FT231XS-U

Controllers Overview

The FT231XS-U is a USB to UART bridge IC manufactured by FTDI, designed for single-channel asynchronous serial data transfer. It integrates a full USB 2.0 controller and handles the entire USB protocol internally, eliminating the need for specific firmware programming. The device supports data transfer rates from 300 baud to 3 MBd at TTL levels. It features a 512-byte receive buffer and a 512-byte transmit buffer utilizing buffer smoothing technology. The chip includes 2048 bytes of multi-time programmable (MTP) memory for storing device descriptors and CBUS I/O configurations. It operates on a supply voltage of 3.3V to 5V with a typical supply current of 8mA. The component is housed in a 20-SSOP package with a width of 3.90mm and functions within an operating temperature range of -40°C to 85°C.

Controllers Feature Summary

• Integrates complete USB 2.0 protocol handling without requiring external firmware or crystals.
• Includes configurable CBUS I/O pins and dedicated transmit/receive LED drive signals.
• Supports flexible UART configurations including 7/8 data bits, 1/2 stop bits, and various parity options.
• Features built-in battery charger detection allowing high-current charging without device enumeration.

Controllers Applications

• USB to UART interface conversion for embedded systems
• Evaluation of battery charging features in portable devices
• Glue-less interface connections to external microcontrollers or FPGAs

Controllers Procurement Notes

Verify the exact suffix against official datasheets to confirm package type and electrical characteristics. Ensure compatibility with required operating temperatures and voltage levels. Confirm RoHS compliance status if environmental regulations apply. Check for specific MTP memory pre-programming requirements regarding VID/PID and serial numbers.

Controllers Selection Notes

Select this component when a compact, single-channel USB-to-UART solution is required without external clock components. Consider the 20-SSOP package constraints for PCB layout. Evaluate the 512-byte FIFO depth against throughput requirements. Verify that the 3.3V to 5V supply range matches the system power architecture.

Controllers Part Context

The FT231XS-U belongs to the FT-X series and X-Chip family from FTDI. It is part of the USBmadeEZ-UART line, focusing on simplified integration for USB-to-serial applications. This model serves as a bridge between USB hosts and asynchronous serial peripherals, replacing older discrete solutions.

Controllers Replacement Considerations

FT231XQ-T: Alternative QFN EP package variant with similar electrical specifications.

Controllers FAQ

Does the FT231XS-U require an external crystal oscillator?

No, the device features fully integrated clock generation and does not require an external crystal.

What is the maximum supported baud rate?

The maximum data transfer rate is 3 MBd for RS422, RS485, and RS232 interfaces at TTL levels.

Can the CBUS pins be configured for custom functions?

Yes, the CBUS I/O pins are configurable via the internal MTP memory to suit specific application needs.