Feature descriptions – GE Industrial Solutions Austin Microlynx SIP User Manual
Page 13
Data Sheet
July 2, 2010
Austin MicroLynx
TM
SIP Non-isolated Power Modules:
3 – 5.5Vdc input; 0.75Vdc to 3.63Vdc Output; 5A output current
LINEAGE
POWER
13
Feature Descriptions
(continued)
Output Voltage Programming
The output voltage of the Austin MicroLynx
TM
can be
programmed to any voltage from 0.75Vdc to 3.63Vdc by
connecting a resistor (shown as Rtrim in Figure 29)
between Trim and GND pins of the module. Without an
external resistor between Trim and GND pins, the output
of the module will be 0.7525Vdc. To calculate the value
of the trim resistor, Rtrim for a desired output voltage, use
the following equation:
Ω
−
−
=
5110
7525
.
0
21070
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
MicroLynx
TM
module to 1.8V, Rtrim is calculated as
follows:
−
−
=
5110
7525
.
0
8
.
1
21070
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
Austin MicroLynx
TM
can also be programmed by applying
a voltage between TRIM and GND pins (Figure 30). The
following equation can be used to determine the value of
Vtrim
needed to obtain a desired output voltage Vo:
{
}
(
)
7525
.
0
1698
.
0
7
.
0
−
×
−
=
Vo
Vtrim
For example, to program the output voltage of a
MicroLynx
TM
module to 3.3 Vdc, Vtrim is calculated as
follows:
{
}
)
7525
.
0
3
.
3
1698
.
0
7
.
0
(
−
×
−
=
Vtrim
V
Vtrim
2670
.
0
=
V
O
(+)
TRIM
GND
V
t
rim
LOAD
V
IN
(+)
ON/OFF
+
-
Figure 30. Circuit Configuration for programming
Output voltage using external voltage source
Table 1 provides Rtrim values for most common
output voltages. Table 2 provides values of
external voltage source, Vtrim for various output
voltage.
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
Table 2
V
O, set
(V)
Vtrim
(V)
0.7525 Open
1.2 0.6240
1.5 0.5731
1.8 0.5221
2.5 0.4033
3.3 0.2670
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.