Digital Potentiometer 256POS 50KOhm Quad 20-Pin QFN EP

The ISL22444 integrates four digitally controlled potentiometers (DCP), control logic and non-volatile memory on a monolithic CMOS integrated circuit. The digitally controlled potentiometers are implemented with a combination of resistor elements and CMOS switches. The wipers position is controlled by the user through the SPI serial interface. Each potentiometer has an associated volatile Wiper Register (WRi) and a non-volatile Initial Value Register (IVRi) that can be directly written to and read by the user. The contents of the WRi control the position of the wiper. At power-up the device recalls the contents of the DCP’s IVRi to the corresponding WRi. The ISL22444 also has 11 General Purpose non-volatile registers that can be used as storage of lookup table for multiple wiper position or any other valuable information.The ISL22444 features a dual supply that is beneficial for applicationsrequiring a bipolar range for DCP terminals between V- and VCC. Each DCP can be used as three-terminal potentiometer or as two-terminal variable resistor in a wide variety of applications including control, parameter adjustments, and signal processing.

• Four potentiometers in one package
• 256 resistor taps
• SPI serial interface with write/read capability
• Daisy Chain Configuration
• Shutdown mode
• Non-volatile EEPROM storage of wiper position
• 11 General Purpose non-volatile registers
• High reliability
  • Endurance: 1,000,000 data changes per bit per register
  • Register data retention: 50 years @ T =55°C
• Wiper resistance: 70? typical @ 1mA
• Standby current