Data Sheet
July 11, 2011
Naos Raptor 40A Non Isolated Power Module:
5 – 13.8Vdc input; 0.6Vdc to 5.0Vdc Output; 40A output current
LINEAGE POWER 11
Test Configurations
TO OSCILLOSCOPE
CURRENT PROBE
L
TEST
1μH
BATTERY
C
S
1000μF
Electrolytic
E.S.R.<0.1Ω
@ 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 37. 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 38. Output Ripple and Noise Test Setup.
V
O
COM
V
IN
(+)
COM
R
LOAD
R
contac t
R
distribution
R
contac t
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 39. Output Voltage and Efficiency Test
Setup.
η
=
V
O
. I
O
V
IN
. I
IN
x
100
%
Efficiency
Design Considerations
Input Filtering
The Naos Raptor 40A 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.
To minimize input voltage ripple, low-ESR ceramic
capacitors are recommended at the input of the
module. Figure 40 shows the input ripple voltage for
various output voltages at 40A of load current with
1x22 µF or 2x22 µF ceramic capacitors and an input
of 12V.
Input Ripple Voltage (mVp-p)
0
50
100
150
200
250
300
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
1x22uF
2x22uF
Output Voltage (Vdc)
Figure 40. Input ripple voltage for various output
voltages with 1x22 µF or 2x22 µF ceramic
capacitors at the input (40A load). Input voltage is
12V.
Output Filtering
The Naos Raptor 40A 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
TM
feature described later in this
data sheet.
