Infineon Technologies CY8C21334B-24PVXI

Overview

CY8C21334B-24PVXI from Cypress Semiconductor is a PSoC® 1 programmable system-on-chip CapSense® controller with SmartSense™ auto-tuning, supporting up to 21 capacitive buttons or 4 sliders and proximity sensing. It integrates an M8C 8-bit Harvard-architecture CPU (24 MHz), 8 KB Flash/512 B SRAM, four analog Type E blocks, and four digital PSoC blocks. Operating from 2.4 V to 5.25 V (or down to 1.0 V with on-chip SMP), it targets touch interface applications in industrial HMI and consumer electronics.

For engineers reviewing the CY8C21334B-24PVXI datasheet, CY8C21334B-24PVXI pinout, CY8C21334B-24PVXI application, or CY8C21334B-24PVXI equivalent, key selection criteria include CapSense® channel count, SmartSense™ runtime auto-tuning capability, analog block configuration flexibility, GPIO drive strength (25 mA sink), and I²C/SPI/UART peripheral support for embedded touch subsystem integration.

Technical Context

The device implements a dedicated CapSense® CSD (Capacitive Sigma-Delta) sensing engine with patented algorithm and driven-shield architecture for water tolerance and metal-immune proximity detection. SmartSense_EMC auto-tuning dynamically adjusts sensor parameters-including IDAC current, scan resolution, and baseline tracking-during runtime without host intervention.

Its M8C core executes user firmware while coordinating configurable digital blocks (timers, PWMs, UART, SPI, CRC, PRS) and analog blocks (comparators with DAC reference, dual 10-bit ADCs) via global interconnect buses. All 28 GPIOs support interrupt, configurable drive modes, and analog mux routing to the internal analog bus.

Key Specifications

Pinout & Package

Package: 28-pin SSOP (SOIC-compatible, body width 7.6 mm, lead pitch 0.65 mm). Pinout validated per datasheet Rev. *H, Page 12 (28-pin Part Pinout).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CapSense® controller applications.

Compared with CY8C21434B-24LFXI, the CY8C21334B-24PVXI offers identical CapSense® functionality in a mature, through-hole-compatible SSOP package ideal for prototyping and legacy assembly; versus CY8C201A0-24LQXI, it delivers full SmartSense™ and memory headroom for complex UIs - making it the balanced choice for production-ready industrial touch systems.

Availability

CY8C21334B-24PVXI is available at Aetrix Electronics and suitable for home appliance control panels, industrial HMI terminals, and medical device keypads requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for CY8C21334B-24PVXI 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 control, sensing, and connectivity applications, with global R&D and manufacturing infrastructure.

The CY8C21x34B product line delivers integrated CapSense® controllers optimized for robust, low-cost, self-calibrating touch interfaces - targeting applications where mechanical switch replacement, environmental resilience, and rapid UI development are primary design goals.

FAQ

What is the maximum number of CapSense® electrodes supported by CY8C21334B-24PVXI?

The device supports up to 21 capacitive buttons or 4 sliders, implemented using its four analog Type E blocks and three digital blocks. Electrode count depends on configuration: a 4-slider setup consumes more analog resources than 21 discrete buttons. The 28-pin SSOP package provides 24 GPIOs usable for electrodes, shields, or other functions - actual electrode count is constrained by routing and mutual capacitance limits, not just pin count.

Does CY8C21334B-24PVXI require an external crystal for accurate timing?

No. It includes an internal main oscillator (IMO) rated at ±2.5% accuracy across 24 MHz and 48 MHz frequencies, sufficient for CapSense® scanning and UART communication. An external crystal (up to 24 MHz) is optional and only needed if tighter timing tolerance (e.g., <±0.5%) is required for specific serial protocols or synchronization tasks - most touch applications operate reliably using the IMO alone.

How does SmartSense™ Auto-Tuning handle environmental changes during operation?

SmartSense_EMC continuously monitors baseline capacitance and signal-to-noise ratio during active scanning, then automatically adjusts IDAC current, scan resolution, and filtering parameters in real time. It compensates for slow drift (e.g., humidity-induced electrode capacitance shift) and fast transients (e.g., water droplet contact), maintaining consistent finger detection thresholds without host CPU intervention or firmware updates.

Can CY8C21334B-24PVXI interface directly with a 3.3 V microcontroller over I²C?

Yes. Its GPIOs are 5 V tolerant and support configurable drive modes, including open-drain. When configured as I²C slave, P1[0] (SDA) and P1[1] (SCL) operate at VDD level (2.4–5.25 V), so a 3.3 V MCU can interface directly using standard pull-up resistors to 3.3 V - no level shifter is required. The device's I²C block supports standard-mode (100 kHz) and fast-mode (400 kHz) operation.