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ADI AD7889: Low Voltage Controller for Touch Screens

What is it?
The AD7889 is a low voltage 4-wire resistive touch screen controller. The AD7889 works with a single 1.6V to 3.6V supply, and features throughput rates of 105kSPS. The device includes a shutdown mode, which reduces its current consumption to less than 6 µA. The device contains programmable median and an averaging filter to reduce the effects of noise from LCDs and other sources. The combination of these two filters provides a more robust solution, discarding the spurious noise in the signal and keeping only the data of interest. Other user-programmable conversion controls include variable acquisition time, and first conversion delay. Up to 16 averages can be taken per conversion. The AD7889 can run in either slave or stand-alone mode, using an automatic conversion sequencer and timer. The AD7889 has a programmable pin that can operate as either an auxiliary input to the ADC, as a battery monitor, or as a GPIO. There is a programmable interrupt output which can operate in three modes, as a general purpose interrupt to signal when new data is available INT, as an interrupt to indicate when limits are exceeded, or as a pen down interrupt when the screen is touched, PENIRQ. The AD7889 also offers temperature and touch-pressure measurement. Available in a 12-ball, 1.6mm × 2mm WLCSP package with Backside Coating. SPI (AD7889) or I2C (AD7889-1) serial interface options.

How is it used?
* Personal digital assistants
* Smart hand-held devices
* Touch screen monitors
* Point-of-sales terminals
* Medical devices
* Cell phones

What are the key features and customer benefits?
* 4-wire touch screen interface
* 1.6V to 3.6V operation
* Median and averaging filter to reduce noise
* Automatic conversion sequencer and timer
* User-programmable conversion parameters
* Auxiliary analog input/Battery Monitor (0.5 V to 5 V)
* 1 Optional GPIO
* Interrupt outputs (INT,PENIRQ)
* Touch-pressure measurement
* Wake up on touch function
* Shutdown mode: 6 µA maximum
* 12 ball WLCSP 1.6mm × 2mm package with Backside Coat

End Market:
Consumer - Audio; Consumer - Video