I
2
C-Compatible,
256-Position Digital Potentiometers
AD5241/AD5242
FEATURES
256 positions
10 kΩ, 100 kΩ, 1 MΩ
Low temperature coefficient: 30 ppm/°C
Internal power on midscale preset
Single-supply 2.7 V to 5.5 V or dual-supply ±2.7 V for ac or
bipolar operation
2
I C-compatible interface with readback capability
Extra programmable logic outputs
Self-contained shutdown feature
Extended temperature range: −40°C to +105°C
FUNCTIONAL BLOCK DIAGRAM
A
1
W
1
B
1
O
1
O
2
SHDN
V
DD
V
SS
ADDR
DECODE
RDAC
REGISTER 1
REGISTER 2
AD5241
8
PWR-ON
RESET
00926-001
APPLICATIONS
Multimedia, video, and audio
Communications
Mechanical potentiometer replacement
Instrumentation: gain, offset adjustment
Programmable voltage-to-current conversion
Line impedance matching
SDA
SCL
GND
SERIAL INPUT REGISTER
AD0
AD1
Figure 1. AD5241 Functional Block Diagram
A
1
W
1
B
1
A
2
W
2
B
2
O
1
O
2
SHDN
V
DD
V
SS
ADDR
DECODE
1
SDA
SCL
GND
REGISTER
RDAC
REGISTER 1
RDAC
REGISTER 2
AD5242
8
PWR-ON
RESET
00926-002
SERIAL INPUT REGISTER
AD0
AD1
Figure 2. AD5242 Functional Block Diagram
GENERAL DESCRIPTION
The AD5241/AD5242 provide a single-/dual-channel, 256-
position, digitally controlled variable resistor (VR) device. These
devices perform the same electronic adjustment function as a
potentiometer, trimmer, or variable resistor. Each VR offers a
completely programmable value of resistance between the A
terminal and the wiper, or the B terminal and the wiper. For the
AD5242, the fixed A-to-B terminal resistance of 10 kΩ, 100 kΩ,
or 1 MΩ has a 1% channel-to-channel matching tolerance. The
nominal temperature coefficient of both parts is 30 ppm/°C.
Wiper position programming defaults to midscale at system
power on. When powered, the VR wiper position is programmed
by an I
2
C®-compatible, 2-wire serial data interface. Both parts
have two extra programmable logic outputs available that
enable users to drive digital loads, logic gates, LED drivers, and
analog switches in their system.
The AD5241/AD5242 are available in surface-mount, 14-lead
SOIC and 16-lead SOIC packages and, for ultracompact solutions,
14-lead TSSOP and 16-lead TSSOP packages. All parts are
guaranteed to operate over the extended temperature range of
−40°C to +105°C.
Rev. C
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