A
PPLICATION
N
OTES
A V A I L A B L E
AN99 • AN115 • AN120 • AN124 • AN133 • AN134 • AN135
Low Noise/Low Power/SPI Bus
X9410
Dual Digitally Controlled Potentiometer (XDCP
™
)
FEATURES
• Two potentiometers in one package
• SPI serial interface
• Register oriented format
—Direct read/write/transfer wiper positions
—Store as many as four positions per
potentiometer
• Power supplies
—V
CC
= 2.7V to 5.5V
—V+ = 2.7V to 5.5V
—V– = –2.7V to –5.5V
• Low power CMOS
—Standby current < 1µA
• High reliability
—Endurance–100,000 data changes per bit per
register
—Register data retention–100 years
• 8-bytes of nonvolatile EEPROM memory
• 10K
Ω
resistor arrays
• Resolution: 64 taps each pot
• 24-lead TSSOP, 24-lead SOIC and 24-pin plastic
DIP packages
DESCRIPTION
The X9410 integrates two digitally controlled
potentiometers (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 SPI bus
interface. Each potentiometer has associated with it a
volatile Wiper Counter Register (WCR) and 4
nonvolatile Data Registers (DR0:DR3) 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 contents of DR0 to the WCR.
The XDCP can be used as a three-terminal
potentiometer 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
V+
V-
R0 R1
Wiper
Counter
Register
(WCR)
V
H0
/R
H0
HOLD
CS
SCK
SO
SI
A0
A1
WP
R2 R3
V
L0
/R
L0
V
W0
/R
W0
Interface
and
Control
Circuitry
Data
8
Pot 1
R0 R1
Wiper
Counter
Register
(WCR)
V
W1
/R
W1
V
H1
/R
H1
Resistor
Array
Pot1
R2 R3
V
L1
/R
L1
REV 1.1 10/6/00
www.xicor.com
Characteristics subject to change without notice.
1 of 21
XICOR [ XICOR INC. ]
