TRANSISTOR CIRCUIT

摘要

PURPOSE:To determine desired frequency characteristics and to solve problems when a filter is fitted outside by setting the emitter current level of an emitter follower transistor (Tr) whose output is connected to a trailing stage circuit to a specific value. CONSTITUTION:A current i1 flowing to a Tr6 when a voltage Ve is varied by varying the value of a variable resistance R is Ve/R1 and a current ie flowing to Tr7 is Ve/R2. Then, an interval resistance re' including the emitter follower Tr4-0 is represented as {1 + (number of diodes)} X 26/ie and adjusted by selecting the value of the resistance R. Thus, the value of the resistance R is selected to obtain desired frequency characteristics.