determining the acceptable values of
capacitance and E.S.R. is complex and is load-
dependant. Lineage Power 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
51 mm and 76 mm (2 in. and 3 in.) from the module.
Figure 14. Output Ripple and Noise Test Setup.
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.
Figure 15. Output Voltage and Efficiency Test
Setup.
LINEAGE
POWER.
8
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
