Data Sheet
12V TLynxTM: Non-isolated DC-DC Power Modules
July 24, 2009
4.5 – 14Vdc input; 0.69Vdc to 5.5Vdc output; 20A output current
external capacitance values at various Vo and for a full
load current of 20A. For stable operation of the
module, limit the capacitance to less than the
Feature Descriptions
Remote Enable
maximum output capacitance as specified in the
electrical specification table. Optimal performance of
the module can be achieved by using the Tunable
The 12V TLynxTM 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.
LoopTM feature described later in this data sheet.
40
1x10uF External Cap
1x47uF External Cap
2x47uF External Cap
4x47uF External Cap
30
20
10
0
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
24.9kΩ 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.
0.5
1.5
2.5
3.5
4.5
5.5
Output Voltage (Volts)
VIN+
MODULE
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 (20A
load). Input voltage is 12V.
Rpullup
24.9K
22K
I
ON/OFF
Q2
PWM Enable
ON/OFF
+
23K
Q3
Safety Considerations
22K
22K
V
ON/OFF
12.1K
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.
Q1
GND
_
Figure 42. Circuit configuration for using positive
On/Off logic.
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.
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 Q1 is in the OFF state, the
On/Off pin is pulled high, internal transistor Q2 is
turned ON and the module is OFF. To turn the module
ON, Q1 is turned ON pulling the On/Off pin low, turning
transistor Q2 OFF resulting in the PWM Enable pin
going high and the module turning ON.
The input to these units is to be provided with a fast-
acting fuse with a maximum rating of 20 A in the
positive input lead.
LINEAGE POWER
14
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
