CIRCUIT FOR SEPARATING VERTICAL SYNCHRONOUS SIGNAL FROM COMPOSITE SYNCHRONOUS SIGNAL

摘要

PURPOSE: A vertical sync dividing circuit is to stably divide a vertical sync signal from a combined sync signal containing a horizontal sync signal, an equalized signal, and a vertical sync signal. CONSTITUTION: An input unit(10) receives a combined sync signal(110) containing a horizontal sync signal and a vertical sync signal from an input terminal(103) to provide a control current(123). A constant current unit(200) receives the control current to provide a constant difference current(210). A comparing unit(300) receives the different current and a comparing reference voltage to provide a compared current(310) and the difference current. A condenser(400) receives the difference current to provide a voltage which is charged and discharged through a capacitor(C1). An output unit(500) receives the compared current to output the compared reference voltage and a vertical sync signal divided from the combined sync signal.