GE Industrial Solutions TLynx - Manual (Page 13)

Data Sheet
August 13, 2013 TLynx TM : Non-isolated DC-DC Power Modules:
2.4 – 5.5Vdc input; 0.6Vdc to 3.63Vdc output; 20A output current
LINEAGE POWER 13
Feature Descriptions
Remote On/Off
The TLynx TM 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 38. When the
external transistor Q1 is in the OFF state, the On/Off pin
is pulled high internally and the module is ON. When
transistor Q1 is turned ON, the On/Off pin is pulled low
and the module is OFF.
6.34K
Q1
GND
ON/OFF
VIN+
_
+
PWM Enable
I
V
ON/OFF
MODULE
ON/OFF Q2
20K
470
Figure 38. Circuit configuration for using positive
On/Off logic.
For negative logic On/Off modules, the circuit
configuration is shown in Fig. 39. The On/Off pin should
be pulled high with an external pull-up resistor
(suggested value for the 2.4V to 5.5Vin range is
8.2Kohms). When transistor Q1 is in the OFF state, the
On/Off pin is pulled high and the module is OFF. The
On/Off threshold for logic High on the On/Off pin
depends on the input voltage and its minimum value is
V
IN
– 1.6V. To turn the module ON, Q1 is turned ON
pulling the On/Off pin low.
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
continuously. At the point of current-limit inception, the
unit enters hiccup mode. The unit operates normally
once the output current is brought back into its specified
range.
6.34K
Q1
GND
PWM Enable
ON/OFF
VIN+
ON/OFF
_
+
I
V
MODULE
Rpullup
470
ON/OFF
3.09K
PTC
Figure 39. Circuit configuration for using negative
On/Off logic.
Overcurrent Protection
To provide protection in a fault condition, the unit is
equipped with a thermal shutdown circuit. The unit will
shutdown if the overtemperature threshold of 144
o C is
exceeded at the thermal reference point T
ref
. The
thermal shutdown is not intended as a guarantee that
the unit will survive temperatures beyond its rating.
Once the unit goes into thermal shutdown it will then
wait to cool before attempting to restart.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout
limit, the module operation is disabled. The module will
begin to operate at an input voltage above the
undervoltage lockout turn-on threshold.
Output Voltage Programming
The output voltage of the TLynx TM module can be
programmed to any voltage from 0.6dc to 3.63Vdc by
connecting a resistor between the Trim+ and GND pins
of the module. Certain restrictions apply on the output
voltage set point depending on the input voltage. These
are shown in the Output Voltage vs. Input Voltage Set
Point Area plot in Fig. 40. The Upper Limit curve shows
that the entire output voltage range is available with the
maximum input voltage of 5.5V. The Lower Limit curve
shows that for output voltages of 1.8V and higher, the
input voltage needs to be larger than the minimum of
2.4V.