GE Industrial Solutions Austin Lynx II 12 V SMT - Manual (Page 10)

Data Sheet
October 1, 2009 Austin Lynx TM II 12 V SMT Non-Isolated Power Modules:
8.3 – 14.0Vdc Input; 0.75Vdc to 5.5Vdc Output; 10A output current
LINEAGE POWER 10
Test Configurations
TO OSCILLOSCOPE CURRENT PROBE
L
TEST
1μH
B
A
TTE
R
Y
C S 1000μF
Electrolytic
E.S.R.<0.1 Ω
@ 20°C 100kHz
2x100μF
Tantalum
V IN (+)
COM
NOTE: Measure input reflected ripple current with a simulated
source inductance (L
TEST
) of 1μH. Capacitor C
S
offsets
possible battery impedance. Measure current as shown
above.
C
IN
Figure 23. Input Reflected Ripple Current Test Setup.
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.
V O (+)
COM
1uF .
RESISTIVE
LOAD
SCOPE
COPPER STRIP
GROUND PLANE
10uF
Figure 24. Output Ripple and Noise Test Setup.
V O
COM
V IN (+)
COM
R LOAD
R
contact
R
distribution
R contact R distribution R contact
R
contact
R
distribution
R distribution
V IN
V
O
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 25. Output Voltage and Efficiency Test Setup.
η =
V
O
. I
O
V
IN
. I
IN
x 100 % Efficiency
Design Considerations
Input Filtering
Austin Lynx TM II 12V SMT module should be connected to
a low-impedance AC source. A highly inductive source
can affect the stability of the module. An input
capacitance must be placed directly adjacent to the input
pin of the module, to minimize input ripple voltage and
ensure module stability.
In a typical application, 4x47 µF low-ESR tantalum
capacitors (AVX part #: TPSE476M025R0100, 47µF 25V
100 mΩ ESR tantalum capacitor) will be sufficient to
provide adequate ripple voltage at the input of the
module. To minimize ripple voltage at the input, low
ESR ceramic capacitors are recommended at the input of
the module. Figure 26 shows input ripple voltage (mVp-
p) for various outputs with 4x47 µF tantalum capacitors
and with 4x22 µF ceramic capacitor (TDK part #:
C4532X5R1C226M) at full load.
Inpu
t R
ippl
e Vol
tage
(mVp-
p
)
0
50
100
150
200
250
300
0 1 2 3 4 5 6
Tantalum
Ceramic
Output Voltage (Vdc)
Figure 26. Input ripple voltage for various output
with 4x22 µF polymer and 4x47 µF ceramic capacitors
at the input (full load).