NON-ISOLATED DC/DC CONVERTERS
2.4 Vdc - 5.5 Vdc Input, 0.6 Vdc - 3.63 Vdc /6 A Outputs
January 13, 2011
Bel Power, Inc. , a subsidiary of Bel Fuse, Inc.
Input Filtering
The SLIN-06F2Ax modules should be connected to a low ac-impedance source. A highly inductive source can
affect the stability of the module. 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, ceramic capacitors are recommended at the input of the module. Figure A
below shows the input ripple voltage for various output voltages at 6A of load current with 1x22µF or 2x22µF
ceramic capacitors and an input of 5V. Figure B shows data for the 3.3Vin case, with 1x22µF or 2x22µF of
ceramic capacitors at the input.
120
100
80
60
40
20
0
120
100
80
60
40
20
0
1x22uF
2x22uF
1x22uF
2x22uF
0.5
1
1.5
2
2.5
3
0.5
1
1.5
2
2.5
3
3.5
Output Voltage (Vdc)
Figure A
Output Voltage (Vdc)
Figure B
Output Filtering
The SLIN-06F2Ax 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 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 polymer and ceramic capacitors are recommended to improve the dynamic
response of the module. Figure A on the next page provides output ripple information for different external
capacitance values at various Vo and for a load current of 6A while maintaining an input voltage of 5V. Figure B
shows the performance with a 3.3V input. 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 LoopTM feature described later in this data sheet.
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com
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BEL [ BEL FUSE INC. ]
