The Fascinating Transistor-transistor Logic (TTL) Clock!

Before you involved yourself into this TTL clock development project, you should know some of the fact and history of the TTL, so you will knew it better!

Transistor-transistor Logic or also known as ‘TTL’ is a class of digital circuits, which it is built from bipolar junction transistor (BJT) and resistor as well. The reason why it is given the name ‘TTL’ because both the logic gating functions and the amplifying function are fully performed by transistors!


In addition, TTL is also a widespread integrated circuit (IC) family, which is can be used in a very wide range of applications. The TTL can be found in the computer, industrial controls, consumer electronics, test equipment and so on.

According to the history, the TTL logic was invented by James L. Buie in 1961 and the very first commercial Integrated circuit TTL devices were been manufactured by Sylvania in 1963.

Ok, for the today TTL clock project, you’ll need to experience yourself with the 74LSxx series TTL-chips, which is smaller and more compact than other TTL-chips. Thus, you can only find very few discrete components, but are mostly filter caps and resistors on this 74LSxx series TTL-chips!

Oh, you just need to ensure that you didn’t get confused with the 74LS74 and 74LS47, as the pin counts for both of the TTL-chips are significantly different! [read]

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