Data Sheet
12V Austin LynxTM SMT Non-isolated Power Modules Programmable:
10 – 14Vdc input; 0.75Vdc to 5.5Vdc Output; 10A output current
April 8, 2008
Test Configurations
Design Considerations
Input Filtering
CURRENT PROBE
VIN(+)
TO OSCILLOSCOPE
The 12V Austin Lynx Programmable SMT module should
be connected to a low ac-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.
LTEST
1μH
CIN
CS 1000μF
Electrolytic
2x100μF
Tantalum
E.S.R.<0.1Ω
@ 20°C 100kHz
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.
COM
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.
Figure 23. Input Reflected Ripple Current Test Setup.
COPPER STRIP
VO(+)
COM
RESISTIVE
LOAD
300
250
200
150
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.
10 0
Tantalum
50
Figure 24. Output Ripple and Noise Test Setup.
Ceramic
0
0
1
2
3
4
5
6
Rdistribution Rcontact
Rcontact Rdistribution
VIN(+)
VO
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).
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 25. Output Voltage and Efficiency Test Setup.
VO. IO
Efficiency
=
x
100 %
η
VIN. IIN
LINEAGE POWER
10