The ISL23428 is a volatile, low-voltage, low-noise, low-power, 128-tap, dual digital control potentiometer (DCP) with an SPI bus interface. It integrates two DCP cores, wiper switches, and control logic on a single chip CMOS integrated circuit. Each digital control potentiometer is realized by a combination of resistance elements and CMOS switches.
The location of the wiper is controlled by the user through the SPI bus interface. Each potentiometer has an associated volatile wiper register (WRi, i = 0,1) that can be written and read directly by the user. The content of WRi controls the position of the wiper. When powered on, the wipers of each DCP will always start at medium scale (64 gears).
Block Diagram
The ISL23428's low voltage, low power consumption and small packaging make it ideal for battery-powered devices. In addition, the ISL23428 has a VLOGIC pin that allows for bus operation as low as 1.2V, independent of VCC values. This allows low logic levels to be connected directly to ISL23428 without going through a voltage level shifter. DCP can be used as a three-terminal potentiometer or a two-end variable resistor for a wide range of applications, including control, parameter adjustment and signal processing.
