AT42QT1245-MU

Overview

The AT42QT1245-MU is a 24-key QMatrix capacitive touch sensor IC manufactured by Microchip Technology. It utilizes patented transverse charge-transfer technology with frequency hopping for stable sensing. The device supports up to 24 keys in a matrix layout and features an SPI interface for data extraction and configuration. It operates on a power supply of +3 V to 5 V and is housed in a 32-pin, 7 × 7 mm TQFP package. Key signal processing functions include self-calibration, auto drift compensation, noise filtering, and Adjacent Key Suppression (AKS).

Feature Summary

• Supports up to 24 keys using a two-part electrode design compatible with various panel materials.
• Integrates FMEA compliant design features and IEC/EN/UL60730 safety compliance for critical products.
• Includes detection integrators and self-test mechanisms to identify key failures and short circuits.

Applications

• Class B and Class C safety-critical products requiring UL approval and VDE compliance.
• Domestic appliances and control boards needing robust FMEA testing capabilities.
• Touch interfaces utilizing plastic, glass, or composite panels up to specified thicknesses.

Procurement Notes

Verify the specific ordering suffix against official documentation to confirm package type and environmental compliance status. Ensure the component matches the required pinout and interface specifications for your host system integration. Cross-reference the manufacturer part number with authorized distributors to confirm authenticity and current production status before finalizing procurement orders.

Selection Notes

Select this component when a high channel count matrix touch solution is required with integrated safety compliance features. The SPI interface allows for flexible communication with host microcontrollers. Consider the physical constraints of the 32-pin TQFP package and ensure adequate PCB space for the necessary external matrix resistors and sample capacitors near the chip body.

Part Context

This part belongs to the AT42QT1245 series of QMatrix touch sensors designed for complex keypad layouts. It distinguishes itself from single-channel or low-channel devices by supporting up to 24 keys in a matrix configuration. The series emphasizes safety-critical applications through built-in FMEA and IEC/EN/UL60730 compliance features, making it suitable for demanding industrial and consumer environments.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided source material. Consult Microchip Technology's official cross-reference tools or datasheet revision notes for potential alternatives or updated versions of the AT42QT1245 series.