AT42QT1245-AU

Overview

The AT42QT1245-AU is a digital burst mode charge-transfer touch sensor IC designed for matrix layout controls. It supports up to 24 keys using patented transverse sensing technology with frequency hopping. The device features an SPI interface, self-calibration, auto drift compensation, and Adjacent Key Suppression (AKS). It operates on a +3 V to 5 V supply and is housed in a 32-pin 7 × 7 mm TQFP package. The chip includes FMEA compliant design features and IEC/EN/UL60730 compliance for safety-critical applications.

Feature Summary

• Patented transverse charge-transfer sensing technology with frequency hopping
• Supports mixed key sizes and shapes within a single panel
• Integrated signal processing including self-calibration and noise filtering
• Compliant with FMEA and IEC/EN/UL60730 safety standards

Applications

• Class B and class C safety-critical products
• Domestic appliances requiring FMEA compliance
• Touch panels with plastic, glass, or composite overlays

Procurement Notes

Verify the specific ordering suffix against official Microchip documentation to confirm package type and temperature range. Ensure the component source provides valid traceability and RoHS compliance certificates. Confirm that the datasheet version matches the manufacturing lot requirements for your application.

Selection Notes

Select this model for designs requiring up to 24 matrix keys with high reliability standards. Ensure the host system supports SPI communication and can handle the required initialization sequence. Verify that the PCB layout allows for short traces between the IC and external capacitors to maintain EMC performance.

Part Context

This component belongs to the AT42QT1245 series of QMatrix touch sensors. It is part of Microchip's portfolio of capacitive touch solutions designed for robust operation in electrically noisy environments. The AU suffix indicates the TQFP package variant.

Replacement Considerations

Check for updated revisions of the AT42QT1245 series. Verify pin compatibility if substituting with other QMatrix devices like the AT42QT1481, noting differences in channel count and interface protocols.