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2D Analog Resistive Touch

The AR11xx series is a legacy product suite not recommended for new designs for analog resistive touch.
Introduction to Resistive Touch
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Analog resistive technology is popular because of its:

  • Low-cost sensors
  • Acceptance of finger, glove or stylus-pen inputs
  • Overall ease of manufacturing and integration into applications

Suitable applications for analog resistive include:

  • Mobile phones, industrial automation, retail point-of-sale, gaming/entertainment and automobile navigation systems
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Resistive - How Does it Work?
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An analog resistive touch screen is comprised of two layers, the flex and the stable layer. These layers are coated with a thin electrically conductive coating of Indium Tin Oxide (ITO). These two layers are separated by the spacer layer. When touched, the flex layer comes in contact with the stable layer. The point of contact creates a voltage divider in the X and Y directions. This voltage is then used to find the relative position of the touch activation.
Selecting a Touch Sensor
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Three basic analog resistive sensor constructions:

  • Most cost effective - 4-wire
  • Most durable - 5-wire
  • Most flexible - 8-wire
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AR1000 Series Touch Controllers
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  • Turnkey touch solution
  • Built-in decoding and advanced filtering
  • Controller-driven calibration
  • Low cost with few external components
  • Universal 4-, 5-, and 8-wire support
  • Fast time to market
  • Small footprint
  • Low power
  • SPI, I2C, UART support
  • Developed by touch experts

Resistive Touch Screen Controller Comparison

Microchip BenefitOther Touch Screen Controllers
Touch SolutionTurnkey touch solution - easy integration for an accelerated development cycleIncomplete, require significant engineering to decode, filter and calibrate
Touch CoordinatesDelivers accurate touch coordinates with built-in decoding and advanced filteringNot provided, require customer to become a "touch" expert
Software Driver SupportController-driven callibration - no software drivers needed!Incomplete, require that users write calibration drivers
Design CostLow - including few required componentsHigh - including required components
Sensor SupportUniversal sensor support for all 4-, 5- and 8-wire screens (wide tolerance range)Typically support 4-wire only (tolerance variation may require redesign)
Design Time to MarketFast - no learning curve, works out of the boxSlow - long learning curve, trial and error development
PCB Real EstateSmall footprint, minimal real estateLarge footprint
Touch Expertise15+ years of touch expertiseMinimal
IntegrationEasyDifficult
Driver & Design Support
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For support please contact the Microchip support ticket system. For further support including OS drivers please contact our partner Touch-Base. Touch-Base provides drivers for several OS, driver and design in support.