Data Sheet
Naos Raptor 40A Non Isolated Power Module:
July 29, 2009
5 – 13.8Vdc input; 0.6Vdc to 5.0Vdc Output; 40A output current
Test Configurations
Design Considerations
Input Filtering
CURRENT PROBE
TO OSCILLOSCOPE
The Naos Raptor 40A module should be connected
to a low-impedance source. A highly inductive
LTEST
VIN(+)
1μH
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.
CIN
CS 1000μF
Electrolytic
2x100μF
Tantalum
E.S.R.<0.1Ω
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.
@ 20°C 100kHz
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.
160
Figure 37. Input Reflected Ripple Current Test
Setup.
140
120
100
80
1x22uF
2x22uF
COPPER STRIP
VO(+)
COM
RESISTIVE
LOAD
60
1uF
.
10uF
SCOPE
40
20
0
GROUND PLANE
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
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.
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.
Figure 38. Output Ripple and Noise Test Setup.
Rdistribution Rcontact
Rcontact Rdistribution
VIN(+)
VO
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.
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 39. Output Voltage and Efficiency Test
Setup.
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
VO. IO
Efficiency
=
x
100 %
η
VIN. IIN
performance of the module can be achieved by using
LINEAGE POWER
11
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
