Rainbow Electronics MAX5484 - Manual (Page 18)

MAX5481–MAX5484
10-Bit, Nonvolatile, Linear-Taper Digital
Potentiometers
18 ______________________________________________________________________________________
Programmable Filter
Figure 12 shows the configuration for a 1st-order pro-
grammable filter using two variable resistors. Adjust R2
for the gain and adjust R3 for the cutoff frequency. Use
the following equations to estimate the gain (G) and the
3dB cutoff frequency (f
C ):
G
R
R
f
R C
C
= + ⎛
⎝⎜
⎞
⎠⎟
=
Ч Ч
1
1
2
1
2 3
π
V OUT
30V
5V
W
L
MAX5483
MAX5484
MAX480
Figure 10. Positive LCD Bias Control Using a Variable Resistor
V
OUT
V
IN
R1
R2
R3
C
W
L
W
L
MAX5483
MAX5484
MAX5483
MAX5484
Figure 12. Programmable Filter
V
OUT
W
L
MAX5481
MAX5482
MAX5483
MAX5484
V REF
W
H
L
V IN
Figure 11. Programmable Gain/Offset Adjustment
V OUT
30V
5V
W
H
L
MAX5481
MAX5482
MAX480
Figure 9. Positive LCD Bias Control Using a Voltage-Divider