The transistor-transistor logic (TTL) type integrated circuits offer excellent performance due to the following characteristics: In other words, simple gates and flip–flops, various shift registers being used in computers, and microprocessors slice chip bits are manufactured on lines of the TTL family. Remember that this family comprises (SSI circuit series) simple gates and flip–flops, (MSI circuit series) various shift registers being used in computers (LSI series) microprocessor bit-slice chips, and a very broad selection of circuit modules. As a result of this, the circuit speed increases due to a reduction in the rising and falling times of the circuit. Moreover, as a result of a smaller multi-emitter transistor area as compared to a diode, low capacitance generates on substrate. As a multi-emitter transistor is quite smaller in size as compared to a diode, therefore the size of the wafer (on which this transistor is mounted) becomes larger, which is thus, brought into use in a far better way. Therefore, instead of using a number of diodes on a DTL circuit input, only one multi-emitter transistor is mounted on TTL circuit, hence TTL occupies far less space as compared to a DTL circuit. The greatest advantage of a TTL circuit is that a multi-emitter transistor is used on its input and the number of transistors emitters is equal to the circuits’ fan–in. 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.

Totem pole output driver