8

FN8185.2

September 26, 2006

APPLICATIONS INFORMATION

Electronic digitally controlled (XDCP) potentiometers provide three powerful application advantages; (1) the variability

and reliability of a solid-state potentiometer, (2) the flexibility of computer-based digital controls, and (3) the retentivity

of nonvolatile memory used for the storage of multiple potentiometer settings or data.

Basic Configurations of Electronic Potentiometers

Basic Circuits

I

Three terminal potentiometer;

variable voltage divider

Two terminal variable resistor;

variable current

Cascading Techniques

Buffered Reference Voltage

–

+

+5V

+V

LMC7101

+V

+V

+V

X

(a)

(b)

Single Supply Inverting Amplifier

Voltage Regulator

317

Offset Voltage Adjustment

+

–

100k

Ω

10k

Ω

10k

Ω

10k

Ω

+15V

LMC7101

Comparator with Hysteresis

+

–

LMC7101

+

–

LT311A

(for additional circuits see AN115)

+12V

+8V

100K

100K

+10V

X9319