Table of Contents Section 1 – New and Featured Products

®
Signal Conditioning/Calibration and Control Products
X9279 Single Digitally-Controlled (XDCP ) Potentiometer
Product Highlights
• Single Supply
• Low Power
• 256-tap
• 2-Wire Bus
• Non-volatile Digital Potentiometer
Key Features
• 256 Resistor Taps
• 2-Wire Serial Interface for write, read, and transfer operations
of the potentiometer
• Wiper Resistance, 100Ω typical @ 5V
• Endurance: 100,000 Data Changes per Bit per Register
• 14-Lead TSSOP, 16-Lead CSP (Chip Scale Package)
• Low Power CMOS
Benefits
• Digital Programmability
• Set and Forget Calibration
• Reliability
• Dynamic Controls
— Real time calibration
— Adaptive response
• Non-volatile storage and recall of wiper position
• Power On Recall circuits
• General purpose EEPROM
Description
The X9279 integrates a single digitally controlled potentiometer
(XDCP) on a monolithic CMOS integrated circuit.
The digitally controlled potentiometer is implemented using 255
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. The potentiometer has associated
with it a volatile Wiper Counter Register (WCR) and four
non-volatile Data Registers 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 though the switches. Power-up
recalls the contents of the default data register (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.
Pin Configuration
TSSOP
NC
A0
NC
A2
SCL
SDA
V SS
1
2
3
4
5
6
7
14
13
12
X9279 11
10
9
8
V CC
R L
R H
R W
A3
A1
WP
Block Diagram
V CC
R H
2-Wire
Bus
Interface
Address
Data
Status
Bus
Interface &
Control
Write
Read
Transfer
Inc/Dec
Control
Power On Recall
Wiper Counter
Register (WCR)
Data Registers
16 Bytes
wiper
50KΩ and 100KΩ
256-taps
POT
V SS
R W
R L
* for ordering information refer to page 1-45 See Product Family Tree
on page 2-1
1–34
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