This circuit has vastly been in use since 1970 due to its high speed, better fan–in and fan–out, simple use, and an easy interfacing features (a process in which the output of two or more than two devices is interconnected with the input of another device so that combined together they could work according to our will and needs, is called interfacing). In other words, a logic circuit, the input, and output of which consists on just transistors, is called a TTL circuit.

Transistor – transistor logic circuit is a logic circuit, in which instead of fitting diodes on inputs (as is done in DTL circuits), multi- emitter transistor (a transistor which has two or more than two emitters, is known as multi- emitter transistor) has been mounted. Transistor-transistor logic (TTL) is the most popular and widely used family of digital devices, which was introduced by Texas Instruments in 1964. Transistor -Transistor Logic Circuit – TTL Circuit Advantages of Totem Pole Output Circuit.Major Types of Output Circuits for TTL Gates.When Both Inputs or Either Input is low.Transistor -Transistor Logic Circuit – TTL Circuit.