MIL-STD-1553 is a serial multiplex data bus with a transmission speed of 1 megabit per second (Mbps). This speed is equivalent to 1 bit per microsecond. The bus is made up of a shielded twisted-wire pair with an impedance of 70 to 85 ohms at 1 MHz.

Transmitter and receiver devices connect to the bus through isolation transformers. In the most commonly used configuration referred to as transformer coupling, there are also transformers built into the couplers. These couplers provide a physical connection to the bus and stubs.