AR1011-I/SS

Overview

The Microchip AR1000 Series Resistive Touch Screen Controller is a universal, cost-effective chip designed for high-volume, small form factor touch solutions. The AR1011-I/SS variant specifically supports UART communication at 9600 baud. It features sophisticated proprietary decoding algorithms to process touch data, reducing host processing overhead. Key specifications include a 10-bit resolution, a typical report rate of 140 reports per second, and support for 4-wire, 5-wire, and 8-wire analog resistive sensors. The device operates within a 2.5V to 5.0V supply range and includes built-in drift compensation and power-saving sleep modes.

Feature Summary

• Supports 4-Wire, 5-Wire, and 8-Wire analog resistive touch sensors with lead-to-lead resistance of 50-2,000 Ω.
• Provides 10-bit maximum resolution with a typical touch coordinate report rate of 140 reports per second.
• Includes 128 Bytes of user EEPROM for storing calibration data independently of the host system.
• Features built-in drift compensation algorithms and power-saving sleep mode with standby current as low as 40 µA (typical at 2.5V).

Applications

• Mobile communication devices
• Personal Digital Assistants (PDA)
• Global Positioning Systems (GPS)
• Touch Screen Monitors
• Point of Sale Terminals

Procurement Notes

Verify that the specific part number AR1011-I/SS corresponds to the UART interface variant, as other suffixes in the AR1000 series may support SPI or I2C protocols. Confirm the package type is SSOP-20 and the temperature grade is Industrial (-40°C to +85°C). Ensure the ordering suffix matches the required communication protocol for the target application design.

Selection Notes

Select the AR1011-I/SS when UART communication at 9600 baud is required for the host interface. For SPI or I2C interfaces, consider the AR1021 variants instead. Ensure the touch sensor used has a time constant of 500 µs or less and layer-to-layer capacitance between 0-0.5 µF. Verify that the host system can handle the 17 mA typical operating current during touch events.

Part Context

The AR1011-I/SS belongs to the Microchip mTouch AR1000 Series of Resistive Touch Screen Controllers. This series is designed to offload touch processing from the main host processor by handling decoding, filtering, and calibration internally. The 'I' suffix indicates an industrial temperature range, and '/SS' denotes the SSOP-20 package.

Replacement Considerations

For SPI or I2C interfaces, the AR1021T-I/SS or AR1021T-I/ML are functional substitutes within the same family but use different communication protocols. Direct replacement requires verifying that the host controller supports the alternative interface (SPI/I2C) if switching from the UART-based AR1011.