GE Industrial Solutions 12V Austin MicroLynx 5A - Manual (Page 13)

GE
Data Sheet
12V Austin MicroLynx TM 5A: Non-Isolated DC-DC Power Modules
10Vdc –14Vdc input; 0.75Vdc to 5.5Vdc output; 5A Output Current
May 6, 2013 ©2013 General Electric Company. All rights reserved. Page 13
Feature Descriptions (continued)
Output Voltage Programming
The output voltage of the Austin MicroLynx TM 12V can be
programmed to any voltage from 0.75Vdc to 5.5Vdc by
connecting a resistor (shown as Rtrim in Figure 28) 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




−
−
= 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
MicroLynx TM 12V module to 1.8V, Rtrim is calculated as follows:




−
−
= 1000
7525 . 0 8 . 1
10500
Rtrim
Ω = k Rtrim 024 . 9
V
O
(+)
TRIM
GND
R
trim
LOAD
V
IN
(+)
ON/OFF
Figure 28. Circuit configuration to program output voltage
using an external resistor
Austin MicroLynx TM 12Vdc can also be programmed by applying
a voltage between TRIM and GND pins (Figure 29). The following
equation can be used to determine the value of Vtrim needed to
obtain a desired output voltage Vo:
{ } ( )
7525 . 0 0667 . 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 0667 . 0 7 . 0 ( − × − = Vtrim
V Vtrim 530 . 0 =
V
O
(+)
TRIM
GND
V
t rim
LOAD
V
IN
(+)
ON/OFF
+
-
Figure 29. 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 22.46
1.5 13.05
1.8 9.024
2.5 5.009
3.3 3.122
5.0 1.472
Table 2
V
O, set
(V) Vtrim (V)
0.7525 Open
1.2 0.670
1.5 0.650
1.8 0.630
2.5 0.583
3.3 0.530
5.0 0.4166
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.