Infineon Technologies CYAT81689-100AA77Z

Overview

CYAT81689-100AA77Z from Infineon Technologies is a single-chip capacitive touch controller IC designed for automotive-grade human-machine interface (HMI) applications. It integrates 16 self-capacitive and 16 mutual-capacitive sensing channels, supports up to 10 simultaneous touches, operates over -40°C to +105°C, and features built-in noise immunity for high-voltage automotive environments - deployed in center console touch panels and infotainment control surfaces.

For engineers reviewing the CYAT81689-100AA77Z datasheet, CYAT81689-100AA77Z pinout, CYAT81689-100AA77Z application, or CYAT81689-100AA77Z equivalent, key selection criteria include I²C/SPI interface compatibility, AEC-Q100 Grade 2 qualification, integrated gesture engine, and support for wet-finger and gloved-finger operation under ESD stress.

Technical Context

This device implements a dedicated analog front-end with programmable gain amplifiers and sigma-delta ADCs per channel, enabling sub-1pF capacitance resolution. Its embedded firmware includes real-time baseline tracking, dynamic threshold adjustment, and multi-touch centroid calculation without host CPU intervention.

The controller uses a dual-core architecture: one ARM Cortex-M0+ core handles sensor acquisition and preprocessing, while a second dedicated DSP core executes proprietary touch algorithms including palm rejection, hover detection, and linear interpolation for slider/bar controls.

Key Specifications

Pinout & Package

Package: 64-pin QFN (9 mm × 9 mm, 0.5 mm pitch), thermally enhanced with exposed thermal pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar capacitive touch controller applications.

Compared with STM32T8001TR and MTCH6302-I/SS, CYAT81689-100AA77Z delivers higher channel count, automotive-grade reliability, and integrated algorithmic processing - making it the only option qualified for primary driver-facing touch interfaces requiring functional safety alignment.

Availability

CYAT81689-100AA77Z is available at Aetrix Electronics and suitable for automotive infotainment systems, instrument cluster HMIs, and passenger seat control panels requiring stable component supply across extended production lifecycles.

Supply support for CYAT81689-100AA77Z includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive electronics, and security solutions, with global R&D centers and ISO/TS 16949-certified wafer fabs.

CYAT81689 belongs to Infineon's TrueTouch® automotive touch controller product line, engineered specifically for robust, high-reliability capacitive sensing in harsh vehicular environments with stringent EMC and thermal requirements.

FAQ

What is the maximum trace length supported between CYAT81689-100AA77Z and touch sensor electrodes?

The device supports up to 25 cm of 50 Ω controlled-impedance trace length for mutual-capacitance electrodes and 15 cm for self-capacitance traces, verified per Infineon Application Note AN2294 using FR-4 PCB with 8-mil spacing and ground plane shielding. Longer traces require layout-specific noise margin validation.

Does CYAT81689-100AA77Z support I²C multi-master configurations?

Yes - it implements clock stretching and arbitration logic compliant with I²C Specification Rev. 6, allowing coexistence with other I²C masters on the same bus. The INT pin deasserts only after all pending touch data is read, preventing race conditions during concurrent access.

Can the internal gesture engine be reconfigured for custom gestures?

No - the gesture engine is fixed-function firmware; however, raw capacitance delta data is accessible via SPI register map for host-side algorithm development. Custom gesture logic must run externally, using the device's high-fidelity baseline-subtracted sensor output.

Is the thermal pad on the QFN package required to be soldered to PCB ground?

Yes - the exposed thermal pad must be connected to a minimum 12 mm² copper pour tied to PCB ground plane using ≥4 thermal vias (0.3 mm diameter). This ensures junction temperature remains within spec under continuous 100 Hz scanning at +105°C ambient, per Infineon Package Outline Document PL-64QFN-01.