The X9221A is a digitally controlled potentiometer produced by Texas Instruments. It has 64 taps, 2-wire serial bus, 8 registers in total, can 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 of 100,000 writes per bit per register, resistor array values of 2kΩ, 10kΩ, 50kΩ, resolution of 64 taps each pot, 20 Ld plastic DIP and 20 Ld SOIC packages, lead-free plus anneal available (RoHS compliant).
The X9221A is a highly integrated dual digitally controlled potentiometer (XDCP) that combines two 64‑tap resistor arrays with a 2‑wire serial interface. It offers register‑oriented control with eight registers per device, allowing direct read/write of wiper positions and storage of up to four positions per pot.
The document includes ordering information, pin descriptions, detailed operation principles, instruction set, and package dimensions for both SOIC and PDIP variants. It also outlines the serial communication protocol, device addressing, and programming procedures such as ACK polling and increment/decrement commands.
| Number of XDCPs | 2 |
|---|---|
| Serial Interface | 2‑wire (SCL, SDA) |
| Resolution per Potentiometer | 64 taps |
| Device Address Identifier | 0101b |
It uses a 2‑wire serial interface with SCL (Serial Clock) and SDA (Serial Data) pins.
Each potentiometer provides 64 taps.
The device address identifier is fixed as the binary pattern 0101.