Data Sheet
Naos Raptor 6A: Non-isolated DC-DC Power Modules
July 29, 2009
4.5 – 14Vdc input; 0.59Vdc to 6Vdc Output; 6A output current
Test Configurations
Design Considerations
Input Filtering
CURRENT PROBE
TO OSCILLOSCOPE
The Naos Raptor 6A module should be connected to
a low-impedance source. A highly inductive source
LTEST
VIN(+)
1μH
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 or
@ 20°C 100kHz
polymer capacitors are recommended at the input of the
COM
module. Figure 46 shows the input ripple voltage for
various output voltages at 6A of load current with 1x22
µF or 2x22 µF ceramic capacitors and an input of 12V.
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
140
120
100
80
1x22uF
2x22uF
Figure 43. Input Reflected Ripple Current Test
Setup.
COPPER STRIP
60
VO(+)
COM
RESISTIVE
LOAD
40
1uF
.
10uF
SCOPE
20
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
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.
Output Voltage (Vdc)
Figure 46. Input ripple voltage for various output
voltages with 1x22 µF or 2x22 µF ceramic
capacitors at the input (6A load). Input voltage is
12V.
Figure 44. Output Ripple and Noise Test Setup.
Rdistribution Rcontact
Rcontact Rdistribution
VIN(+)
VO
Output Filtering
RLOAD
VO
The Naos Raptor 6A 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.
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 45. 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. Figure 47 provides output
ripple information for different external capacitance
values at various Vo and for a load current of 6A. 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
LINEAGE POWER
12
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
