Analog Devices Inc. AD5220BRMZ100

Description
The AD5220 is a single-channel, 128-position digitally controlled variable resistor (VR) device. It functions as an electronic replacement for potentiometers or variable resistors. The device features a fixed resistor with a wiper contact that taps the resistor value at a point determined by a digitally controlled UP/DOWN counter. The resistance between the wiper and either end point of the fixed resistor provides a constant resistance step size. The variable resistor offers adjustable resistance values between the A terminal and the wiper, or the B terminal and the wiper. The fixed A-to-B terminal resistance is available in 10 kΩ, 50 kΩ, or 100 kΩ with a nominal temperature coefficient of 800 ppm/°C.
The AD5220 is controlled by chip select (CS), count clock (CLK), and up/down (U/D) direction control inputs. These inputs set the variable resistor position and can be generated using mechanical or push-button switches. External debounce circuitry is required for the negative-edge sensitive CLK pin.

Features
128-position potentiometer replacement
10 kΩ, 50 kΩ, 100 kΩ resistance options
Very low power consumption: 40 μA max
Increment/decrement count control

Applications
Mechanical potentiometer replacement
Remote incremental adjustment applications
Instrumentation: gain, offset adjustment
Programmable voltage-to-current conversion
Programmable filters, delays, time constants
Line impedance matching
Power supply adjustment