32-Tap Digital Potentiometer (DPP™) with Buffered Wiper
The CAT5112 is a single digitally programmable potentiometer (DPP™) designed as a electronic replacement for mechanical potentiometers. Ideal for automated adjustments on high volume production lines, they are also well suited for applications where equipment requiring periodic adjustment is either difficult to access or located in a hazardous or remote environment.
The CAT5112 contains a 32-tap series resistor array connected between two terminals RH and RL. An up/down counter and decoder that are controlled by three input pins, determines which tap is connected to the wiper, RWB. The CAT5112 wiper is buffered by an op amp that operates rail to rail. The wiper setting, stored in non-volatile memory, is not lost when the device is powered down and is automatically recalled when power is returned. The wiper can be adjusted to test new system values without effecting the stored setting. Wiper-control of the CAT5112 is accomplished with three input control pins, CS, U/D, and INC. The INC input increments the wiper in the direction which is determined by the logic state of the U/D input. The CS input is used to select the device and also store the wiper position prior to power down.
The digitally programmable potentiometer can be used as a buffered voltage divider. For applications where the potentiometer is used as a 2-terminal variable resistor, please refer to the CAT5114. The buffered wiper of the CAT5112 is not compatible with that application.