Infineon Technologies CY8C20636A-24LTXI

Overview

CY8C20636A-24LTXI 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), 8 KB flash/1 KB SRAM, and dedicated hardware for capacitive sensing of up to 33 buttons or 6 sliders. It operates from 1.71–5.5 V, achieves 28 µA/sensor average current in runtime scanning every 125 ms, and supports I²C (up to 400 kHz), SPI, USB 2.0 (12 Mbps), and three 16-bit timers - deployed in human-interface consumer electronics requiring robust touch response under variable EMI conditions.

For engineers reviewing the CY8C20636A-24LTXI datasheet, CY8C20636A-24LTXI pinout, CY8C20636A-24LTXI application, or CY8C20636A-24LTXI equivalent, key selection criteria include SmartSense_EMC noise immunity, configurable GPIO sink capability (25 mA per pin), integrated 10-bit ADC with internal reference, USB 2.0 compliance, and support for production-ready auto-tuned capacitive sensing without manual calibration.

Technical Context

The device implements a dedicated CapSense analog block with patented CSA_EMC and CSD sensing algorithms, coupled with SmartSense_EMC real-time auto-tuning that dynamically adjusts sensor thresholds and modulation parameters to maintain stable performance across temperature, humidity, and overlay manufacturing variance. Its Harvard-architecture M8C core executes firmware while the hardware-accelerated CapSense engine handles scan timing, IDAC calibration, and baseline tracking independently.

Four clock sources enable flexible power management: 6/12/24 MHz IMO for active mode, 32 kHz ILO for deep-sleep timing, external 32 kHz crystal, and external clock input. The internal LDO supplies regulated analog voltage (1.0 V or 1.2 V) to the CapSense block, delivering high PSRR for noise resilience during proximity or slider operation.

Key Specifications

Pinout & Package

Package: 48-pin QFN (7 mm × 7 mm, 0.5 mm pitch), RoHS-compliant, moisture sensitivity level 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT42QT2120-MAHR and STM32F072CBT6, CY8C20636A-24LTXI uniquely delivers production-ready, auto-tuned capacitive sensing with zero firmware development for touch, integrated USB HID, and hardware-accelerated EMI resilience - reducing time-to-market for certified touch interfaces by 6–9 months.

Availability

CY8C20636A-24LTXI is available at Aetrix Electronics and suitable for consumer appliance control panels, industrial HMI terminals, medical device keypads, and smart home wall controllers requiring stable component supply, long-lifecycle availability, and qualified automotive-grade traceability.

Supply support for CY8C20636A-24LTXI 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 centers and ISO 9001-certified manufacturing.

The CY8C20xx6A family targets cost-sensitive, high-volume capacitive touch applications - delivering factory-calibrated, EMC-hardened human interface functionality in compact QFN/WLCSP packages with minimal external components.

FAQ

What is the maximum number of capacitive sensors supported by CY8C20636A-24LTXI?

The CY8C20636A-24LTXI supports up to 33 capacitive buttons or 6 sliders, as confirmed in the official datasheet (Document Number 001-54459 Rev. *Y, page 1). This capacity is enabled by its dedicated CapSense hardware block and 48-pin QFN package providing 36 GPIOs - 33 allocated to sensing, 2 to I²C, and 1 to modulator capacitor.

Does CY8C20636A-24LTXI require external components for USB functionality?

No external components are required for Full-Speed USB 2.0 operation. The device integrates an internal 1.5 kΩ pull-up resistor on the USB_DP line, enabling automatic device enumeration as an HID class device. Only standard USB differential routing (controlled impedance, <15 pF trace capacitance) and proper VDD/VSS decoupling are needed per Cypress layout guidelines.

How does SmartSense_EMC differ from standard SmartSense auto-tuning?

SmartSense_EMC adds proprietary high-frequency noise immunity to baseline SmartSense auto-tuning. While SmartSense adjusts baseline, IDAC, and scan parameters for environmental stability, SmartSense_EMC specifically counters conducted and radiated EMI (e.g., from switching power supplies or RF transmitters) using adaptive filtering and frequency-hopping modulation - validated per FCC/CE radiated emission test requirements.

Can CY8C20636A-24LTXI operate from a single 3.7 V Li-ion cell without external regulators?

Yes. The device operates across 1.71–5.5 V, making it compatible with direct connection to a single-cell Li-ion battery (3.0–4.2 V range). Its internal LDO supplies regulated analog voltage to the CapSense block, and GPIOs support selectable digital I/O voltages - eliminating need for external DC-DC or LDO regulators in most portable designs.