Wideband amplifier circuit contg. four NPN bipolar transistors - having common base potential and cross-coupled collectors giving large gain bandwidth

摘要

An amplifier circuit for a periodic input signals has four NPN bipolar transistors, minimal frequency response susceptibility to parasitic capacitates and minimal errors caused by the voltage dependency of the individual transistors. It is a monolithic integrated wideband amplifier with a large gain-bandwidth product and a linear gain region. The emitters of the first and fourth transistors (1, 4) from two circuit ports (8, 9). Their collectors form two further ports (12, 13) and are connected to the collectors of second and third emitter-coupled transistors (2, 3). The emitter junction is connected to a fifth port (11) and the base of each emitter-coupled transistor (2, 3) is connected to the base of the transistor (1, 4) whose collector is not connected to it, and via a transistor (5, 6) to a base potential (7) for all four transistors. Several circuits may be cascaded as amplifier stages.