| 摘要 |
PURPOSE:To attain ease of circuit integration and to decrease variance in the characteristic by providing a high pass-filter and a low-pass filter using in common an subtractor and at least one element, applying a signal to both the filters, amplifying the signals by an exclusive amplifier respectively and subtracting them by the subtractor. CONSTITUTION:The signal is fed to the low-pass filter comprising a base of a transistor (TR)8, and a resistor 20 and a capacitor 27, and then to a base of TRs 9, 10. The TRs 8, 9 form a differential amplifier, which applies a high frequency component being a difference between the input signal and a low frequency component to a base of a TR12 in opposite phase to the input signal. Further, TRs 10, 11 form a differential amplifier, the lower frequency component of the input signals is amplified and fed to a base of the TR12 in phase to the input signal. Thus, since the phase compensating characteristic is set by an externally mounted resistor 20 and capacitor 27, the variance in the characteristic is less, the limitation of the setting frequency is less and the degree of freedom of the characteristic setting is increased. |
