| 摘要 |
<p>PURPOSE:To miniaturize the circuit by supplying a control signal outputted from a clamp control circuit making feedback clamping to the termination resistor at the output terminal of a low pass filter so as to decrease a DC current flowing to the low pass filter. CONSTITUTION:A clamp control circuit 14 receives a clamp pulse Pc fed to an input terminal 3 and a video signal from a buffer amplifier circuit 13 and supplies a control signal Sc in response to the pedestal level of the video signal to an amplifier circuit 11 to act like a so-called feedback clamping circuit. The control signal Sc outputted from the clamp control circuit 14 is fed to a termination resistor 17 of a low pass filter 12 is a buffer amplifier circuit 16. Thus, a DC level difference between the input terminal and the output terminal of the low pass filter 12 is cancelled and a DC component flowing through the low pass filter 12 is reduced. Thus, distortion due to DC magnetization is not caused in a coil being a component of the low pass filter so that a small sized coil is used for the purpose.</p> |
