| 摘要 |
PURPOSE:To reduce the offset voltage at the single-ended push-pull amplifier, by providing the current source circuit in which the current changes with the offset voltage. CONSTITUTION:The signal from the input terminal IN is output via the SEPP amplifier consisting of FETQ, transistors TRQ2, TRQ3, Q4. TRsQ5, Q6 and Q7, Q8 form respectively the current Miller circuit and also the constant current circuit, and TRsQ5, Q7 are in cascode connection between the power supplies of positive and negative polarity. Accordingly, when the offset is shifted, the collector current of TRsQ6 or Q8 changes with the offset voltage, allowing the offset voltage at about ground potential. Thus, even if a FET is used at the first stage, the offset voltage can always be at ground voltage. |
