Output voltage correcting circuit for amplifier

Abstract

Abstract PURPOSE:To maintain DC level of output signals or level of low frequency at a specified value by calculating the difference between output signals of positive polarity and output signals of negative polarity and negative feeding back to an amplifier to make calculated difference zero. CONSTITUTION:A difference amplifier 1 consists of an amplifier A, resistors Rf1, Rf2 and a capacitor Cf, and a negative feedback circuit 2 consists of a transistor TR3. A differential amplifier 3 consists of transistors TR1, TR2, resistors Rc1, Rc2 and a constant current power source CC. By such constitution, the difference between output signals VOUT+ of positive polarity and output signals VOUT- of negative polarity is calculated using the difference amplifier 1, and DC bias voltage of the differential amplifier 3 is controlled through the negative feedback circuit 2 to make the difference zero. Thereby, DC level or low frequency level of output signals VOUT+ of positive polarity and output signals VOUT- of negative polarity can be negative feedback controlled to zero level. Accordingly, the capacity of the capacitor C used in the differential amplifier 1 can be made small.

Inventors

• 👤 Toshihiro Yamanaka
• 👤 俊宏 山中
• 👤 Seiichiro Hirayama
• 👤 平山　誠一郎

Bibliographic Details