Infineon Technologies CY8C20237-24LKXI

Overview

CY8C20237-24LKXI from Cypress Semiconductor is a 1.8 V CapSense® controller with SmartSense™ auto-tuning, implementing a dedicated M8C 8-bit Harvard-architecture CPU (24 MHz max), supporting up to 31 capacitive buttons, 6 sliders, and proximity sensing on 48-pin QFN package with 8 KB flash and 1 KB SRAM. It delivers 0.1 pF sensitivity, 28 µA/sensor active current, and operates from –40 °C to +85 °C for industrial HMI touch interfaces.

For engineers reviewing the CY8C20237-24LKXI datasheet, CY8C20237-24LKXI pinout, CY8C20237-24LKXI application, or CY8C20237-24LKXI equivalent, key selection criteria include CSD PLUS™ sensing algorithm performance, SmartSense_EMC_PLUS runtime auto-tuning capability, driven-shield support on five GPIOs, I2C slave speed options (50/100/400 kHz), and low-power deep-sleep mode (0.1 µA typical).

Technical Context

The device integrates a dedicated CapSense analog block with patented Capacitive Sigma Delta PLUS (CSD PLUS™) sensing engine, enabling hardware-accelerated scan of up to 31 inputs without CPU intervention. Its internal 1.2 V analog reference and configurable IDAC support high SNR across varying overlay thicknesses (15 mm glass, 5 mm plastic).

SmartSense_EMC_PLUS operates autonomously in run time-dynamically adjusting sensor parameters including IDAC current, scan resolution, and baseline tracking-to maintain stable operation amid environmental drift, PCB process variation, and conducted/radiated noise. The driven shield function on five GPIOs enables robust water tolerance and metal-immune proximity detection.

Key Specifications

Pinout & Package

48-pin QFN (7 mm × 7 mm, 0.5 mm pitch), thermally enhanced with exposed thermal pad. Package supports reflow per JEDEC J-STD-020D (peak 260 °C).

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 STM32F070CBT6, CY8C20237-24LKXI provides out-of-box SmartSense auto-tuning, hardware-accelerated CSD PLUS™ scanning, and dedicated CapSense resources-reducing time-to-market for production-ready touch interfaces without custom firmware tuning.

Availability

CY8C20237-24LKXI is available at Aetrix Electronics and suitable for industrial HMI, consumer appliance control, medical device interfaces, and automotive cabin panels requiring stable component supply, long-term lifecycle support, and qualified automotive-grade variants.

Supply support for CY8C20237-24LKXI 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 belongs to Cypress's CapSense® controller product line, engineered specifically for robust, low-power, self-calibrating capacitive touch systems in harsh electrical and environmental conditions.

FAQ

Does CY8C20237-24LKXI require external tuning components for basic button operation?

No. The device integrates all required sensing circuitry-including IDACs, comparators, and modulator capacitors-and uses SmartSense_EMC_PLUS to auto-configure parameters at startup and during runtime. Only an external C_EXT capacitor (typically 2.2 nF) on P3[7] is mandatory for sigma-delta modulation; no resistor networks or trim pots are needed.

Can CY8C20237-24LKXI drive LEDs directly from GPIO pins?

Yes-ports 0 and 1 support 5 mA source current and 25 mA sink current per pin, enabling direct LED drive with appropriate series resistors. However, total combined sink current must not exceed 120 mA across all GPIOs, and port 1's regulated I/O mode must be disabled if using higher-current LED loads.

What is the maximum overlay thickness supported for proximity sensing?

The device achieves reliable proximity detection through up to 15 mm of glass or 5 mm of plastic overlay, verified per Cypress application note AN71905. Performance depends on electrode size, shield configuration, and ambient EMI; actual range is typically 10–12 mm in production with optimized layout and driven shield enabled.

Is the internal 32 kHz oscillator sufficient for accurate sleep timing in battery-powered applications?

For moderate accuracy requirements (±5% over –40 °C to +85 °C), the internal ILO suffices. For tighter timing-such as precise 1-second wake intervals or watchdog timeout consistency-Cypress recommends connecting an external 32.768 kHz crystal to XTAL32, which improves stability to ±20 ppm and eliminates temperature-induced drift.