视频信号的箝位、偏置和交流耦合

视频信号的箝位、偏置和交流耦合Get A Grip On Clamps, Bias and AC-Coupled
Video Signals
This article explains clamps, bias, and AC-coupled video signals, the
appropriate signals for each, the merits and drawbacks of dual and single
power supplies, and why some circuits are inherently better for some
applications.
Why should you AC-couple your video signals?
If you haven't asked this question, you should. If the reason is government mandate, customer
specification, or industry protocol, you're probably doing the right thing! In many cases, it's
because the application has a single supply, and you feel that you must AC-couple. Maybe you
still have dual supplies, because going to a single supply will involve AC-coupling the video,
which will compromise the video quality.