Infineon Technologies CY8C20637-24LQXIT

Overview

CY8C20637-24LQXIT from Cypress Semiconductor is a 1.8 V CapSense® controller IC with SmartSense™ auto-tuning, implementing a dedicated capacitive sensing block for up to 31 buttons, 6 sliders, and proximity sensing. It integrates an M8C 8-bit Harvard-architecture CPU (24 MHz max), 8 KB flash, 1 KB SRAM, and supports 48-pin QFN packaging. Its CSD PLUS™ sigma-delta sensing algorithm delivers 0.1 pF sensitivity and operates across –40 °C to +85 °C for industrial human-interface applications.

For engineers reviewing the CY8C20637-24LQXIT datasheet, CY8C20637-24LQXIT pinout, CY8C20637-24LQXIT application, or CY8C20637-24LQXIT equivalent, key selection criteria include its integrated SmartSense_EMC_PLUS runtime auto-tuning, driven-shield support on five GPIOs, I²C slave (up to 400 kHz), low-power deep-sleep mode (0.1 µA), and configurable analog mux bus for ganged proximity sensing.

Technical Context

The device implements a dedicated CapSense PSoC block with Capacitive Sigma Delta PLUS (CSD PLUS™) sensing architecture, enabling hardware-accelerated scanning without CPU intervention. It uses an internal 1.0 V or 1.2 V analog reference and supports overlay thicknesses up to 15 mm (glass) or 5 mm (plastic).

SmartSense_EMC_PLUS operates continuously in run time to adjust sensor parameters-including IDAC current, scan resolution, and noise filters-compensating for environmental drift and manufacturing variation. The analog global bus connects all GPIOs to the CapSense comparator and IDAC, enabling flexible sensor routing and ganged proximity configurations.

Key Specifications

Pinout & Package

Package: 48-pin QFN (7 mm × 7 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 sensing controller applications.

Compared with MTCH101-I/ST and STM32F072CBT6, CY8C20637-24LQXIT provides integrated hardware-accelerated sensing, zero-tuning deployment, and guaranteed 0.1 pF resolution-reducing time-to-market by eliminating sensor characterization and production line calibration.

Availability

CY8C20637-24LQXIT is available at Aetrix Electronics and suitable for industrial control panels, consumer appliance interfaces, medical device keypads, and automotive cabin controls requiring stable component supply and long-term lifecycle support.

Supply support for CY8C20637-24LQXIT 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 system-on-chip solutions for embedded control, connectivity, and human-machine interface applications.

CY8C20xx7/S is part of Cypress's CapSense® PSoC® family, engineered specifically for robust, low-power capacitive touch and proximity sensing in harsh environments with minimal external components.

FAQ

What is the maximum overlay thickness supported by CY8C20637-24LQXIT?

The device supports up to 15 mm of glass or 5 mm of plastic overlay thickness, validated using its CSD PLUS™ sensing algorithm and SmartSense_EMC_PLUS auto-tuning under IEC 61000-4-3 radiated immunity testing. Performance remains stable across temperature and humidity variations due to continuous runtime recalibration of IDAC and scan parameters.

Does CY8C20637-24LQXIT require external passive components for basic CapSense operation?

No external passive components are required for standard button, slider, or proximity sensing. The device integrates the modulator capacitor (Cmod) internally and uses GPIOs for sensor electrodes and driven shield. Only an external 32 kHz crystal is optional-for precision sleep timing-and not mandatory for basic operation.

Can CY8C20637-24LQXIT operate in deep-sleep mode while maintaining proximity wake-up capability?

Yes. In Deep Sleep mode (0.1 µA typical), the device retains active CapSense hardware monitoring on selected GPIOs using the internal ILO clock. Proximity detection triggers automatic wake-up and full-scan execution without CPU involvement, enabling ultra-low-power presence sensing in battery-powered devices.

How many GPIOs support driven-shield functionality, and what is the maximum load capacitance?

Five GPIOs (P0[0]–P0[4]) support driven-shield operation. Each can drive up to 100 pF at 3 MHz, enabling robust noise rejection for long sensor traces and water-tolerant overlay designs. Shield drive is synchronized with sensor scan timing in hardware, eliminating software timing dependencies.