Integrated circuit producing signals for modulation display - has preamplifier with differential transistor input stage with dynamic load

摘要

The integrated circuit is for generating signals for a modulation display and contains a preamplifier connected to a bias voltage source and a rectifier with two complementary transistors (5,6). It ensures a high degree of sensitivity, linearity and reproducibility of electrical data. It may be used in 'Hi-Fi' magnetic tape equipment. The preamplifier (4) input stage differential transistors (20,21) are of pnp type and have a dynamic load in the form of transistors (22,23). It contains a current source and an intermediate stage with two npn transistors (24,25) in a Darlington pair. The second transistor (2,5) of the Darlington pair has a dynamic collector load. The rectifier transistors (5,6) have commoned emitters which are also connected to the intermediate stage input via a feedback resistor and balancing capacitor and to the modulation display.