Television character multiplex data slice circuit

Abstract

Abstract PURPOSE:To improve remarkably the accuracy of a reference level of a data slice by adopting the circuit constitution where a constant voltage circuit whose output is overridden to a clamp potential and an analog switch is added. CONSTITUTION:After a TV video signal on which character multiplex data and applied to an input terminal IN is amplified at an amplifier AMP, the result is inputted to a clamp circuit CLC, where the signal is clamped so that the pedestal level of the TV video signal is at the same DC level as a potential of the 1st reference voltage source Vref1. On the other hand, a voltage overridden on the 1st reference voltage source Vref1 by the 2nd reference voltage Vref2 is precharged to a sample/hold capacitor C3 via the 2nd analog switch SW2. The reference potential of the data slice is decided by sample and hold the average value of the pulse of a clock line with a clock line filter circuit CLF comprising a resistor R, a coil L and a capacitor C1 to the capacitor C3 via the 1st analog switch SW1.

Inventors

• 👤 Kinya Taguchi
• 👤 田口　欽也

Bibliographic Details