Method and apparatus providing high speed video signal limiting

摘要

An input signal (IN) and a threshold signal (Vt) are coupled to an output terminal (2) via the base-emitter paths of first (Q1) and second (Q2) transistors having respective collector electrodes connected to a supply voltage source (3). The output terminal (2) is coupled to a source of reference potential (4) via a first resistor (Re) and is coupled via a second resistor (Rd) to a selected plate of a capacitor (C1) that is connected between the collector and base electrodes of the second transistor (Q2). Circuit impedances are scaled such that ReRdR1 wherein Re and Rd are the values of the first and second resistors, respectively, and R1 is a component of the output impedance of the threshold signal source (5).