Infineon Technologies CY8C20234-12SXI

Overview

CY8C20234-12SXI from Infineon Technologies (formerly Cypress) is a programmable 8-bit PSoC® System-on-Chip with integrated CapSense® capacitive sensing engine, M8C CPU core running up to 12 MHz, 8 KB flash, 512 bytes SRAM, and 28 GPIOs supporting configurable analog inputs and 20-mA sink drive. It operates from 2.4 V to 5.25 V across –40 °C to +85 °C and targets embedded touch interface applications such as industrial control panels and consumer appliance interfaces.

For engineers reviewing the CY8C20234-12SXI datasheet, CY8C20234-12SXI pinout, CY8C20234-12SXI application, or CY8C20234-12SXI equivalent, key selection criteria include its dedicated hardware-accelerated CapSense block, I²C/SPI communication support at up to 400 kHz / 3 MHz, on-chip 1.8 V analog reference, low-dropout regulator for port 1 I/O, and ISSP in-system programming capability.

Technical Context

The CY8C20234-12SXI implements a Harvard-architecture M8C CPU core with deterministic interrupt handling and dual-clock domains: a 6/12 MHz internal main oscillator (IMO) and a 32 kHz internal low-speed oscillator (ILO) for sleep/wake timing. Its CapSense block uses relaxation oscillator-based charge-transfer measurement with hardware scanning logic, eliminating external RC components for button/slider/proximity sensing.

All 28 GPIOs are routed to a common analog multiplexer bus enabling simultaneous connection of any combination of pins to the CapSense comparator and IDAC reference buffer. The device integrates a 3.0 V LDO for regulated digital I/O on Port 1 (20 mA total source), selectable pull-up/open-drain/CMOS drive modes, and partial flash update support - critical for field firmware maintenance in sealed touch devices.

Key Specifications

Pinout & Package

Package: 28-pin SOIC (Small Outline Integrated Circuit), 300 mil width, RoHS-compliant, JEDEC MS-012AC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY8C20247-24LQX and MTCH101-I/ST, the CY8C20234-12SXI uniquely balances self-contained firmware execution, integrated analog regulation, and SOIC manufacturability - making it optimal for mid-volume industrial and appliance designs requiring field-upgradable touch logic without external analog support components.

Availability

CY8C20234-12SXI is available at Aetrix Electronics and suitable for industrial HMI panels, home appliance control interfaces, medical device keypads, and smart thermostat interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for CY8C20234-12SXI 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

Infineon Technologies is a global semiconductor leader headquartered in Munich, Germany, specializing in power management, sensing, connectivity, and security solutions for industrial, automotive, and IoT markets.

The CY8C20x34 family was originally developed by Cypress Semiconductor and continues under Infineon's PSoC® portfolio to deliver highly integrated, programmable capacitive touch controllers targeting cost-sensitive, reliability-critical embedded human interface applications.

FAQ

Does CY8C20234-12SXI support mutual-capacitance sensing?

No. The CY8C20234-12SXI implements only self-capacitance sensing using its relaxation oscillator-based CapSense block. Mutual-capacitance scanning requires PSoC 4 or later families with dedicated CSD (CapSense Sigma-Delta) hardware. This device achieves robust button/slider/proximity detection via patented self-capacitance algorithms with automatic baseline tracking and noise filtering.

Can the internal 3.0 V LDO power external circuitry?

No. The internal LDO is dedicated solely to regulating Port 1 I/O voltage and is not designed to source current to external loads. Its 20 mA total output capacity is allocated across all eight Port 1 pins and must not be exceeded. External circuitry requiring regulated 3.0 V should use a discrete LDO or DC-DC converter.

Is ISSP programming supported in-circuit after soldering?

Yes. In-system serial programming (ISSP) uses only VDD, VSS, and two dedicated programming pins (typically P1[6] and P1[7]), allowing full firmware programming and debugging through standard test pads or edge connectors without removing the IC from the PCB. No external programmer socket or JTAG header is required.

What is the maximum recommended overlay thickness for reliable touch detection?

With standard tuning and 1.0 mm copper trace electrodes, the CY8C20234-12SXI reliably detects touch through up to 8 mm of glass or 10 mm of plastic overlay. Performance depends on electrode size, spacing, and firmware tuning parameters - Cypress' CapSense Design Guide (AN2397) provides validated layout rules and sensitivity optimization procedures.