GE Industrial Solutions 12V Austin MicroLynx 5A - Manual (Page 10)

GE
Data Sheet
12V Austin MicroLynx TM 5A: Non-Isolated DC-DC Power Modules
10Vdc –14Vdc input; 0.75Vdc to 5.5Vdc output; 5A Output Current
May 6, 2013 ©2013 General Electric Company. All rights reserved. Page 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
The Austin MicroLynx TM 12V SMT module should be connected
to a low-impedance 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, 2x47 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 2x47 µF tantalum capacitors
and with 2x 22 µF ceramic capacitor (TDK part #:
C4532X5R1C226M) at full load.
Input Rippl
e Vol
tag
e
(m
Vp-
p)
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Ceramic
Tantalum
Output Voltage (Vdc)
Figure 26. Input ripple voltage for various output with 2x47
µF tantalum capacitors and with 2x22 µF ceramic capacitors
at the input (80% of Io,max).