Datasheet

LM3420
www.ti.com SNVS116D –MAY 1998–REVISED MAY 2013
Figure 28. Normalized Temperature Drift with Output Externally Trimmed
Decreasing V
REG
Figure 29. Increasing V
REG
Figure 30. Changing V
REG
Formulas for selecting trim resistor values are shown below, based on the percent of increase (%incr) or percent
of decrease (%decr) of the output voltage from the nominal voltage.
For LM3420-4.2
R
increase
= 22x10
5
/%incr (2)
R
decrease
= (53x10
5
/%decr) − 75x10
3
(3)
For LM3420-8.2
R
increase
= 26x10
5
/%incr (4)
R
decrease
= (150x10
5
/%decr) − 176x10
3
(5)
For LM3420-8.4
R
increase
= 26x10
5
/%incr (6)
R
decrease
= (154x10
5
/%decr) − 181x10
3
(7)
For LM3420-12.6
R
increase
= 28x10
5
/%incr (8)
R
decrease
= (259x10
5
/%decr) − 287x10
3
(9)
For LM3420-16.8
R
increase
= 29x10
5
/%incr (10)
R
decrease
= (364x10
5
/%decr) − 392x10
3
(11)
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