2
FN8188.2
February 1, 2008
Block Diagram
5-BIT
UP/DOWN
COUNTER
5-BIT
NONVOLATILE
MEMORY
STORE AND
RECALL
CONTROL
CIRCUITRY
ONE
OF
DECODER
RESISTOR
ARRAY
RH1
U/D1
INC1
CS1
TRANSFER
GATES
THIRTY
VCC
VSS
RL1
GENERAL DESCRIPTION
DETAILED SINGLE POTENTIOMETER DESCRIPTION
0
1
2
28
29
30
31
TWO
CONTROL
AND
MEMORY
UP/DOWN
(U/D1 AND U/D2)
INCREMENT
(INC1 AND INC2)
DEVICE SELECT
(CS1 AND CS2)
VCC (SUPPLY VOLTAGE)
VSS (GROUND)
RH1
RL1
30k
RH2
RL2
RW
RW1
RW2
Pin Descriptions
TSSOP
SYMBOL
BRIEF DESCRIPTION
1RW1
RW1. The RW1 pin of the X93256 is the wiper terminal of the first potentiometer, which is equivalent to the movable
terminal of a mechanical potentiometer.
2RL1
RL1. The RH1 and RL1 pins of the X93256 are equivalent to the fixed terminals of a mechanical potentiometer. The
minimum voltage is VSS and the maximum is VCC. The terminology of RH1 and RL1 references the relative position of
the terminal in relation to wiper movement direction selected by the U/D input.
3CS1
Chip Select 1 (CS1). The first potentiometer is selected when the CS1 input is LOW. The current counter value is stored
in nonvolatile memory when CS1 is returned HIGH while the INC1 input is also HIGH. After the store operation is
complete, the first potentiometer of the X93256 will be placed in the low power standby mode until the first potentiometer
is selected once again.
4INC2
Increment 2 (INC2). The INC2 input is negative-edge triggered. Toggling INC2 will move the wiper of the second
potentiometer and either increment or decrement the counter in the direction indicated by the logic level on the U/D2
input.
5U/D2
Up/Down 2 (U/D2). The U/D2 input controls the direction of the second potentiometer wiper movement and whether the
counter for the second potentiometer is incremented or decremented.
6RH2
RH2. The RH2 and RL2 pins of the X93256 are equivalent to the fixed terminals of a mechanical potentiometer. The
minimum voltage is VSS and the maximum is VCC. The terminology of RH2 and RL2 references the relative position of
the wiper terminal for the second potentiometer in relation to the wiper movement direction selected by the U/D2 input.
7VSS
Ground.
8RW2
RW2. The RW2 pin of the X93256 is the wiper terminal of the second potentiometer, which is equivalent to the movable
terminal of a mechanical potentiometer.
9RL2
RL2. The RH2 and RL2 pins of the X93256 are equivalent to the fixed terminals of a mechanical potentiometer. The
minimum voltage is VSS and the maximum is VCC. The terminology of RH2 and RL2 references the relative position of
the wiper terminal for the second potentiometer in relation to the wiper movement direction selected by the U/D2 input.
10
CS2
Chip Select 2 (CS2). The second potentiometer is selected when the CS2 input is LOW. The current counter value is
stored in nonvolatile memory when CS2 is returned HIGH while the INC2 input is also HIGH. After the store operation is
complete, the second potentiometer of the X93256 will be placed in the low power standby mode until the second
potentiometer is selected once again.
11
VCC
Supply Voltage.
12
INC1
Increment 1(INC1). The INC1 input is negative-edge triggered. Toggling INC1 will move the wiper of the first
potentiometer and either increment or decrement the counter in the direction indicated by the logic level on the U/D1
input.
13
U/D1
Up/Down 1 (U/D1). The U/D1 input controls the direction of the first potentiometer wiper movement and whether the
counter for the first potentiometer is incremented or decremented.
14
RH1
RH1. The RH1 and RL1 pins of the X93256 are equivalent to the fixed terminals of a mechanical potentiometer. The
minimum voltage is VSS and the maximum is VCC. The terminology of RH1 and RL1 references the relative position of
the wiper terminal for the first potentiometer in relation to the wiper movement direction selected by the U/D1 input.
X93256