| 摘要 |
PURPOSE:To effectively perform switching, by driving at least one differential amplifier with selective control, out of a plurality of differential amplifiers. CONSTITUTION:A differential amplifier DA1 consists of differential amplifying transistors (TR)Q1, Q2 and diodes Q8, Q9 and a differential amplifier DA2 consists of differential TRs Q3, Q4 and diodes Q10, Q11, and TRs Q5, Q6 form current mirror circuits flowing the same current to the TRs Q1, Q2 and Q3, Q4. The amplifiers DA1, DA2 are driven with the switching selection control of a switch SW. Thus, the crosstalk between input signals inputted to each differential amplifier can be limited sufficiently small, allowing to obtain an output with good distortion factor. |
