Infineon Technologies CY8C20636AN-24LTXIT

Overview

CY8C20636AN-24LTXIT from Cypress Semiconductor is a programmable 1.8 V CapSense® controller with SmartSense™ auto-tuning, supporting up to 33 capacitive buttons or 6 sliders. It integrates an M8C 8-bit Harvard CPU (24 MHz), 8 KB flash/1 KB SRAM, full-speed USB 2.0 (12 Mbps), and operates from 1.71–5.5 V. Used in touch-enabled human interface modules for industrial HMI and consumer appliances.

For engineers reviewing the CY8C20636AN-24LTXIT datasheet, CY8C20636AN-24LTXIT pinout, CY8C20636AN-24LTXIT application, or CY8C20636AN-24LTXIT equivalent, key selection criteria include SmartSense_EMC noise immunity, low-power wake-up timing (125 ms scan interval), GPIO sink capability (25 mA per pin), and QFN-48 package compatibility with 33-sensor layouts.

Technical Context

The device implements a dedicated hardware CapSense block with dual sensing algorithms-CSA_EMC and CSD-enabling robust self-capacitive and mutual-capacitive scanning without external components. Its SmartSense_EMC auto-tuning continuously adjusts baseline, threshold, and IDAC settings during runtime to maintain performance across environmental drift and EMI exposure.

It features four clock sources: 6/12/24 MHz IMO, 32 kHz ILO, external 32 kHz crystal, and external clock input. The analog subsystem includes a 10-bit incremental ADC, two high-speed comparators, internal LDO (1.8/2.5/3.0 V), and global analog bus for ganged proximity sensing.

Key Specifications

Pinout & Package

Package: 48-pin QFN (7 mm × 7 mm, 0.5 mm pitch), thermally enhanced with exposed pad. Pin count and layout optimized for 33-sensor configurations with dedicated USB D+/D−, I²C, and modulator capacitor terminals.

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 AT42QT2120-MMHR, CY8C20636AN-24LTXIT provides field-upgradable firmware, integrated USB HID, and real-time SmartSense_EMC tuning-making it uniquely suited for production touch systems requiring regulatory certification and long-term EMI resilience.

Availability

CY8C20636AN-24LTXIT is available at Aetrix Electronics and suitable for industrial HMI panels, consumer appliance interfaces, medical device keypads, and smart home thermostats requiring stable component supply and long-lifecycle support.

Supply support for CY8C20636AN-24LTXIT 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 sensing applications, with global R&D and manufacturing infrastructure.

This device belongs to the PSoC® CY8C20xx6A family, engineered specifically for robust, low-power capacitive touch interfaces in cost-sensitive, high-volume consumer and industrial products.

FAQ

What is the role of the MOD pin on CY8C20636AN-24LTXIT?

The MOD pin connects to an external modulator capacitor (typically 2.2 nF) used by the IDAC-based CapSense charge-transfer circuit. It establishes the reference capacitance for baseline calibration and enables precise delta-C measurement across all 33 sensing channels. Incorrect capacitor value or PCB parasitic coupling here directly degrades SNR and causes false touch detection.

Does CY8C20636AN-24LTXIT require external crystal for USB operation?

No. Full-speed USB 2.0 operation uses the internal 24 MHz IMO clock, which is factory-trimmed to ±2% accuracy-within USB specification limits. An external 32 kHz crystal is optional and only required for high-precision sleep/wake timing or watchdog calibration, not for USB functionality.

How does SmartSense_EMC differ from standard SmartSense auto-tuning?

SmartSense_EMC adds spread-spectrum modulation and correlated double sampling to the base SmartSense algorithm. It actively rejects high-frequency conducted and radiated noise (up to 1 GHz), enabling reliable operation near switching power supplies, motors, and RF transmitters-where standard SmartSense may fail due to insufficient EMI margin.

Can CY8C20636AN-24LTXIT drive LEDs directly from GPIO pins?

Yes. Ports 0–4 support configurable sink current up to 25 mA per pin (120 mA total). This allows direct LED driving without external drivers-ideal for status indicators synchronized with touch events. Source current is limited (5 mA on ports 0/1, 1 mA on others), so common-anode LED configurations require external pull-up or transistor buffering.