correction to "The NOT Gate"

Thread Starter


Joined May 5, 2010
I believe Volume 4 Chapter 3 The NOT Gate s/b "This circuit is composed exclusively of resistors, diodes and bipolar transistors." instead of

"This circuit is composed exclusively of resistors and bipolar transistors."

Good site...



Joined Mar 24, 2008

Shown here is a schematic diagram for a real inverter circuit, complete with all necessary components for efficient and reliable operation:

This circuit is composed exclusively of resistors and bipolar transistors. Bear in mind that other circuit designs are capable of performing the NOT gate function, including designs substituting field-effect transistors for bipolar (discussed later in this chapter).
Good call.

This is a TTL gate. A RTL gate would be a bit different. A TTL gate can be built without diodes, but since the author chose to use this schematic it is a false claim. D1 isn't really needed, and R4, Q3, D2, and Q4 is a classic TTL totem pole output, fairly standard on most TTL gates.
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