| 摘要 |
PURPOSE:To widen the input dynamic range by suppressing the fluctuation of the input operating potential at an amplifier by providing the 1st and 2nd transistors (TR) whose base/emitter current paths are connected in anti-parallel between an inverting and a non-inverting input of an amplifier. CONSTITUTION:When a signal representing that a potential difference between the inverting input terminal 2 and the non-inverting input terminal 3 of the amplifier 1 is lower than the base-emitter voltage VBE of the 1st and 2nd TRs 11, 12 is impressed between the inverting and non-inverting inputs 7, 8, the input clamp circuit is not operated, the amplifier 1 is operated depending on the difference voltage between the input voltage VIN impressed to the inverting input 7 and the reference voltage Vref impressed to the non-inverting input 8 and the result is outputted at an output terminal 4. On the other hand, when a signal representing that the potential difference between the inverting input terminal 2 and the non-inverting input terminal 3 of the amplifier 1 is higher than the base-emitter voltage VBE of the 1st TRs 11, 12 is impressed between the inverting and non-inverting terminals 7, 8 the clamp circuit is operated. The input power potential of the amplifier 1 is nearly the same as the input operation potential when the clamp circuit is not operated to suppress the fluctuation. |
