X9312 Datasheet, PDF (7/9 Pages) Xicor Inc. – E2POT™ Nonvolatile Digital Potentiometer

X9312
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
V_R
V_R
V_H
V_W/R_W
V_L
Three terminal potentiometer;
variable voltage divider
I
Two terminal variable resistor;
variable current
Basic Circuits
Buffered Reference Voltage
R₁
+V
+5V
V_REF
V_W
+ ^OP-07
–
V_OUT
-5V
V_OUT = V_W/R_W
Cascading Techniques
+V
+V
X
V_W/R_W
+V
V_W/R_W
(a)
(b)
Noninverting Amplifier
+5V
V_S
+ ^LM308A
–
V_O
–5V
R₂
R₁
V_O = (1+R₂/R₁)V_S
Voltage Regulator
Offset Voltage Adjustment
V_IN
317
V_O (REG) _VS
R₁
R₂
R₁
100kΩ
–
I_adj
R₂
10kΩ
+
TL072
V_O (REG) = 1.25V (1+R₂/R₁)+I_adj R₂
10kΩ
10kΩ
+12V
-12V
Comparator with Hysteresis
LT311A
V_S
–
+
V_O
V_O
R₁ R₂
V_UL = {R₁/(R₁+R₂)} V_O(max)
V_LL = {R₁/(R₁+R₂)} V_O(min)
(for additional circuits see AN115)
7
FN8176.0
March 15, 2005