AT42QT1085-MUR

Overview

The AT42QT1085 is an eight-key QTouch sensor IC featuring an integrated haptic engine. It supports up to eight touch keys and twelve dedicated GPIO pins, with four additional configurable channels. The device operates on a 2.0 V to 5.5 V supply and communicates via a master/slave SPI interface at speeds up to 750 kHz. It utilizes spread spectrum charge transfer for noise immunity and includes self-calibration, drift compensation, and Adjacent Key Suppression technology. Available in 32-pin 5x5 mm QFN and 7x7 mm TQFP packages.

Feature Summary

• Integrated haptic engine allows feedback effects triggered by touch detection or host control
• Patented Adjacent Key Suppression ensures accurate key detection in close proximity layouts
• Spread spectrum charge transfer modulates acquisition pulses to suppress external noise and RF emissions
• Object-based SPI protocol enables configuration storage in nonvolatile memory

Applications

• Consumer electronics requiring robust capacitive touch interfaces
• Industrial controls needing reliable operation under varying environmental conditions
• Appliances integrating tactile haptic feedback into user interfaces

Procurement Notes

Verify the specific package variant (QFN or TQFP) and ordering suffix against the manufacturer's current datasheet before procurement. Confirm that the component source is authorized to ensure authenticity and compliance with RoHS standards. Check for any recent revisions to the part number that may affect pin compatibility or electrical characteristics.

Selection Notes

Select this component when an application requires multiple independent touch keys combined with haptic feedback capabilities. Ensure the host microcontroller supports the required SPI interface and object protocol. Verify that the panel thickness and electrode materials are compatible with the specified sensing range and sensitivity requirements.

Part Context

This device belongs to the Atmel QTouch family of capacitive sensor controllers. It is designed for applications requiring high reliability and ease of integration without external sampling capacitors. The internal oscillator and advanced signal processing reduce the need for external components, simplifying PCB layout and design time.

Replacement Considerations

Consult Microchip Technology for officially confirmed substitute part numbers. Do not assume cross-compatibility with other QTouch models without verifying pinout, voltage ranges, and protocol support.