X93155 Datasheet, PDF (6/8 Pages) Intersil Corporation – Digitally Controlled Potentiometer (XDCP)

X93155
changed by the system or until a power-up/down cycle
recalled the previously stored data. In order to recall the
stored position of the wiper on power-up, the CS pin must be
held HIGH.
This procedure allows the system to always power-up to a
preset value stored in nonvolatile memory; then during
system operation minor adjustments could be made. The
adjustments might be based on user preference, system
parameter changes due to temperature drift, or other system
trim requirements.
The state of U/D may be changed while CS remains LOW.
This allows the host system to enable the device and then
move the wiper up and down until the proper trim is attained.
Mode Selection
CS INC U/D
MODE
L
H Wiper Up
L
L Wiper Down
H
X Store Wiper Position
H
X
X Standby Current
L
X No Store, Return to Standby
L
H Wiper Up (not recommended)
L
L Wiper Down (not recommended)
Symbol Table
WAVEFORM INPUTS
OUTPUTS
Must be
steady
Will be
steady
May change
from Low to
High
May change
from High to
Low
Don’t Care:
Changes
Allowed
N/A
Will change
from Low to
High
Will change
from High to
Low
Changing:
State Not
Known
Center Line
is High
Impedance
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.
I
V_R
Two terminal variable resistor.
Low Voltage High Impedance Instrumentation Amplifier
5V
10K
+
+
10K
U1A
-
50K
V_IN
X93155 (R_TOTAL)
50K
-
10K
10K
-
U1B
+
50K
-
U1C
+
V_OUT
GAIN =
50K
10K
( 1+
50K ₎
R_TOTAL
U1 = LT1467
50K
6
FN8181.1
September 26, 2005