The X9221A integrates two digitally controlled potentiometers (XDCPS) on a single chip CMOS integrated microcircuit. The digital control potentiometer is realized by a series array of 63 resistance elements. Between each element are contacts connected to the wiper terminal by a switch.
Pin arrangement
The position of the wiper on the array is controlled by the user through a 2-wire bus interface. Each potentiometer is associated with a volatile wiper counter register (WCR) and two non-volatile data registers (DR0:DR1) that can be written and read directly by the user.
Block diagram
The contents of the WCR control the wiper position on the resistance array via a switch. Power up recalls the contents of DR0 to WCR. XDCP can be used as a three-terminal potentiometer or a two-end variable resistor for a variety of applications including control, parameter adjustment, and signal processing.
Detailed potentiometer block diagram
Features
● Two XDCPs in one package
● 2-wire serial interface
● Register oriented format, 8 registers total
- Directly write wiper position
- Read the 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, 50 kΩ
● Resolution: 64 taps each pot
● 20 Ld plastic DIP and 20 Ld SOIC packages
● Pb-free plus anneal available (RoHS compliant)