GE Industrial Solutions 12A Analog PicoDLynx - Manual (Page 12)

GE
Data Sheet
12A Analog PicoDLynx TM : Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.6Vdc to 5.5Vdc output; 12A Output Current
August 13, 2013 ©2013 General Electric Corporation. All rights reserved. Page 12
Design Considerations
Input Filtering
The 12A Analog 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 12A of load current with 2x22 µF or 3x22 µF ceramic
capacitors and an input of 12V.
Inp
ut R
ip
ple
V
olta
ge
(m
Vp
-p)
Output Voltage (Vdc)
Figure 37. Input ripple voltage for various output
voltages with 2x22 µF or 3x22 µF ceramic capacitors at
the input (12A load). Input voltage is 12V.
Output Filtering
The 12A Analog PicoDLynx TM 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 12A. 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, 2x47 µF or 4x47
µF ceramic capacitors at the output (12A 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 time delay
fuse with a maximum rating of 15 A in the positive input
lead
.
50
100
150
200
250
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
2x22uF
3x22uF
0
10
20
30
40
50
60
0.5 1.5 2.5 3.5 4.5
R
ip
p
le
(
m
V
p
-p
)
Output Voltage(Volts)
1x22uF Ext Cap
1x47uF Ext Cap
2x47uF Ext Cap
4x47uF Ext Cap