Data Sheet
Austin LynxTM: SMT Non-Isolated DC-DC Power Modules, Programmable
3.0Vdc – 5.5Vdc input; 0.75Vdc to 3.63Vdc output; 10A Output Current
©2015 General Electric Company. All rights res
erved. Page
Feature Description
Remote On/Off
The Austin LynxTM SMT power modules feature an On/Off pin
for remote On/Off operation. The On/Off pin is an open
collector/drain logic input signal (Von/Off) that is referenced to
ground. Circuit configuration for using the On/Off pin is shown
in Figure 29. During a logic-high (On/Off pin is pulled high
internal to the module) when the transistor Q1 is in the Off
state, the power module is ON. Maximum allowable leakage
current of the transistor when Von/off = VIN,max is 10µA.
Applying a logic-low when the transistor Q1 is turned-On, the
power module is OFF. During this state VOn/Off must be less
than 0.3V. When not using positive logic On/off pin, leave the
pin unconnected or tie to VIN.
Q1
R2
R1 Q2
R3
R4
Q3 CSS
GND
VIN+
ON/OFF
PW M Enable
+
_
ON/OFF
V
I
ON/OFF
MODULE
Figure 29. Circuit configuration for using positive logic
On/OFF.
Remote Sense
The Austin LynxTM SMT power modules offer an option for
Remote Sense feature. When the device code description
includes a suffix “3”, sense pin is added to the module and the
Remote Sense feature is active. See ordering information at
the end of this document for code description.
Remote sense minimizes the effects of distribution losses by
regulating the voltage at the load via Sense and GND pins (see
Figure 30). The voltage between the Sense pin and Vo pin must
not exceed 0.5V. The amount of power delivered by the
module is defined as the output voltage multiplied by the
output current (Vo x Io). When using Remote Sense, the output
voltage of the module can increase, which if the same output is
maintained, increases the power output by the module. Make
sure that the maximum output power of the module remains at
or below the maximum rated power. When the Remote Sense
feature is not being used, tie the Sense pin to output pin.
Figure 32. Remote sense circuit configuration.
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. The typical average output current during
hiccup is 3A.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout limit,
module operation is disabled. The module will begin to operate
at an input voltage above the undervoltage lockout turn-on
threshold.
Overtemperature Protection
To provide protection in a fault condition, the unit is equipped
with a thermal shutdown circuit. The unit will shutdown if the
thermal reference point Tref, exceeds 125oC (typical), but the
thermal shutdown is not intended as a guarantee that the unit
will survive temperatures beyond its rating. The module will
automatically restarts after it cools down.
Output Voltage Programming
The output voltage of the Austin LynxTM SMT can be
programmed to any voltage from 0.75 Vdc to 3.63 Vdc by
connecting a single resistor (shown as Rtrim in Figure 31)
between the TRIM and GND pins of the module. Without an
external resistor between the TRIM pin and the ground, the
output voltage of the module is 0.7525 Vdc. To calculate the
value of the resistor Rtrim for a particular output voltage Vo,
use the following equation:
Ω
−
−
=5110
7525.0
21070
Vo
Rtrim
For example, to program the output voltage of the Austin
LynxTM II module to 1.8 Vdc, Rtrim is calculated is follows:
Ω−
−
=
5110
7525.08.1
21070
Rtrim