Stmicroelectronics Gmbh

Stmicroelectronics S.a.

G&eacute;rard Bret

Didier Salle

A device for regulating the amplitude of a chrominance signal includes a variable gain amplifier having an input receiving a sub-carrier signal, and an output providing a regulated sub-carrier signal. The gain of the amplifier is controlled by two regulation loops. The first regulation loop operates during the duration of the reference burst. The second regulation loop operates during the visible line. Each of these loops include an up/down counter controlled by a clock. A digital-analog converter has an input receiving the output signals from the first and second up/down counters. An output signal from the digital-analog converter is connected to the gain control of the amplifier. The digital-analog amplifier is controlled by another clock.

Chrominance signal amplitude regulation device

The demodulating device for a chrominance signal includes an oscillator with a controlled frequency, and an adjuster for adjusting the oscillator frequency as a function of a charge voltage of a memory capacitor. The adjuster preferably includes a fine adjustment channel to output a first adjustment value that depends on the charge voltage of the memory capacitor, and a coarse adjustment channel to output a second adjustment value. The second adjustment value is modified when the charge voltage of the memory capacitor is not within a given range. The device is used, for example, in integrated SECAM decoders.

Growing community of inventors

Echirolles, France

Gérard Bret

Growing community of inventors

Echirolles, France

G&eacute;rard Bret

Gérard Bret