®
X9221A
64 Taps, 2-Wire Serial Bus
Data Sheet
September 14, 2005
FN8163.1
Dual Digitally Controlled Potentiometer
(XDCP™)
FEATURES
• Two XDCPs in one package
• 2-wire serial interface
• Register oriented format, 8 registers total
—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
• Direct write cell
—Endurance–100,000 writes per bit per register
• Resistor array values
—2kΩ, 10kΩ, 50kΩ
• Resolution: 64 taps each pot
• 20 Ld plastic DIP and 20-lead SOIC packages
• Pb-free plus anneal available (RoHS compliant)
DESCRIPTION
The X9221A integrates two digitally controlled potenti-
ometers (XDCP) on a monolithic CMOS integrated
microcircuit.
The digitally controlled potentiometer is implemented
using 63 resistive elements in a series array. Between
each element are tap points connected to the wiper
terminal through switches. The position of the wiper on
the array is controlled by the user through the 2-wire
bus interface. Each potentiometer has associated with
it a volatile Wiper Counter Register (WCR) and 2 non-
volatile Data Registers (DR0:DR1) that can be directly
written to and read by the user. The contents of the
WCR controls the position of the wiper on the resistor
array through the switches. Power up recalls the con-
tents of DR0 to the WCR.
The XDCP can be used as a three-terminal potentiom-
eter or as a two-terminal variable resistor in a wide
variety of applications including control, parameter
adjustments, and signal processing.
BLOCK DIAGRAM
Pot 0
V
CC
V
SS
R0 R1
Wiper
Counter
Register
(WCR)
V
H0
/R
H0
R2 R3
SCL
SDA
A0
A1
A2
A3
V
L0
/R
L0
V
W0
/R
W0
Interface
and
Control
Circuitry
Data
8
R0 R1
Wiper
Counter
Register
(WCR)
Register
Array
Pot 1
V
H1
/R
H1
R2 R3
V
L1
/R
L1
V
W1
/R
W1
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
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Intersil (and design) is a registered trademark of Intersil Americas Inc.
XDCP is a trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
INTERSIL [ INTERSIL CORPORATION ]
