CY7C65221-24LTXIT - USB 2.0 Controller | Infineon
MPN: CY7C65221-24LTXIT ✓ ActiveCY7C65221-24LTXIT Overview
A USB controller is an interface semiconductor that manages the physical and logical connection between a USB bus and an embedded system. The CY7C65221 family belongs to the broader USB interface controller hierarchy, where USB provides a standardized peripheral connection and I2C, SPI, and UART provide links to sensors, memory devices, displays, and communications modules.
The device supports USB 2.0 operation and combines I2C, SPI, and UART connectivity in one controller. This mixed-interface arrangement is useful when a system must bridge several peripheral buses without implementing each protocol in a separate host controller. Its USB full-speed peripheral role is suitable for configuration, control, and data-transfer systems using USB as the primary external connection.
The 24-QFN 4 x 4 mm package supports compact PCB layouts while exposing 24 package contacts for power, USB, serial interfaces, configuration, and related control functions. Because no exposed thermal-pad specification is stated in the product information, thermal design should be based on the package drawing and the final board-level copper implementation rather than an assumed heat-spreader connection.
Typical uses include USB-to-serial bridge equipment, programmable control panels, embedded test systems, industrial interface modules, sensor controllers, and compact embedded products. The I2C interface can address low-speed peripheral devices, while SPI supports higher-throughput synchronous peripherals and UART supports conventional asynchronous serial links.
The principal design consideration is interface assignment. Route USB and each serial interface only to the pins assigned to that function in the manufacturer pin description, and observe the voltage, timing, and pin-state requirements associated with UART, I2C, and SPI signaling. Firmware must also implement the required USB enumeration and peripheral-access behavior rather than treating the controller as a protocol-independent physical adapter.
This page organizes the exact package and interface information, one verified same-family candidate, package-aware comparison points, and practical integration guidance. Together, these details help engineers evaluate PCB reuse, firmware compatibility, and peripheral-bus requirements before committing the controller to a new design.
Drop-in alternatives for CY7C65221-24LTXIT — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with CY7C65221-24LTXIT (same form factor and footprint) — differing in Package, Product Type.
CY7C65211-24LTXI
✅ Drop-InContact for price
View Datasheet →CY7C65221-24LTXIT Specifications
| Product Type | USB controller |
| USB Version | USB 2.0 |
| USB Operating Role | Full-speed peripheral |
| Serial Interfaces | I2C, SPI, UART |
| Package | 24-QFN (4 x 4 mm) |
| Pin Count | 24 pins |
| Mounting Type | Surface mount |
CY7C65221-24LTXIT 24-qfn (4 x 4 mm) Pin Configuration Guide
Pin configuration for CY7C65221-24LTXIT (24-qfn (4 x 4 mm) package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for CY7C65221-24LTXIT.
Refer to the datasheet for full pin configuration.
Typical Applications
CY7C65221-24LTXIT is suitable for 6 applications: USB-to-Serial Embedded Bridge, Industrial Sensor Interface Module, Programmable Control Panel, Portable USB Test and Measurement Unit, IoT Gateway and Edge Controller, USB-Connected Embedded Configuration Adapter.
USB-to-Serial Embedded Bridge
The CY7C65221-24LTXIT fits a USB-to-serial bridge when a host computer must reach several embedded peripherals through one controller. Its USB 2.0 full-speed peripheral role provides the upstream connection, while UART, I2C, and SPI permit downstream devices with different bus requirements to coexist. A typical implementation assigns I2C to sensors or memories, SPI to higher-throughput synchronous peripherals, and UART to an asynchronous module. The 24-QFN 4 x 4 mm format also supports compact interface cards. Firmware must implement USB enumeration and each required serial protocol rather than expecting automatic protocol conversion.
Recommended
Industrial Sensor Interface Module
The CY7C65221-24LTXIT is suitable for a compact industrial sensor interface that connects a USB host to mixed sensor and actuator electronics. I2C can serve compatible low-speed sensors, SPI can support synchronous sensing devices, and UART can accommodate a local controller or communications device. USB 2.0 full-speed peripheral operation gives the module a standardized connection to configuration and monitoring software. Its 24-QFN 4 x 4 mm package helps reduce board area, although grounding, connector placement, and signal integrity still require careful layout. Validate protocol timing and logic levels for every attached sensor before production release.
Recommended
Programmable Control Panel
The CY7C65221-24LTXIT can serve as the interface hub in a programmable control panel that receives commands from a USB-connected host and routes data to panel electronics. UART can connect a local processor, I2C can address display or configuration devices, and SPI can serve memory or higher-speed peripherals. The full-speed USB peripheral role supports enumeration as a USB device for control software. Using one controller reduces the number of separate interface devices, while the compact 24-QFN 4 x 4 mm package simplifies dense panel layouts. Power sequencing and bus contention must be managed in firmware and through the board-level enable design.
Recommended
Portable USB Test and Measurement Unit
The CY7C65221-24LTXIT fits a portable USB test and measurement instrument that connects a host computer to probes, programmable peripherals, and service interfaces. USB 2.0 full-speed peripheral operation supports a recognizable control channel, while UART, I2C, and SPI provide access to devices using different communication methods. A compact 24-QFN 4 x 4 mm package is useful when the electronics must fit into a handheld enclosure. Keep test-signal paths away from sensitive serial lines, use controlled grounding, and validate timing margins under the intended cable, connector, and peripheral loading conditions.
Recommended
IoT Gateway and Edge Controller
The CY7C65221-24LTXIT is applicable to an IoT gateway or edge controller that receives configuration from a USB host and communicates with local sensors, memory, and radio-related modules. I2C supports compatible sensor addressing, SPI supports higher-throughput peripherals, and UART supports a conventional serial link to an embedded controller or communications module. The full-speed USB peripheral role allows the gateway to enumerate as a standard USB device. Its 24-QFN 4 x 4 mm package conserves board space in compact edge hardware. Designers should define bus ownership, isolation requirements, and firmware recovery behavior before attaching multiple peripherals.
Recommended
USB-Connected Embedded Configuration Adapter
The CY7C65221-24LTXIT can act as the central controller in a USB-connected embedded configuration adapter designed to program or monitor several internal modules. A host-side application communicates over USB, and the controller distributes commands through UART, I2C, or SPI according to the attached module interface. This arrangement simplifies a shared physical connection while retaining flexibility for diverse peripherals. The 24-QFN 4 x 4 mm package supports compact adapter hardware, but implementation quality depends on correct pin assignment, connector protection, and disciplined firmware state handling. Use the manufacturer pin description table as the basis for every routing decision.
Recommended
Recommended Products Summary
Engineering reference data for CY7C65221-24LTXIT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | CY7C65211-24LTXI |
|---|---|---|
| Brand | Infineon Technologies | Infineon Technologies |
| Package | 24-QFN (4 x 4 mm) | 24-QFN (4 x 4 mm) |
| Product Type | USB controller | USB-Serial bridge |
| USB Version | USB 2.0 | USB 2.0 |
| Serial Interfaces | UART, I2C, SPI | UART, I2C, SPI |
| Pin Count | 24 pins | 24 pins |
Key Differentiators
- Direct selection for the CY7C65221 controller implementation (vs CY7C65211-24LTXI)
- CAPSENSE is a documented feature of the same-family candidate (vs CY7C65211-24LTXI)
- Package compatibility supports PCB reuse with verification (vs CY7C65211-24LTXI)
Design Notes
Route USB, UART, I2C, and SPI as separate functional groups and assign each external device unambiguously to one bus. Place the controller's decoupling and required support components close to their associated pins, then verify the arrangement against the manufacturer pin-description table and recommended application diagram. Preserve a direct return path for each high-speed interface and keep the USB connector area physically separated from sensitive analog or precision timing circuits.
Do not treat a shared 24-QFN outline as proof of immediate drop-in compatibility. Before substituting CY7C65211-24LTXI for CY7C65221-24LTXIT, compare every numbered pin, power pin, configuration input, interface enable, and exposed-pad connection in both manufacturer datasheets. Also confirm operating-voltage limits, USB timing, UART and I2C timing, SPI clock limits, and the required firmware functions.
Use the supply and decoupling recommendations in the manufacturer datasheet, including the required capacitor types, voltage ratings, and placement. Check startup behavior for every powered peripheral and define a sequence that prevents I2C or SPI devices from driving a bus before the controller is ready. If multiple peripherals can contend for a shared line, add the required pull-up or isolation components and verify contention in software.
For USB-connected boards, minimize trace stubs and discontinuities, provide the USB data-path layout specified by the manufacturer, and keep switching or high-current paths away from the interface pins. For SPI, keep the clock and return path together and control edge rates through the source and load configuration. For UART, ensure the external transceiver and connector do not introduce excessive capacitance on the serial signal.
Compliance Information
The product information does not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status for the exact MPN.