MCP2221A-I/SL

MCP2221A-I/SL is Microchip’s USB 2.0 full‑speed USB-to-UART/I2C bridge plus GPIO. It lets a PC or microcontroller talk to a UART serial port and to an I2C bus through a single USB device.
Key features
- Interfaces: one UART (TX/RX), I2C master (SCL/SDA), and 4 GPIOs (GP0–GP3).
- USB role: device connected to host; routed via Microchip’s driver/API for UART, I2C, and GPIO control.
- Power: bus-powered from USB; IO levels come from VDDIO (software-configurable).
- Temperature/package: “I” = Industrial temperature range; “SL” = RoHS lead-free package.
- Use cases: PC-to-mirmware communication, USB-I2C expansion, quick lab prototyping, sensor or EEPROM access via USB.
Why choose it
- Simplifies adding USB connectivity to embedded firmware without custom USB stack.
- Works with Microchip software libraries and is supported by available drivers.

Equivalent products (USB-to-UART/GPIO bridges with similar functionality):
- FTDI: FT232R, FT232H, FT231X
- Silicon Labs: CP2102N, CP2104
- Prolific: PL2303HX, PL2303TA
- WCH: CH340G, CH340C
Note: features differ (GPIO count, I2C/SPI capability, voltage levels). Check each datasheet to match UART, I2C master, GPIOs, and voltage requirements.

MCP2221A-I/SL features (USB-to-UART with GPIO, Industrial RoHS):
- USB 2.0 Full-Speed device (12 Mbps) with bus-powered or self-powered operation.
- USB-to-UART bridge: asynchronous RXD/TXD serial interface for PC↔target communications (baud rates up to about 1 Mbaud commonly supported).
- 4 configurable GPIO pins (GP0–GP3) with direction control and interrupt-on-change capability.
- VIO logic levels: 1.8 V to 3.6 V (allows 3.3 V MCU compatibility); operates from USB power.
- No external crystal required; integrated USB transceiver and controller.
- Software support: drivers and API/library for Windows, macOS, Linux; can enumerate as a virtual COM port (or via API).
- Typical industrial-grade specs: -40 °C to 85 °C operation; -I/SL suffix indicates Industrial, RoHS-compliant, lead-free package.
- Small leadless (SL) package option.
Common applications: USB-to-UART bridge for microcontrollers, data logging, PC-based control/monitoring, and simple GPIO extension.

- Pin count: 14 pins (MCP2221A-I/SL).
- Function: USB-to-UART bridge with two general-purpose I/O pins. It provides USB D+ / D−, VBUS, GND, and UART TXD/RXD plus two configurable GPIOs (GP0, GP1) for simple USB-enabled serial interfaces.

- Manufacturer: Microchip Technology Inc.
- What kind of company: An American multinational semiconductor company that designs, develops, manufactures, and markets embedded ICs (microcontrollers, analog, memory) and connectivity solutions for embedded systems. Headquartered in Chandler, Arizona.

Applications include:
- USB to UART/I2C bridge for microcontrollers, embedded systems, and serial consoles
- I2C master to interface with sensors, EEPROMs, ADC/DAC, and displays from PC or MCU
- GPIO lines for simple control/handshake in instrumentation and test setups
- PC-based data acquisition, lab instruments, and test fixtures
- USB dongles and development tools requiring a USB peripheral interface
- Hobbyist projects and educational kits using a compact USB interface
- Industrial-temperature version (I/SL) suitable for embedded/industrial equipment

The MCP2221A‑I/SL is supplied in a 6‑lead SOT‑23 package (SOT‑23‑6) and is rated for industrial temperature operation (–40°C to +85°C).