X9420 Datasheet, PDF (1/20 Pages) Xicor Inc. – Single Digitally Controlled (XDCP) Potentiometer

APPLICATION NOTES
AVAILABLE
AN99 • AN115 • AN120 • AN124 • AN133 • AN134 • AN135
Low Noise/Low Power/SPI Bus
X9420
Single Digitally Controlled (XDCP) Potentiometer
FEATURES
• Solid-State Potentiometer
• 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
• 10KΩ or 2.5KΩ resistor arrays
• Resolution: 64 taps each pot
• 14-lead TSSOP, 16-lead SOIC, and 16-pin plastic
DIP packages
DESCRIPTION
The X9420 integrates a single 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. The 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
HOLD
CS
SCK
S0
SI
A0
Interface
and
Control
Circuitry
8
Data
R0 R1
R2 R3
Wiper
Counter
Register
(WCR)
V_H/R_H
V_L/R_L
V_W/R_W
REV 1.1.6 7/30/02
www.xicor.com
Characteristics subject to change without notice. 1 of 20