GE Industrial Solutions Austin Microlynx II SMT - Manual (Page 13)

Data Sheet
September 10, 2013 Austin MicroLynx TM II SMT Non-isolated Power Modules:
2.4 – 5.5Vdc input; 0.75Vdc to 3.63Vdc Output; 6A output current
LINEAGE POWER 13
Feature Descriptions (continued)
Output Voltage Programming
The output voltage of the Austin MicroLynx
TM II 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 30) between the TRIM and GND pins of the
module. Without an external resistor between 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
MicroLynx
TM II module to 1.8 Vdc, Rtrim is calculated is
follows:




−
−
= 5110
7525 . 0 8 . 1
21070
Rtrim
Ω = k Rtrim 004 . 15
V
O
(+)
TRIM
GND
R
trim
LOAD
V
IN
(+)
ON/OFF
Vout
Figure 30. Circuit configuration to program output
voltage using an external resistor.
Table 1 provides Rtrim values required for some common
output voltages.
Table 1
V
O, set
(V) Rtrim (KΩ)
0.7525 Open
1.2 41.973
1.5 23.077
1.8 15.004
2.5 6.947
3.3 3.160
By using a 1% tolerance trim resistor, set point
tolerance of ±2% is achieved as specified in the
electrical specification. 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.
Voltage Margining
Output voltage margining can be implemented in the
Austin MicroLynx
TM II 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 the Output
pin for margining-down. Figure 31 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.
Vo
Austin Lynx or
Lynx II Series
GND
Trim
Q1
Rtrim
Rmargin-up
Q2
Rmargin-down
Figure 31. Circuit Configuration for margining
Output voltage.