The MCP2221A-I/ML: A Versatile USB-to-Serial Bridge for Embedded Systems

In the realm of embedded electronics and prototyping, seamlessly connecting a modern computer to legacy or resource-constrained serial devices remains a fundamental requirement. The Microchip MCP2221A-I/ML stands out as a robust, compact, and highly capable solution designed to bridge this gap efficiently. This USB 2.0-compliant converter provides a straightforward path to UART, I2C, and GPIO interfaces, making it an indispensable tool for engineers and hobbyists alike.

Functioning as a USB-to-UART/I2C serial converter bridge, the MCP2221A integrates multiple critical components into a single 5x5mm VQFN package. It eliminates the need for complex driver development on the host computer, as it is recognized as a standard Human Interface Device (HID), ensuring plug-and-play compatibility across major operating systems including Windows, macOS, and Linux. This feature drastically simplifies deployment and reduces development time.

The core strength of the MCP2221A lies in its multi-protocol support. For UART communication, it provides a fully featured serial port with RTS/CTS hardware flow control, essential for reliable high-speed data transfer without loss. Simultaneously, its dedicated I2C port operates as a master, supporting standard (100 kHz) and fast (400 kHz) modes, enabling the chip to read from and write to a vast ecosystem of I2C sensors, memories, and other peripherals directly.

Beyond data conversion, the device is equipped with four user-configurable GPIO pins and a dedicated serial data pin. These can be programmed for various functions, including digital input/output, LED control, or serving as the dedicated pins for I2C communication. Furthermore, the MCP2221A includes an on-board 256-bit one-time programmable (OTP) memory, allowing for the customization of key vendor details like the Product ID, Manufacturer String, and Serial Number, which is invaluable for product branding and differentiation in end designs.

A notable feature is the integrated digital-to-analog converter (DAC) with a 5-bit resolution. This allows for generating a simple analog voltage reference, adding another layer of utility for control applications. The converter also manages power wisely, supporting USB suspend and resume states, which is crucial for power-sensitive applications.

In practical terms, the MCP2221A is perfectly suited for a wide range of applications, from USB-to-serial adapters for console management of network equipment to acting as a USB-based I2C master for debugging and programming systems. Its reliability and small form factor also make it an excellent choice for embedding directly into final products to provide a convenient service or programming interface.

ICGOODFIND: The Microchip MCP2221A-I/ML is a powerhouse of connectivity, masterfully combining USB, UART, and I2C interfaces with flexible GPIO in a tiny, easy-to-use package. Its HID-class compliance ensures universal compatibility, making it one of the most versatile and developer-friendly bridge solutions on the market for prototyping and production.

Keywords:

USB-to-UART Converter

I2C Master

HID Class Device

GPIO Pins

Hardware Flow Control