GE Industrial Solutions 6A Digital PicoDLynx - Manual (Page 13)

GE
Data Sheet
6A Digital PicoDLynx TM : Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.45Vdc to 5.5Vdc output; 6A Output Current
April 29, 2013 ©2013 General Electric Company. All rights reserved. Page 13
Design Considerations
Input Filtering
The 6A Digital PicoDLynx TM module should be connected
to a low ac-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, ceramic capacitors are
recommended at the input of the module. Figure 37 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.
Figure 37. Input ripple voltage for various output
voltages with 1x22 µF or 2x22 µF ceramic capacitors at
the input (6A load). Input voltage is 12V.
Output Filtering
These modules are designed for low output ripple voltage
and will meet the maximum output ripple specification with
0.1 µF ceramic and 22 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 38 provides output ripple
information for different external capacitance values at
various Vo and a full 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 performance of the module can
be achieved by using the Tunable Loop
TM feature described
later in this data sheet.
Figure 38. Output ripple voltage for various output
voltages with external 1x22 µF, 1x47 µF, or 2x47 µF
ceramic capacitors at the output (6A load). Input voltage
is 12V.
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 60950-1 2nd, CSA C22.2 No. 60950-1-07, DIN EN 60950-
1:2006 + A11 (VDE0805 Teil 1 + A11):2009-11; EN 60950-
1:2006 + A11:2009-03.
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.
The input to these units is to be provided with a fast acting
fuse with a maximum rating of 10A in the positive input lead.
An example of such a fuse is the 318 series from Littelfuse.
70
80
90
100
110
120
130
140
150
160
170
180
190
0.5 1.5 2.5 3.5 4.5
Ri
ppl
e (m
V
p
-p)
Output Voltage(Volts)
1x22uF
2x22uF
0
10
20
30
40
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
R
ip
p
le
(m
V
p
-p
)
Output Voltage(Volts)
1x22uF Ext Cap
1x47uF Ext Cap
2x47uF Ext Cap