Data Sheet
Austin MicroLynxTM 12V SMT Non-isolated Power Modules:
10 – 14Vdc input; 0.75Vdc to 5.5Vdc Output; 5A output current
April 1, 2008
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:
VIN(+)
VO(+)
TRIM
ON/OFF
LOAD
10500
⎡
⎤
Rtrim =
−1000 Ω
⎢
⎥
+
-
Vo − 0.7525
trim
V
⎣
⎦
GND
Rtrim is the external resistor in Ω
Vo is the desired output voltage
For example, to program the output voltage of the Austin
MicroLynxTM 12V module to 1.8V, Rtrim is calculated as
follows:
Figure 29. Circuit Configuration for programming
Output voltage using external voltage source
10500
⎡
⎤
Rtrim =
−1000
Table 1 provides Rtrim values for most common
output voltages. Table 2 provides values of
external voltage source, Vtrim for various output
voltage.
⎢
⎣
⎥
⎦
1.8 − 0.7525
Rtrim = 9.024kΩ
Table 1
VIN(+)
VO(+)
VO, set (V)
0.7525
1.2
Rtrim (KΩ)
Open
22.46
ON/OFF
LOAD
TRIM
1.5
13.05
1.8
9.024
R
trim
2.5
5.009
GND
3.3
3.122
5.0
1.472
Figure 28. Circuit configuration to program output
voltage using an external resistor
Table 2
VO, set (V)
0.7525
1.2
Vtrim (V)
Open
Austin MicroLynxTM 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:
0.670
1.5
0.650
1.8
0.630
Vtrim =
(
0.7 − 0.0667×
{
Vo − 0.7525})
2.5
0.583
For example, to program the output voltage of a
MicroLynxTM module to 3.3 Vdc, Vtrim is calculated as
follows:
3.3
0.530
5.0
0.4166
Vtrim = (0.7 − 0.0667×
{
3.3− 0.7525 )
}
Using 1% tolerance trim resistor, set point tolerance of
±2% is achieved as specified in the electrical
Vtrim = 0.530V
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.
LINEAGE POWER
13
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
