| 摘要 |
PURPOSE:To attain accurate 90 deg. phase shift by connecting a phase delay compensating circuit comprising a level adjusting resistor and the 2nd common base transistor (TR) to the input of a phase shift circuit not at the side of a common base TR of a differential amplifier of the post-stage. CONSTITUTION:An output of a common collector TRQGC is fed to a phase shift capacitor CHS and to the common base TRQC through a level adjusting resistor RLA. In this case, the emitter potential of the common collector TRQGC and that of the common base TRQC are made equal so as not to flow a bias current to the level adjusting resistor RLA, then the emitter current of the common base TRs QC, QGB is made equal and the current from a constant current source comprising TRs Q3, Q4 is made equal, then the input to a differential amplifier DA due to temperature drift is not unbalanced.
|
