Isolated Dual Channel USB/Serial Adaptor

with adjustable signal levels



The USB/Serial Adaptor provides two virtual serial interfaces (UARTs) at a personal computer. The UART signals has TTL levels (2.5 - 5.5V) and therefore a direct communication with microcontrollers is possible. The level can be setup by a switch, either 3.3V, 5V or a variable level (2.5 - 5.5V), determined by the supply voltage of a connected circuit. Both UART interfaces are isolated against the USB connector. Each UART interface provides a data output (TxD), input (RxD) and also a handshake output and input. Usually RTS and CTS are set as handshake lines, but can be changed to DTR and DSR by jumpers inside the device. All connectors are protected against ESD and short circuit.

The device is based on the USB/serial interface circuit FT2232H by Future Technology Ltd. (FTDI). This circuit is connected with "USB High Speed" (480MBit/s) to the PC, therefor low latency times are offered and baud rates up to 12MBaud are possible! FTDI offers very powerful and flexible drivers. They are available for "Microsoft Windows", "Apple MacOS", "Linux" and other operating systems.

Characteristics Overview:

Additional Information:

Technical Specification

Supply voltage 4.75 - 5.25V=; typ. 5.0V= supplied over the USB interface
Current consumption approx. 110mA  
UART channels 2 with common ground and supply, isolated against USB
UART connections (each channel) RxD, TxD, RTS*, CTS* *) changeable to DTR and DSR by jumpers (casing has to be opened to do this)
Signal output resistance typ. 150Ω short circuit and ESD protected
Signal input level -0.5 - 5.5V max. 50V
UART signal level (internal supply voltage) 3.3V (3%) / 5.0V (3%) / 2.45V - 5.5V the variable signal level is determined by the control voltage at pin "Vext"
Input resistance of Vext connection 100kΩ 1% will drop to 11kΩ if input voltage exceeds specification
Voltage at Vext input 2.45 - 5.5V max. 50V
Isolation voltage 100V (max. 500V) between UART and USB respectively casing
Operation temperature 0 - 70C max. 90% relative air humidity, not condensing
Storage temperature -25 - 75C  

Products and Prices

The product is available a fully assembled and checked device. The scope of delivery contains the device only without any accessory.

Price: Euro 89.00 incl. VAT, plus shipment costs (category C)

Order No.: USIIV

How to order and pay

You can order via E-Mail or FAX. Please give Your invoice and delivery address.

Order by E-Mail:
Order by FAX: +49-7541-81483

Delivery is only possible by prepayment! You will get a preliminary invoice as PDF file via E-Mail, which contains bank transfer and Paypal information. After payment the goods will be delivered.

We apologize, that we can't offer you a more comfortable way for order and payment in the moment.

More informationen about order and payment...


The following files are available for download.

Instruction manual revision 1.1 USIIV_Rev11_Manual.pdf 160kByte


On the web pages, linked below, you will find the drivers for the device. Hint: If you still use a device with a FTDI chip inside, most likely a driver installation is not necessary.

VCP driver (virtual COM port)
D2XX driver (direct access and usage of special functions)