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TTL(3v3) to USB converter cable

A fast simple way to connect devices with a 3.3 volt TTL serial interface to USB

A TTL level serial interface to USB converter cable, for connecting serial data at 3V3 logic levels to a computer USB port. Includes connections for RTS and CTS control lines.

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  • Enables an application program to receive and transmit serial data from and to a device operating at 3.3 volt TTL logic levels
  • The drivers provided make the PC USB port appear as a standard serial port, i.e. it will appear to application programs as "COM3" or "COM4" etc.
  • Ideal for test and development - TTL connections terminated with easy to connect female receptacles suitable for pushing onto standard 0.64 mm (0.025 inch) square PCB header pins

Typical Application


Technical summary (see data sheet for further details)

Speeds (baud rate)

Supports any speed in the range 300 bps to 3Mbps, i.e. includes non-standard speeds. Automatically configures itself to the speed set by the PC application.  


7 or 8 bits (excluding parity), with 1 or 2 stop bits


Handles odd, even, mark, space or no parity


256 byte receive buffer and 128 byte transmit buffer utilizing buffer smoothing technology to facilitate high data throughput

PC driver software

Supplied with Microsoft WHQL certified drivers for Windows 98, ME, 2000, Server 2003, XP and XPx64
Drivers for MAC OS, Linux, and Windows CE available online

USB connection

Compatible with ports to standard 1.1 or 2.0

TTL connections

Six connections provided:TXD, RXD, RTS, CTS, GND, Vcc (5.0V)
All terminated with female receptacles suitable for pushing onto standard 0.64 mm (0.025 inch) square PCB header pins

Power supply The USB cable includes hardware built into its USB connector (the advanced FTDI FT232RQ i.c.). This is powered from the USB port it is plugged into, so no external supply is needed
Cable length 1.8 metres (6 feet)
Operating and storage

The cable is designed for dry indoor use and storage only. The operational ambient temperature range is -40 to +85 degrees C. (i.e. suitable for automotive and industrial environments)


CE and FCC approved

Further technical information

Data Sheet (216KB) >>

Installation and Operating Instructions (547KB) >>


What's included

TTL(3V3) to USB converter cable, drivers & documentation on CD, printed 30 page installation & operating instruction booklet, 12 months warranty, lifetime support by phone or email
Order code:  TTL(3V3)-USB 25.90 + VAT (UK) Lead time: two weeks  Order now

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                       New Forest Electronics Tel. +44 (0) 1425 650089                 Issue 3.108    12 March 2024