I2C® Compatible
256-Position Digital Potentiometers
a
AD5241/AD5242
FUNCTIONAL BLOCK DIAGRAM
FEATURES
256 Positions
10 kꢀ, 100 kꢀ, 1 Mꢀ
A
W
B
1
O
O
2
1
1
1
Low Tempco 30 ppm/ꢁC
Internal Power ON Midscale Preset
Single-Supply 2.7 V to 5.5 V or
Dual-Supply ꢂ2.7 V for AC or Bipolar Operation
I2C Compatible Interface with Readback Capability
Extra Programmable Logic Outputs
Self-Contained Shutdown Feature
Extended Temperature Range –40ꢁC to +105ꢁC
SHDN
AD5241
V
DD
RDAC
REGISTER 1
REGISTER 2
V
SS
ADDR
DECODE
8
APPLICATIONS
Multimedia, Video, and Audio
Communications
SDA
SCL
GND
PWR-ON
RESET
SERIAL INPUT REGISTER
Mechanical Potentiometer Replacement
Instrumentation: Gain, Offset Adjustment
Programmable Voltage-to-Current Conversion
Line Impedance Matching
AD1
AD0
A
1
W
B
1
A
W
B
O
1
O
2
1
2
2 2
REGISTER
SHDN
GENERAL DESCRIPTION
V
DD
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 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.
RDAC
REGISTER 1
RDAC
REGISTER 2
V
SS
ADDR
DECODE
AD5242
8
1
SDA
SCL
GND
PWR-ON
RESET
SERIAL INPUT REGISTER
AD1
AD0
Wiper position programming defaults to midscale at system
power ON. Once powered, the VR wiper position is programmed
by an I2C compatible 2-wire serial data interface. Both parts
have available two extra programmable logic outputs 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 (SOIC-14/-
16) packages and, for ultracompact solutions, TSSOP-14/-16
packages. All parts are guaranteed to operate over the
extended temperature range of –40°C to +105°C. For 3-wire,
SPI compatible interface applications, please refer to AD5200,
AD5201, AD5203, AD5204, AD5206, AD5231*, AD5232*,
AD5235*, AD7376, AD8400, AD8402, and AD8403 products.
*Nonvolatile digital potentiometer
I2C is a registered trademark of Philips Corporation.
REV. B
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reliable. However, no responsibility is assumed by Analog Devices for its
use, norforanyinfringementsofpatentsorotherrightsofthirdpartiesthat
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
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© Analog Devices, Inc., 2002