Clamping circuit with wide input dynamic range for video or other AC coupled signals

A clamping circuit having an input node, an output node, and a power supply, comprising:

• a clamping capacitor coupled to the input node, the input node coupled to receive a video input signal;
• an automatic clamping circuit portion coupled to the clamping capacitor to automatically clamp the synchronization pulse of the video input signal to a first predetermined reference voltage of a first clamping pulse signal;
• a customizable clamping circuit portion coupled to the automatic clamping portion to clamp any portion of the video input signal to a second predetermined reference voltage of a second clamping pulse signal;
• and
• a buffer coupled between to the customizable clamping circuit portion and the output node,
• wherein the automatic clamping circuit portion comprises:
• a comparator having a first and second input, and an output;
• a first level shift circuit coupled between the first input of the comparator and a reference voltage input;
• a second level shift circuit coupled between the second input of the comparator and the clamping capacitor;
• a first transistor, having a gate, a drain, and a source, the gate coupled to the output of the comparator, the source coupled to the power supply, the drain coupled to the clamping capacitor;
• and
• a current source coupled between the clamping capacitor and ground.