Infineon Technologies CY8C20636A-24LQXI

Overview

CY8C20636A-24LQXI 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, consumes 28 µA/sensor in active scan mode (125 ms interval), 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-24LQXI datasheet, CY8C20636A-24LQXI pinout, CY8C20636A-24LQXI application, or CY8C20636A-24LQXI equivalent, key selection criteria include SmartSense_EMC noise immunity, on-chip LDO PSRR, configurable GPIO sink capability (25 mA per pin), USB 2.0 compliance, and support for ganged proximity sensing via internal analog bus.

Technical Context

The device implements a dedicated CapSense analog block with patented CSA_EMC and CSD sensing algorithms, coupled with real-time SmartSense_EMC auto-tuning that dynamically adjusts sensor thresholds and IDAC settings to maintain stable performance across temperature, humidity, and overlay manufacturing variance. Its internal 1 V/1.2 V analog reference and low-dropout regulator deliver high PSRR for noise-immune sensing.

It features four clock sources - 6/12/24 MHz IMO, 32 kHz ILO, external 32 kHz crystal, and external clock input - enabling precise timing control for both CapSense scanning and system-level USB/I²C/SPI synchronization without external timing components.

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 AT42QT2120-MAHR and STM32F072CBT6, CY8C20636A-24LQXI delivers deterministic CapSense performance with zero calibration overhead, integrated USB HID reporting, and hardware-accelerated EMC immunity - reducing time-to-certification and production test burden for touch-enabled products.

Availability

CY8C20636A-24LQXI is available at Aetrix Electronics and suitable for consumer appliance control panels, industrial HMI interfaces, medical device overlays, and automotive cabin controls requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for CY8C20636A-24LQXI 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 systems, emphasizing configurable analog/digital blocks and system-on-chip integration.

CY8C20xx6A is part of the PSoC® CapSense® controller family, engineered specifically for robust, low-power, production-ready capacitive touch interfaces - eliminating manual tuning and simplifying EMI-compliant design across consumer, industrial, and medical markets.

FAQ

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

The CY8C20636A-24LQXI supports up to 33 capacitive buttons or 6 sliders, depending on configuration. This is enabled by its dedicated CapSense hardware block and flexible GPIO mapping across ports 0–1. The 24-pin QFN package allocates 17 GPIOs for sensing, with remaining pins reserved for USB, I²C, reset, and power. Sensor count is constrained by physical pin count and internal analog bus routing limits - not firmware memory.

Does CY8C20636A-24LQXI require external components for basic CapSense operation?

No external passive components are required for basic capacitive sensing. The device integrates IDACs, analog comparators, internal references, and programmable scan clocks. Only a single modulator capacitor (typically 2.2 nF) is needed on CSN pin for CSD operation, and optional 32.768 kHz crystal for precise sleep timing. USB and I²C interfaces use internal termination - no external resistors or level shifters needed.

How does SmartSense_EMC differ from standard SmartSense auto-tuning?

SmartSense_EMC extends base SmartSense with a proprietary algorithm that actively monitors high-frequency noise on sensor lines and adapts scan parameters - including modulation frequency, IDAC range, and averaging depth - to suppress conducted and radiated EMI. It is validated to meet FCC Part 15 Class B and CE EN 55032 limits without additional shielding, unlike standard SmartSense which focuses only on environmental drift compensation.

Can CY8C20636A-24LQXI operate in deep-sleep mode while maintaining USB connectivity?

No - USB functionality is disabled in Deep Sleep mode (0.1 µA). The device supports USB only in Active or Sleep modes. In Deep Sleep, only the 32 kHz ILO remains active to drive watchdog and sleep timers; USB PHY is powered down. To maintain USB presence, use Sleep mode (1.1 µA) with periodic wake-up for polling, or implement external USB suspend/resume handshaking via host-controlled reset assertion.