Isolated Serial to USB Converter

Isolated Serial to USB Converter - Simplifies interfacing MCU/PLD/FPGA-based designs to a PC via USB port

Isolated Serial to USB Converter


The Isolated Serial to USB Converter—D5055 allows easy interfacing between the serial port on MCU/PLD/FPGA-based designs and a Windows, Mac, or Linux PC. Standard USB 2.0 and serial interfaces make it immediately usable in most engineering environments. The D5055 enables simple, real-time communication and interaction with microprocessor-based circuits under development and during operation.

The converter is powered via the mini USB-B connector. The optically-isolated serial port interface circuitry can be powered from the target device, thus eliminating the need for additional power supplies in the test setup. Optionally, it can be externally powered to eliminate drain from low power circuits.


  • Simplifies interfacing MCU/PLD/FPGA-based designs to a PC via USB port.
  • Optical isolation prevents ground loop problems.
  • Self-powered interface requires no additional power supplies.
  • 3V to 5V operation.
  • Eliminates need for RS-232 port, allowing user to employ laptops.
  • LEDs indicate USB and Target power, Tx/Rx activity.
  • Tx/Rx paths can be swapped for crossover requirements.
  • Allows use of standard terminal programs, including TeraTerm, HyperTerminal, Xterm, and PuTTY.


Isolated Serial to USB diagram

Key Specifications

  • Drivers available for Windows 7 (32&64 bit), Vista, XP (32&64 bit), 98, Mac OS, OSX, Linux 2.4 & up.
  • USB 2.0 via mini USB-B connector.
  • Serial port capability:
         o 300 to 3M baud
         o 7 or 8 data bits, odd or even parity
         o 1 or 2 stop bits
         o odd/even/mark/space or no parity
         o X-On, X-Off, HW handshaking