| 摘要 |
PURPOSE:To obtain excellent accuracy, frequency characteristic and distortion characteristic by adopting a feedback type utilizing a differential amplifier for a limiter circuit and employing a transistor(TR) to constitute its feedback circuit. CONSTITUTION:The feedback type limiter circuit consists of a differential amplifier 1 and a feedback TR 3 for limiter. Then the TR 3 for limiter is completely turned off in the region where no limiter is applied. Thus, the original signal is not distorted and the deterioration in the frequency characteristic is not caused. Since the difference from a setting voltage is compressed to a fraction of loop gain of the feedback circuit in the limiter region, it is possible to apply limiting up to a high frequency when a high gain is applied to the feedback circuit at a broad band. Thus, the limiter circuit with excellent accuracy, distortion characteristic and frequency characteristic is obtained as a simple circuit against a signal with a small amplitude and a wide band such as a picture signal. |
