Hello and welcome to The Logic Minute. In this video, we will discuss about the UART communication interface commonly used in personal electronics, industrial and automotive sectors, followed by signal level translation solutions for it.

UART stands for Universal Asynchronous Receiver Transmitter. This is a full duplex two-wire or four-wire signal interface. In the two-wire interface, there is a transmit signal and a receive signal. In the four-wire interface, there are additional care to send and ready to send signals for handshaking control.

The term full duplex means that both transmit and receive data can be done at the same time without a need for any synchronizing clock signal. The UART is an interface with a moderately slow data rate, which is usually measured in baud or bits per second. For example 9,600 baud is 9.6 kbps.

When the two interfacing devices operate at different voltage levels, a translator is required to shift the I/O signal voltage levels to enable the two devices to interoperate.

This is an example of the Programmable Logic Controller, PLC, module used in factory automation application. The digital processing block of the PLC controller module commonly uses the UART interface between FPGA and the ASIC.

AXC4T245 is used for low voltage translation between the FPGA which usually operates at sub 1 baud and the ASIC, usually operating between 1.8 and 3.3 bauds. AXC4T245 belongs to the family of direction controller translation devices that can be configured for your interface level translation. Here dual two-wire UART interface is shown with AXC4T245 device which can be used for four digit level translation.

The TXB is an auto bi-directional translation device which offers the flexibility for voltage translation without the need for separate direction control pins. TXB family provides 20 microamps of DC drift strength making it suitable for interfacing with high impedance loads.

Thank you for watching.