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
applications requiring a bipolar range for DCP terminals
between V- and VCC.