Burr-Brown Corporation announced the ADS7845, the industry's only complete, single-chip, 12-bit analog-to-digital converter (ADC) solution available for 5-wire resistive touch screen applications that has all the "touch screen interface" featuresýincluding driversýon one chip.

The ADS7845 offers improved performance, lower power consumption, and lower cost over all existing solutions. Its features make it ideal for battery operated and portable applications such as PDA (Personal Data Assistant) calculators, touch screen monitors, touch screen white boards, and other applications that utilize a resistive touch screen element.

In these applications, the ADS7845 measures a change in resistance as the screen is touched. The resistive change is then used to determine the exact location of contact upon a touch screen device.

"The ADS7845 is an obvious solution for customers struggling to build their own controller with a 12-bit ADC, drivers, control logic, and the screen 'turn-on' function," said Skip Osgood, product marketing manager at Burr-Brown. "In addition to simplifying circuit complexity, this device reduces error and provides higher resolution, thus enhancing touch screen reading accuracy."

Osgood added: "As a companion component to the previously introduced ADS7843 4-wire touch screen controller, the ADS7845 strengthens our leadership in complete, single-chip touch screen solutions."

There have been spirited design attempts at any number of home-built front-ends for touch screen controllers out there and this part will, hopefully, remove a lot of late night headaches for those designers and give them good reasons to use a single part. The use of a 12-bit ADC will allow much finer determinations of position on the surface of the screen and the 5-wire interface covers the latest screen developments. The higher resolution will be particularly noticed on the larger screens such as touch screen white boards. The power consumption of 0.6 mW is extremely low at the usefully-low 2.7-V supply. Together with the previously-announced 4-wire controller, the ADS7843, these parts will be high-volume sellers.