AT42QT1245-AUR

Overview

The AT42QT1245-AUR is a 24-key capacitive touch sensor IC from Microchip Technology, packaged in a 32-pin TQFP (7x7 mm) with an AUR suffix indicating tape and reel packaging. It operates on a +3 V to 5 V supply and communicates via an SPI interface. The device supports up to 24 keys using patented charge-transfer technology with frequency hopping. It features self-calibration, auto drift compensation, noise filtering, and Adjacent Key Suppression®. Designed for FMEA and IEC/EN/UL60730 compliance, it detects key failures and includes UL approval and VDE compliance for safety-critical applications.

Feature Summary

• Supports up to 24 keys using patented transverse charge-transfer sensing technology with frequency hopping to mitigate environmental noise.
• Incorporates comprehensive signal processing including self-calibration, auto drift compensation, noise filtering, and Adjacent Key Suppression®.
• Complies with FMEA, IEC/EN/UL60730 standards, and holds UL approval and VDE compliance for use in class B and C safety-critical products.
• Features integrated failure detection mechanisms that identify and report key failures, X/Y line shorts, and capacitor faults.

Applications

• Safety-critical control panels requiring FMEA and IEC/EN/UL60730 compliance
• Appliances with mixed key sizes and shapes on plastic or glass panels up to 50 mm thick
• Industrial interfaces needing robust noise immunity through frequency hopping and Adjacent Key Suppression

Procurement Notes

Verify the AUR suffix confirms tape and reel packaging when ordering. Confirm the specific package variant matches your PCB footprint requirements. Ensure power supply stability as the device uses VDD as an analog reference. Check RoHS3 compliance status if required by your manufacturing process. Validate that the host system can handle the SPI slave interface timing constraints.

Selection Notes

Select this component for designs requiring up to 24 independent touch inputs with high reliability standards. Ensure the application panel material allows for the specified electrode coupling. Verify that the host microcontroller supports the required SPI communication protocol. Consider the thermal operating range of -40°C to 105°C for environmental suitability. Evaluate the need for FMEA compliance to determine if additional external components are necessary.

Part Context

The AT42QT1245 belongs to the QMatrix family of touch sensors designed for matrix layouts. It utilizes transverse charge-transfer technology to enable flexible electrode designs. The device integrates all necessary signal processing for stable operation under varying conditions. It is suitable for single-sided PCB constructions to minimize cost. The AUR suffix specifically denotes the tape and reel packaging format for automated assembly.

Replacement Considerations

Public confirmed substitute part numbers: None identified in verified documentation.