GE Industrial Solutions 12V Mega TLynx - Manual (Page 10)

Data Sheet
May 4, 2012 12V Mega TLynx TM : Non-Isolated DC-DC Power Modules:
6.0 – 14Vdc Input; 0.8Vdc to 3.63Vdc Output; 30A output current
LINEAGE POWER 10
Test Configurations
TO OSCILLOSCOPE CURRENT PROBE
L TEST
1μH
B
A
TTE
R
Y
C
S
220μF
E.S.R.<0.1 Ω
@ 20°C 100kHz
Min
150μF
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 25. 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 26. 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 27. Output Voltage and Efficiency Test
Setup.
η =
V
O
. I
O
V
IN
. I
IN
x 100 % Efficiency
Design Considerations
The 12V Mega TLynx TM module should be
connected to a low-impedance source. A highly
inductive source can affect the stability of the
module. An input capacitor must be placed directly
adjacent to the input pin of the module, to minimize
input ripple voltage and ensure module stability.
To minimize input voltage ripple, low-ESR ceramic
capacitors are recommended at the input of the
module. Figure 28 shows the input ripple voltage for
various output voltages at 30A of load current with
1x22 µF, 2x22 µF or 2x47 µF ceramic capacitors
and an input of 12V.
In
p
ut
Ri
pp
le
Vo
lta
g
e
(mV
p
-p)
0
50
100
150
200
250
300
350
400
0.5 1 1.5 2 2.5 3
1x22uF
2x22uF
2x47uF
Output Voltage (Vdc)
Figure 28. Input ripple voltage for various
output voltages with 1x22 µF, 2x22 µF or 2x47
µF ceramic capacitors at the input (30A load).
Input voltage is 12V.
Output Filtering
The 12V Mega TLynx modules are designed for low
output ripple voltage and will meet the maximum
output ripple specification with no external
capacitors. 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.
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
ceramic and polymer 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.
Optimal performance of the module can be
achieved by using the Tunable Loop feature
described later in this data sheet.