Data Sheet
Austin LynxTM 24V: Non-isolated Power Modules:
June 16, 2009
18/20– 30Vdc input; 3.0 – 6.0Vdc & 5.0 – 15.0Vdc Output; 30& 50W
Test Configurations
Design Considerations
Input Filtering
The Austin LynxTM 24V SMT module should be
CURRENT PROBE
TO OSCILLOSCOPE
connected to a low-impedance source. A highly
inductive source can affect the stability of the module.
LTEST
VIN(+)
1μH
An input capacitance must be placed directly adjacent
to the input pin of the module, to minimize input ripple
voltage and ensure module stability.
CIN
CS 220μF
Min
150μF
E.S.R.<0.1Ω
@ 20°C 100kHz
Output Filtering
COM
The Austin LynxTM 24V SMT module is designed for low
NOTE: Measure input reflected ripple current with a simulated
source inductance (LTEST) of 1μH. Capacitor CS offsets
possible battery impedance. Measure current as shown
above.
output ripple voltage and will meet the maximum output
ripple specification with 1 µF ceramic and 10 µF
tantalum capacitors at the output of the module.
However, additional output filtering may be required by
the system designer for a number of reasons. First,
there may be a need to further reduce the output ripple
and noise of the module. Second, the dynamic
response characteristics may need to be customized to
a particular load step change.
Figure 25. Input Reflected Ripple Current Test
Setup.
COPPER STRIP
VO(+)
COM
RESISTIVE
LOAD
To reduce the output ripple and improve the dynamic
response to a step load change, additional capacitance
at the output can be used. Low ESR polymer and
ceramic capacitors are recommended to improve the
dynamic response of the module. For stable operation
of the module, limit the capacitance to less than the
maximum output capacitance as specified in the
electrical specification table.
1uF
.
10uF
SCOPE
GROUND PLANE
NOTE: All voltage measurements to be taken at the module
terminals, as shown above. If sockets are used then
Kelvin connections are required at the module terminals
to avoid measurement errors due to socket contact
resistance.
Safety Considerations
For safety agency approval the power module must be
installed in compliance with the spacing and separation
requirements of the end-use safety agency standards,
i.e., UL 60950, CSA C22.2 No. 60950-00, EN60950
(VDE 0850) (IEC60950, 3rd edition) Licensed.
Figure 26. Output Ripple and Noise Test Setup.
Rdistribution Rcontact
Rcontact Rdistribution
VIN(+)
VO
For the converter output to be considered meeting the
requirements of safety extra-low voltage (SELV), the
input must meet SELV requirements. The power
module has extra-low voltage (ELV) outputs when all
inputs are ELV.
RLOAD
VO
VIN
Rdistribution Rcontact
Rcontact Rdistribution
COM
COM
NOTE: All voltage measurements to be taken at the module
terminals, as shown above. If sockets are used then
Kelvin connections are required at the module terminals
to avoid measurement errors due to socket contact
resistance.
Figure 27. Output Voltage and Efficiency Test Setup.
VO. IO
Efficiency
=
x
100 %
η
VIN. IIN
LINEAGE POWER
10
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
