GE Industrial Solutions Austin MegaLynx - Manual (Page 14)

Data Sheet
April 19, 2011 Austin MegaLynx TM : Non-Isolated DC-DC Power Modules:
4.5 – 5.5Vdc input; 0.8 – 3.63Vdc output; 30A output current
6.0 – 14Vdc input; 0.8 – 5.5Vdc output; 25A output current
LINEAGE POWER 14
Input Under Voltage 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 Austin MegaLynx can be
programmed to any voltage from 0.8dc to 5.0Vdc by
connecting a resistor (shown as Rtrim in Figure 45)
between Trim and GND pins of the module. Without an
external resistor between Trim and GND pins, the output
of the module will be 0.8Vdc. To calculate the value of
the trim resistor, Rtrim for a desired output voltage, use
the following equation:
Ω




−
−
= 100
80 . 0
1200
Vo
Rtrim
Rtrim is the external resistor in Ω
Vo is the desired output voltage
By using a ±0.5% tolerance trim resistor with a TC of
±100ppm, a set point tolerance of ±1.5% can be
achieved as specified in the electrical specification.
Table 1 provides Rtrim values required for some
common output voltages. The POL Programming Tool,
available at
www.lineagepower.com under the Design
Tools section, helps determine the required external trim
resistor needed for a specific output voltage.
V
O
(+)
TRIM
GND
LOAD
V
IN
(+)
ON/OFF
Rtrim
Figure 45. Circuit configuration to program output
voltage using an external resistor.
Table 1
Voltage Margining
Output voltage margining can be implemented in the
Austin MegaLynx modules by connecting a resistor,
R
margin-up
, from the Trim pin to the ground pin for
margining-up the output voltage and by connecting a
resistor, R
margin-down
, from the Trim pin to output pin for
margining-down. Figure 46 shows the circuit
configuration for output voltage margining. The POL
Programming Tool, available at
www.lineagepower.com
under the Design Tools section, also calculates the
values of R
margin-up
and R
margin-down
for a specific output
voltage and % margin. Please consult your local
Lineage Power technical representative for additional
details.
Voltage Sequencing
The Austin MegaLynx series of modules include a
sequencing feature that enables users to implement
various types of output voltage sequencing in their
applications. This is accomplished via an additional
sequencing pin. When not using the sequencing feature,
either leave the SEQ pin unconnected or tied to V
IN
.
Vo
Austin Lynx or
Lynx II Series
GND
Trim
Q1
Rtrim
Rmargin-up
Q2
Rmargin-down
Figure 46. Circuit Configuration for margining
Output voltage.
V
O, set
(V) Rtrim (Ω)
0.8 Open
1.0 5900
1.2 2900
1.5 1614
1.8 1100
2.5 606
3.3 380
5.0 186