| 摘要 |
<p>A pair of emitter connected transistors (1,2) are controlled by field effect transistors (6,7) connected to their respective bases. The common emitter connection is taken through a third transistor (3) to one pole (24) of the supply. In association with a further transistor (4) the former (3) represents a high impedance current source. Common mode signals on the input electrodes (12,13) of the FETs (6,7) thus have no influence. The collectors of the amplifying transistors (1,2) are connected through further transistors (10,11) to the other supply pole (25). These transistors ensure that there is equal current flow through each amplifying transistor, and also act as the output impedance of the amplifier. The output is taken from the common collector connection (2,11) to an output impedance converter circuit (14,15). In most cases phase correction can be made by adjusting the current flow through the transistor (3) in the amplifier emitter leads.</p> |
