Infineon Technologies CY8C20646A-24LQXIT

Overview

CY8C20646A-24LQXIT from Cypress Semiconductor is a programmable 1.8 V CapSense® controller with SmartSense™ auto-tuning, integrating an M8C 8-bit Harvard-architecture CPU (24 MHz max), 16 KB flash, 2 KB SRAM, and dedicated hardware for capacitive sensing of up to 33 buttons or 6 sliders. It supports I²C (up to 400 kHz), SPI (up to 12 MHz), USB 2.0 Full-Speed (12 Mbps), and features dual-mode GPIOs with 25 mA sink capability per pin. Used in touch-enabled human interface modules for industrial HMI and consumer appliances.

For engineers reviewing the CY8C20646A-24LQXIT datasheet, CY8C20646A-24LQXIT pinout, CY8C20646A-24LQXIT application, or CY8C20646A-24LQXIT equivalent, key selection criteria include SmartSense_EMC noise immunity, 28 µA/sensor active current at 125 ms scan interval, USB 2.0 compliance, and QFN-24 package compatibility with 17 sensing inputs.

Technical Context

The device implements a dedicated CapSense analog block with patented CSA_EMC and CSD sensing algorithms, enabling self-calibrating capacitive touch detection without external tuning components. Its SmartSense_EMC algorithm dynamically adjusts sensor thresholds and modulation parameters to maintain stable operation under conducted/radiated EMI stress.

It integrates a 1 V/1.2 V internal analog reference, configurable IDACs, and a global analog bus supporting ganged proximity sensing. The M8C core executes firmware while the hardware CapSense block runs autonomous scanning-reducing CPU load and enabling ultra-low-power wake-up modes (1.1 µA standby, 0.1 µA deep sleep).

Key Specifications

Pinout & Package

Package: 24-pin QFN (4 × 4 mm, 0.5 mm pitch), exposed thermal pad, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY8C20646A-24LQXIT, the CY8C20666A offers higher sensor density and memory but requires QFN-48 layout; MTCH101 provides lower BOM cost for basic I²C touch but lacks USB, programmability, and SmartSense_EMC robustness.

Availability

CY8C20646A-24LQXIT is available at Aetrix Electronics and suitable for industrial HMI, home appliance control panels, and USB HID touch keypads requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for CY8C20646A-24LQXIT 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

Cypress Semiconductor (now part of Infineon Technologies) designs programmable mixed-signal ICs for embedded control, sensing, and connectivity applications, with headquarters in San Jose, CA.

This device belongs to the PSoC® CY8C20xx6A family - purpose-built for low-power, noise-immune capacitive touch interfaces requiring integrated MCU, USB, and auto-tuning capabilities without external components.

FAQ

Does CY8C20646A-24LQXIT require external tuning components for CapSense operation?

No. The device uses patented SmartSense™ and SmartSense_EMC algorithms to automatically calibrate sensor thresholds, IDAC values, and scan parameters in real time. No external resistors, capacitors, or manual tuning steps are needed - enabling consistent performance across manufacturing batches and environmental conditions.

What is the maximum number of capacitive sensors supported in the QFN-24 package?

The CY8C20646A-24LQXIT supports up to 17 capacitive sensing inputs in its 24-pin QFN package. This count accounts for dedicated CapSense pins and excludes pins reserved for USB, I²C, power, and reset functions - confirmed in Cypress Document 001-54459 Rev. *Y, page 11.

Can this device operate from a 3.3 V supply while maintaining full CapSense functionality?

Yes. The device operates across 1.71–5.5 V, and all CapSense features - including SmartSense auto-tuning, USB 2.0 Full-Speed, and I²C - remain fully functional at 3.3 V. The internal LDO and analog reference are designed to maintain accuracy and noise immunity across the entire voltage range.

Is PSoC Designer software still supported for CY8C20646A development?

Yes. Cypress continues to provide PSoC Designer v5.4 as a free, Windows-based IDE for CY8C20xx6A devices. It includes drag-and-drop CapSense user modules, SmartSense configuration tools, USB HID templates, and in-circuit debugging - with full documentation in AN73034 and the Technical Reference Manual.