X9C303
PIN DESCRIPTIONS
V
H
and V
L
The high (V
H
) and low (V
L
) terminals of the device are
equivalent to the fixed terminals of a mechanical
potentiometer. The minimum voltage is –5V and the
maximum is +5V. It should be noted that the terminol-
ogy of V
L
and V
H
references the relative position of the
terminal in relation to wiper movement direction
selected by the U/D input and not the voltage potential
on the terminal.
V
W
V
W
is the wiper terminal, equivalent to the movable ter-
minal of a mechanical potentiometer. The position of
the wiper within the array is determined by the control
inputs. The wiper terminal series resistance is typically
40
Ω
.
Up/Down (U/D)
The U/D input controls the direction of the wiper move-
ment and whether the counter is incriminated or decre-
mented.
Increment (INC)
The INC input is negative-edge triggered. Toggling INC
will move the wiper and either increment or decrement
the counter in the direction indicated by the logic level
on the U/D input.
Chip Select (CS)
The device is selected when the CS input is LOW. The
current counter value is stored in nonvolatile memory
when CS is returned HIGH while the INC input is also
HIGH. After the store operation is complete the device
will be placed in the low power standby mode until the
device is selected once again.
PIN CONFIGURATION
DIP/SOIC/(TSSOP)
(CS) INC
(V
CC
) U/D
(INC) V
H
(U/D) V
SS
1
2
3
4
X9C303
8
7
6
5
V
CC
(V
L
)
CS (V
W
)
V
L
(V
SS
)
V
W
(V
H
)
V
L
R1 + R2 + . . . + Ri
VW
G i = 20Log ------------------------------------------------ = ---------
(
V L = 0V
)
-
R TOTAL
VS
R 1 + R 2 + . . . + R 99 @ 33KΩ = R TOTAL
(Refer Test Circuit 1)
PIN NAMES
Symbol
V
H
V
W
V
L
V
SS
V
CC
U/D
INC
CS
NC
Description
High Terminal (Potentiometer)
Wiper Terminal (Potentiometer)
Low Terminal (Potentiometer)
Ground
Supply Voltage
Up/Down Control Input
Increment Control Input
Chip Select Control Input
No Connection
POTENTIOMETER RELATIONSHIPS
S100
V
H
(V
S
)
S99
S98
V
W
R99
R98
S3
R2
R1
S2
S1
REV 1.1 4/27/01
www.xicor.com
Characteristics subject to change without notice.
2 of 10
XICOR [ XICOR INC. ]
