GE Industrial Solutions Austin SuperLynx II 12V SMT - Manual (Page 13)

Data Sheet
October 1, 2009 Austin SuperLynx TM II 12V SMT Non-isolated Power Modules:
8.3 – 14Vdc Input; 0.75Vdc to 5.5Vdc Output;16A output current
LINEAGE POWER 13
Feature Descriptions (continued)
Output Voltage Programming
The output voltage of the Austin SuperLynx TM II 12V can
be programmed to any voltage from 0.75Vdc to 5.5Vdc
by connecting a resistor (shown as Rtrim in Figure 29)
between the Trim and GND pins of the module. Without
an external resistor between the Trim and GND pins, the
output of the module will be 0.7525Vdc. To calculate the
value of the trim resistor, Rtrim for a desired output
voltage, use the following equation:
Ω
⎥⎦
⎤
⎢⎣
⎡
−
−
= 1000
7525 . 0
10500
Vo
Rtrim
Rtrim is the external resistor in Ω
Vo is the desired output voltage
For example, to program the output voltage of the Austin
SuperLynx
TM II module to 1.8V, Rtrim is calculated as
follows:
⎥⎦
⎤
⎢⎣
⎡
−
−
= 1000
75 . 0 8 . 1
10500
Rtrim
Ω = k Rtrim 024 . 9
V
O
(+)
TRIM
GND
R
trim
LOAD
V
IN
(+)
ON/OFF
Figure 29. Circuit configuration to program output
voltage using an external resistor
Table 1 provides Rtrim values for most common
output voltages.
Table 1
V
O, set
(V) Rtrim (KΩ)
0.7525 Open
1.2 22.46
1.5 13.05
1.8 9.024
2.5 5.009
3.3 3.122
5.0 1.472
By using 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.
The amount of power delivered by the module is
defined as the voltage at the output terminals
multiplied by the output current. When using the trim
feature, the output voltage of the module can be
increased, which at the same output current would
increase the power output of the module. Care should
be taken to ensure that the maximum output power of
the module remains at or below the maximum rated
power (P
max
= V
o,set
x I
o,max
).
Voltage Margining
Output voltage margining can be implemented in the
Austin SuperLynx
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 30 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 30. Circuit Configuration for margining
Output voltage.