DESCRIPTION
The X9221A integrates two digitally controlled potentiometers (XDCP) on a monolithic CMOS integrated microcircuit.
The digitally controlled potentiometer is implemented using 63 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. Each potentiometer has associated with it a volatile Wiper Counter Register (WCR) and 2 nonvolatile Data Registers (DR0:DR1) 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 through the switches. Power up recalls the contents of 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.

FEATURES
• Two XDCPs in one package
• 2-wire serial interface
• Register oriented format, 8 registers total
   —Directly write wiper position
   —Read wiper position
   —Store as many as four positions per pot
• Instruction format
   —Quick transfer of register contents to resistor
      array
• Direct write cell
   —Endurance–100,000 writes per bit per register
• Resistor array values
   —2kΩ, 10kΩ, 50kΩ
• Resolution: 64 taps each pot
• 20 Ld plastic DIP and 20-lead SOIC packages
• Pb-free plus anneal available (RoHS compliant)