A
N
D
S
PPLICATION
OTES AND
EVELOPMENT
A V A I L A B L E
AN20 • AN42–48 • AN50–53 • AN73 • XK9241
Terminal Voltage 5V, 64 Taps
X9241
2
Quad E
POT
FEATURES
•
2
Four E
POTs in One Package
•
Two-Wire Serial Interface
•
Register Oriented Format
—Directly Write Wiper Position
—Read Wiper Position
—Store as Many as Four Positions per Pot
•
Instruction Format
—Quick Transfer of Register Contents to
Resistor Array
—Cascade Resistor Arrays
•
Low Power CMOS
•
Direct Write Cell
—Endurance - 100,000 Data Changes per Register
—Register Data Retention - 100 years
•
2
16 Bytes of E
PROM memory
•
3 Resistor Array Values
—2K
to 50K Mask Programmable
—Cascadable For Values of 500 to 200K
•
Resolution: 64 Taps each Pot
•
20-Lead Plastic DIP, 20-Lead TSSOP and
20-Lead SOIC Packages
FUNCTIONAL DIAGRAM
SCL
SDA
INTERFACE
AND
A0
CONTROL
A1
8
CIRCUITRY
A2
A3
DATA
© Xicor, Inc. 1994, 1995, 1996 Patents Pending
3864-2.7 7/1/96 T0/C3/D3 NS
YSTEM
X9241
™
Nonvolatile Digital Potentiometer
DESCRIPTION
The X9241 integrates four nonvolatile E
controlled potentiometers on a monolithic CMOS micro-
circuit.
The X9241 contains four resistor arrays, each com-
posed of 63 resistive elements. Between each element
and at either end are tap points accessible to the wiper
elements. The position of the wiper element on the array
is controlled by the user through the two-wire serial bus
interface.
Each resistor array has associated with it a wiper counter
register and four 8-bit data registers that can be directly
written and read by the user. The contents of the wiper
counter register control the position of the wiper on the
resistor array.
The data register may be read or written by the user. The
contents of the data registers can be transferred to the
wiper counter register to position the wiper. The current
wiper position can be transferred to any one of its
associated data registers.
The arrays may be cascaded to form resistive elements
with 127, 190 or 253 taps.
R0 R1
VH0
WIPER
COUNTER
REGISTER
(WCR)
VL0
R2 R3
VW0
VH1
R0 R1
WIPER
RESISTOR
COUNTER
ARRAY
REGISTER
POT 1
(WCR)
VL1
R2 R3
VW1
1
2
POT digitally
VH2
R0 R1
WIPER
RESISTOR
COUNTER
ARRAY
REGISTER
POT 2
(WCR)
VL2
R2 R3
VW2
VH3
R0 R1
WIPER
RESISTOR
COUNTER
ARRAY
REGISTER
POT 3
(WCR)
VL3
R2 R3
VW3
3864 ILL F07.1
Characteristics subject to change without notice