GE Industrial Solutions 2A PicoTLynx - Manual (Page 13)

GE
Data Sheet
2A PicoTLynx TM : Non-Isolated DC-DC Power Modules
3Vdc –14Vdc input; 0.6Vdc to 5.5Vdc output; 2A Output Current
February 26, 2013 ©2013 General Electric Company. All rights reserved. Page 13
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.
A minimum 22uF External Cap must be used. Figure 52 provides
output ripple information for different external capacitance
values at various Vo and for a load current of 2A. 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.
0
2
4
6
8
10
12
14
0.5 1.5 2.5 3.5 4.5
Output Voltage(Volts)
Ri
p
p
le
(m
V
p
-p
)
1x22uF External Cap
1x47uF External Cap
2x47uF External cap
Figure 52. Output ripple voltage for various output voltages
with external 1x22 µF, 1x47 µF or 2x47 µF ceramic capacitors
at the output (2A 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, CSA
C22.2 No. 60950-1, and DIN EN 60950-1 (VDE 0805 Teil 1):2006-
11
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 4A in the positive input lead.
Feature Descriptions
Remote Enable
The 12V PicoTLynx TM 2A power modules feature an
On/Off pin for remote On/Off operation. Two On/Off logic
options are available. In the Positive Logic On/Off option,
(device code suffix “4” – see Ordering Information), the
module turns ON during a logic High on the On/Off pin
and turns OFF during a logic Low. With the Negative
Logic On/Off option, (no device code suffix, see Ordering
Information), the module turns OFF during logic High and
ON during logic Low. The On/Off signal is always
referenced to ground. For either On/Off logic option,
leaving the On/Off pin disconnected will turn the module
ON when input voltage is present.
For positive logic modules, the circuit configuration for
using the On/Off pin is shown in Figure 53.
Q1
VIN+
GND
+
PWM Enable
ON/OFF
V
ON/OFF
_
MODULE
I
Rpullup
ON/OFF
10K
Q2
10K
50K
50K
Q3
10K
10K
Figure 53. Circuit configuration for using positive
On/Off logic.
For negative logic On/Off modules, the circuit
configuration is shown in Fig. 54.
Q1
ON/OFF
VIN+
GND
+
PWM Enable
V
ON/OFF
_
MODULE
I
Rpullup
ON/OFF
10K
Q2
10K
Figure 54. Circuit configuration for using negative
On/Off logic.
Overcurrent Protection
To provide protection in a fault (output overload)
condition, the unit is equipped with internal
current-limiting circuitry and can endure current limiting