Emitter-coupled multivibrator having frequency proportional to control voltage

摘要

An emitter-coupled multivibrator includes two transistors, a base potential supplying circuit for maintaining the base potential of one transistor which is on at a high potential and the base potential of the other transistor which is off at a low potential, and a base potential control circuit for controlling the base potential of the transistor which is on in accordance with a frequency controlling voltage V.sub.C. A coupling capacitor is charged with a constant current which flows through the transistor which is on, and when the voltage between the base and the emitter of the transistor which is off reaches a predetermined value by charging, the transistor which is off is turned on, while the transistor which is on is turned off. The same operation is repeated so as to alternately turn on and off the transistors for the purpose of oscillating operation. At the same time, the base potential control circuit controls the base potential of the transistor which is on in accordance with the frequency controlling voltage V.sub.C, thereby alternately turning on and off the transistors at a frequency f.sub.0 which is proportional to the frequency controlling voltage V.sub.C.