AD5222

a FEATURES 128-Position, 2-Channel Potentiometer Replacement 10 k⍀ , 50 k⍀ , 100 k⍀, 1 M⍀ Very Low Power: 40 ␮A Max ؎ 2.7 V Dual Supply Operation or 2.7 V to 5.5 V Single Supply Operation Increment/Decrement Count Control APPLICATIONS Stereo Channel Audio Level Control Mechanical Potentiometer Replacement Remote Incremental Adjustment Applications Instrumentation: Gain, Offset Adjustment Programmable Voltage-to-Current Conversion Line Impedance Matching Increment/Decrement Dual Digital Potentiometer AD5222 FUNCTIONAL BLOCK DIAGRAM VDD U/D AD5222 UP/DOWN COUNTER DECODE A1 W1 B1 POR CS MODE DACSEL CLK GND A2 UP/DOWN COUNTER DECODE W2 B2 VSS DAC SELECT AND ENABLE GENERAL DESCRIPTION The AD5222 provides a dual channel, 128-position, digitally controlled variable-resistor (VR) device. This device performs the same electronic adjustment function as a potentiometer or variable resistor. These products were optimized for instrument and test equipment push-button applications. Choices between bandwidth or power dissipation are available as a result of the wide selection of end-to-end terminal resistance values. The AD5222 contains two fixed resistors with wiper contacts that tap the fixed 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 that is equal to the end-to-end resistance divided by the number of positions (e.g., R STEP = 10 ...