Data Sheet
12V Pico TLynxTM 3A: Non-isolated DC-DC Power Modules
4.5 – 14Vdc input; 0.59Vdc to 5.5Vdc output; 3A output current
January 28, 2010
the module can be achieved by using the Tunable
LoopTM feature described later in this data sheet.
Feature Descriptions
Remote On/Off
The 12V PicoTLynxTM 3A 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.
110
1x10uF External Cap
100
1x47uF External Cap
90
80
70
60
50
40
30
20
10
0
2x47uF External cap
4x47uF External Cap
0.5
1.5
2.5
3.5
4.5
5.5
Output Voltage(Volts)
For positive logic modules, the circuit configuration
for using the On/Off pin is shown in Figure 42. When
the external transistor Q1 is in the OFF state, the
internal PWM Enable signal is pulled high through an
internal 1.5MΩ resistor and the external pullup
resistor and the module is ON. When transistor Q1 is
turned ON, the On/Off pin is pulled low and the
module is OFF. A suggested value for Rpullup is 20kΩ.
Figure 41. Output ripple voltage for various
output voltages with external 1x10 µF, 1x47 µF,
2x47 µF or 4x47 µF ceramic capacitors at the
output (3A 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.
60950-1-03, and VDE 0850:2001-12 (EN60950-1)
Licensed.
VIN+
MODULE
Rpullup
I
1.5MEG
ON/OFF
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.
+
20K
PWM Enable
ON/OFF
GND
V
ON/OFF
Q1
The input to these units is to be provided with a fast-
acting fuse with a maximum rating of 5A in the
positive input lead.
_
Figure 42. Circuit configuration for using positive
On/Off logic.
For negative logic On/Off modules, the circuit
configuration is shown in Fig. 43. The On/Off pin
should be pulled high with an external pull-up resistor
(suggested value for the 4.5V to 14V input range is
20Kohms). When transistor Q2 is in the OFF state,
the On/Off pin is pulled high, transistor Q1 is turned
ON and the module is OFF. To turn the module ON,
Q2 is turned ON pulling the On/Off pin low, turning
transistor Q1 OFF resulting in the PWM Enable pin
going high.
LINEAGE POWER
13
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
