Data Sheet
Austin MegaLynxTM SMT: Non-Isolated DC-DC Power Modules:
4.5 – 5.5Vdc input; 0.8 to 3.63Vdc Output; 30A output current
6.0 – 14Vdc Input; 0.8Vdc to 3.63Vdc Output; 20/30A output
June 3, 2009
25
Output Filtering
The Austin MegaLynxTM modules are designed for
low output ripple voltage and will meet the
maximum output ripple specification with 0.1 µF
ceramic and 10 µF ceramic capacitors at the output
of the module. 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
1x10uF External Cap
1x47uF External Cap
2x47uF External Cap
4x47uF External Cap
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characteristics may need to be customized to a
particular load step change.
5
0.5
1
1.5
Output Voltage(Volts)
2
2.5
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
polymer and ceramic capacitors are recommended
to improve the dynamic response of the module.
Figure 48 shows the output ripple voltage for
various output voltages at 30A of load current with
different external capacitance values and an input
of 12V. Figure 49 shows data for the 5Vin case for
various output voltages at 30A of load current with
different external capacitance values. For stable
operation of the module, limit the capacitance to
less than the maximum output capacitance as
specified in the electrical specification table.
Figure 49. Output ripple voltage for various
output voltages with external 1x10 µF, 1x47 µF,
2x47 µF or 4x47 µF ceramic capacitors at the
output (30A load). Input voltage is 5V.
Safety Considerations
For safety agency approval the power module must
be installed in compliance with the spacing and
separation requirements of the end-use safety
agency standards, i.e., UL 60950, CSA C22.2 No.
60950-00, EN60950 (VDE 0850) (IEC60950, 3rd
edition) Licensed.
110
100
90
For the converter output to be considered meeting
the requirements of safety extra-low voltage
(SELV), the input must meet SELV requirements.
The power module has extra-low voltage (ELV)
outputs when all inputs are ELV.
80
1x10uF External Cap
1x47uF External Cap
2x47uF External Cap
4x47uF External Cap
70
60
50
40
30
20
10
0
Feature Descriptions
Remote On/Off
0.5
1
1.5
Output Voltage(Volts)
2
2.5
The Austin MegaLynxTM SMT power modules
feature a On/Off pin for remote On/Off operation. If
not using the On/Off pin, connect the pin to ground
Figure 48. Output ripple voltage for various
output voltages with external 1x10 µF, 1x47 µF,
2x47 µF or 4x47 µF ceramic capacitors at the
output (30A load). Input voltage is 12V.
(the module will be ON). The On/Off signal (Von/off
is referenced to ground. Circuit configuration for
remote On/Off operation of the module using the
On/Off pin is shown in Figure 50.
)
During a Logic High on the On/Off pin (transistor Q1
is OFF), the module remains OFF. The external
resistor R1 should be chosen to maintain 3.0V
minimum on the On/Off pin to ensure that the
module is OFF when transistor Q1 is in the OFF
state. Suitable values for R1 are 4.7K for input
voltage of 12V and 3K for 5Vin. During Logic-Low
when Q1 is turned ON, the module is turned ON.
LINEAGE POWER
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LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
