| 摘要 |
PURPOSE:To set an arbitrary limiter level, and to obtain a stable limiter output having no temperature characteristic by eliminating an amplitude part exceeding the upper limit side limiter level of an input signal from a first amplifier, by a second amplifier, and eliminating an amplitude part being below the lower limit side limiter level, by a third amplifier. CONSTITUTION:The first amplifier 31 functions as a buffer circuit for allowing an input signal VIN to pass through, and an amplitude part exceeding the upper limit side limiter level of its output signal VOUT is eliminated by the second amplifier 32. Also, in the lower limit side level of the output signal VOUT, an amplitude part being below the lower limit side limiter level is eliminated by the third amplifier 33. As a result, an AC signal having an amplitude determined by the upper limit side and the lower limit side limiter levels can be fetched. Also, the lower limit side and the upper limit side limiter levels VL, VH are set as bias inputs of the second or the third amplifiers 32, 33, therefore, can be regulated arbitrarily by adjusting the bias input. In this way, a desired limiter level VLH is set, and an output signal to which an amplitude limit has been performed by its limiter level VLH is fetched. |
