TABLE OF CONTENTS Certain basic electronic circuits have proven to be the sources from which many other practical circuit designs have evolved. These basic circuits perform such functions as wave shaping, pulse forming, and signal conversion. Most were originally developed in the receiving-tube era and have been transistorized with either bipolar junction transistors (BJTs) or field-effect transistors (FETs). Many of the circuits described are now available as standard monolithic integrated circuits, and many of these IC packages contain two or more circuits. Some of the circuits described in Sec. 4, "Basic Amplifier and Oscillator Circuits," are also fundamental electronic circuits.
A flip-flop circuit, as shown in the schematic Fig. 5-1, is a two-transistor multivibrator circuit that has two stable states. In one state, transistor Q 1 conducts and transistor Q 2 is cut off. In the other state, transistor Q 1 is cut off and transistor Q 2 conducts. A trigger signal switches the state of the circuit, and the next trigger signal switches it back to the first state. For counting and scaling, a flip-flop can deliver one output pulse for each pair of input pulses. The flip-flop is important because it is the simplest memory circuit. It acts like a toggle switch because when it is set in one state it will remain there until it receives another trigger signal. It is also known as a bistable multivibrator, Eccles Jordan, or trigger circuit. The four useful variations of the basic flip-flop,...
