CY7C65221-24LTXI - USB 2.0 I2C/SPI/UART Bridge | Infineon
MPN: CY7C65221-24LTXI ✓ ActiveCY7C65221-24LTXI Overview
A USB interface controller is an interface IC that bridges the host-oriented Universal Serial Bus with embedded serial peripherals. In the system hierarchy, it belongs to integrated circuits, interface ICs, and USB interface controllers. Such devices simplify USB connectivity when a product needs to expose configuration, control, logging, or data-transfer functions without implementing a complete USB host or complex external transceiver architecture.
The CY7C65221-24LTXI supports USB 2.0 together with I2C, SPI, and UART interfaces. Its 1.71 V minimum operating supply permits integration with low-voltage embedded systems, while the 5.5 V maximum provides compatibility with common 3.3 V and 5 V rails. The listed 20 mA supply-current figure and 1.71 V to 5.5 V supply range provide useful initial points for power-budget and regulator-selection work, although detailed current consumption across operating modes is not included in the supplied data.
The controller is offered in a compact 24-QFN package measuring 4 x 4 mm. This surface-mount construction reduces board area compared with larger leaded packages but requires careful escape routing, thermal-pad soldering, and assembly-process control. The exposed-pad package also preserves electrical and thermal performance when its land pattern is implemented according to the manufacturer footprint guidance.
Typical uses include USB-to-serial configuration ports, embedded control and debug interfaces, data acquisition front ends, industrial peripherals, and communication accessories. In each case, the device can serve as the USB-facing controller while I2C, SPI, or UART connects to sensors, memories, converters, or other local logic. Firmware, protocol support, and enumeration behavior must be confirmed against the manufacturer documentation before a design is released.
The primary design consideration is USB signal integrity. Place the device according to the recommended footprint, provide a continuous ground reference, decouple the supply close to the pins, and route D+ and D- as a controlled impedance pair with minimal stubs. The 24-QFN thermal pad should be connected to the appropriate ground or power plane using the documented assembly pattern.
This product record consolidates verified distributor listings, package information, interface capabilities, operating limits, and relevant replacement-search results. It also highlights where engineers must consult the exact manufacturer datasheet and footprint files rather than relying on generic catalog data.
Drop-in alternatives for CY7C65221-24LTXI — 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 CY7C65221-24LTXI (same form factor and footprint) — differing in Mounting Type.
CY7C65211-24LTXI
✅ Drop-InContact for price
View Datasheet →CY7C65211A-24LTXI
✅ Drop-In📋 Reference alternative (not in catalog)
CY7C65221-24LTXI Specifications
| Device Type | USB Full-Speed Peripheral Controller |
| USB Standard | USB 2.0 |
| Serial Interfaces | I2C, SPI, UART |
| Operating Supply Voltage Range | 1.71 V to 5.5 V |
| Supply Current | 20 mA |
| Operating Temperature Range | -40°C to +85°C |
| Temperature Grade | Industrial |
| Package Type | 24-QFN (4 x 4 mm) Exposed Pad |
| Manufacturer Package Code | HQCCN |
| Terminal Count | 24 |
| Mounting Type | No Lead Surface Mount |
| Package Shape | Square |
| Moisture Sensitivity Level | MSL 3 (168 hours) |
| ECCN | EAR99 |
| HTS Code | 8542.39.0001 |
CY7C65221-24LTXI square Pin Configuration Guide
Pin configuration for CY7C65221-24LTXI (square 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 CY7C65221-24LTXI.
Refer to the datasheet for full pin configuration.
Typical Applications
CY7C65221-24LTXI is suitable for 6 applications: Embedded USB Configuration Port, Industrial Data-Acquisition Front End, USB-to-SPI Configuration Bridge, IoT Sensor and Gateway Interface, Portable Diagnostic and Service Tool, Test and Measurement Controller.
Embedded USB Configuration Port
The CY7C65221-24LTXI fits an embedded configuration port where a USB host must access local control logic. Its verified USB Full-Speed Peripheral role and support for I2C, SPI, and UART provide several ways to reach sensors, memory, or a board controller. The 24-QFN 4 x 4 mm package conserves board area, while the 1.71 V to 5.5 V range supports low-voltage embedded rails. A practical implementation places the USB controller close to the connector, routes D+ and D- as a differential pair, and verifies enumeration and peripheral drivers before production.
Recommended
Industrial Data-Acquisition Front End
The CY7C65221-24LTXI is suitable for an industrial data-acquisition front end that collects measurements from a USB host and forwards them through embedded serial interfaces. Its industrial-grade -40°C to +85°C range and 1.71 V to 5.5 V supply operation align with compact control equipment. I2C can connect low-bandwidth sensors, SPI can serve flash or ADC components, and UART can provide a simple local diagnostic path. The 20 mA listed supply-current figure should be checked against the complete system power budget before selecting the rail and decoupling network.
Recommended
USB-to-SPI Configuration Bridge
The CY7C65221-24LTXI can bridge a USB host to SPI-managed logic in a configuration or programming system. SPI is well suited to flash devices, serializers, and register-oriented peripherals, while the USB interface provides a convenient connection to a standard computer. Using the 24-QFN package reduces the footprint compared with larger USB bridge packages. The implementation should keep SPI traces short, provide pull resistors where required by the attached device, confirm the device's supported voltage level, and validate USB suspend, resume, and bus-powered behavior against the manufacturer requirements.
Recommended
IoT Sensor and Gateway Interface
The CY7C65221-24LTXI fits an IoT gateway that accepts administrative traffic from a USB host and distributes commands to local sensors. Its I2C interface can connect compatible sensors or configuration devices, while UART offers a straightforward link to a low-power communications module and SPI can access higher-bandwidth peripherals. The low-voltage 1.71 V to 5.5 V operating range supports mixed embedded power systems, and the 4 x 4 mm QFN package leaves board area for sensors. Firmware should enumerate as the intended peripheral class and expose secure controls appropriate to the finished gateway.
Recommended
Portable Diagnostic and Service Tool
The CY7C65221-24LTXI is appropriate for a portable diagnostic tool that exposes internal serial buses to a technician's laptop. The controller supports I2C, SPI, and UART, allowing one USB connection to reach sensors, EEPROMs, and service interfaces without building several separate adapters. Its compact 24-QFN footprint is valuable in a handheld enclosure, while USB provides a familiar service connection. Designers should budget for battery and rail interaction, apply USB ESD protection as appropriate, and verify that the tool remains functional across the full -40°C to +85°C operating range required by the product.
Recommended
Test and Measurement Controller
The CY7C65221-24LTXI can serve as the USB-facing controller in test and measurement equipment that sends commands to local instrumentation. I2C is useful for low-speed configuration chips, SPI can reach high-speed converters and memory, and UART can connect legacy instruments. The 1.71 V to 5.5 V range and 20 mA listed supply current make the controller practical for compact mixed-signal systems. For dependable results, separate sensitive analog returns from digital switching paths, maintain a continuous USB ground reference, and verify protocol timing and firmware behavior against each connected instrument.
Recommended
Recommended Products Summary
Engineering reference data for CY7C65221-24LTXI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | CY7C65211-24LTXI | CY7C65211A-24LTXI |
|---|---|---|---|
| Brand | Infineon Technologies | Infineon Technologies | Infineon Technologies |
| Package | 24-QFN (4 x 4 mm) | 24-QFN package family | 24-QFN package family |
| USB Standard | USB 2.0 | USB 2.0 | USB 2.0 |
| Device Role | USB Full-Speed Peripheral | USB-Serial bridge | USB-Serial bridge |
| Serial Interfaces | I2C, SPI, UART | UART, I2C, SPI | UART, I2C, SPI |
| Additional Features | CAPSENSE and BCD status not specified | CAPSENSE | CAPSENSE, BCD |
Key Differentiators
- Verified full-speed peripheral role (vs CY7C65211A-24LTXI)
- Single-device access to three serial buses (vs CY7C65211-24LTXI)
- Compact exposed-pad integration (vs CY7C65211-24LTXI)
Design Notes
Route the USB D+ and D- conductors as a controlled-impedance differential pair with continuous reference to the ground plane, minimize stubs and vias, and avoid splitting the return path beneath the pair. Keep the controller and its USB transceiver path physically close to the connector. Because the supplied results do not include the complete pin table or layout guidance, use the manufacturer footprint and reference design rather than inferring placement from the 4 x 4 mm package dimensions.
Design the 1.71 V to 5.5 V supply network so it remains stable across the controller's operating states and any attached load. Place the manufacturer-recommended bypass capacitors close to the supply and ground pins and provide additional bulk capacitance only where justified by the complete USB load transient. The listed 20 mA supply-current value is useful for a preliminary budget, but it should not replace worst-case current verification from the manufacturer datasheet.
The 24-QFN exposed pad is part of the package thermal and electrical design, not merely an optional copper pad. Follow the manufacturer land pattern, solder-mask and paste recommendations, and assembly profile exactly. Keep the thermal pad's copper connection consistent with the device's ground or power guidance. A small 4 x 4 mm footprint limits heat-spreading area, so thermal performance should be checked against the maximum ambient temperature and sustained operating load.
Do not treat a shared 24-QFN package as proof that CY7C65211 or CY7C65211A is a true drop-in replacement. Verify every pin, supply sequencing requirement, USB descriptor, interface timing, firmware dependency, and exposed-pad connection before substitution. Also avoid using the CY7C65221-24LTXIT tape-and-reel ordering code as an engineering alternative because it is the same electrical device with different shipment packaging rather than a distinct replacement.
Compliance Information
The verified technical listing reports ECCN EAR99 and HTS code 8542.39.0001. Search snippets mention RoHS and REACH fields but do not provide complete status text, so those fields remain unknown. No AEC-Q100 qualification is identified for the industrial-temperature target.
