Automatic gain control circuit

Details Automatic gain control circuit Automatic gain control circuit

1985-06-18

1987-04-14

Masinick, Michael A.

Facsimile and static presentation processing

Facsimile

Specific signal processing circuitry

358176, H04N 552

Patent

active

046582975

ABSTRACT:
An automatic gain control (AGC) circuit 30 includes a pulse mixing circuit 31 for mixing a reference pulse P having a specified amplitude in a pedestal of a composite video signal with a sync-tip level of a synchronizing signal clamped. Based on the reference pulse P, keyed AGC operation is performed preferentially and peak AGC operation based on detection of the peak of a video signal V is performed as required. According to the change of reference voltage by a variable resistor VR for setting of an AGC operation level, electric currents I.sub.2 and I.sub.1 flowing in mirror circuits Q.sub.11 and Q.sub.4 change. As a result, the amplitude of the reference pulse P changes in proportion to the change of the reference voltage. Thus, a wide range of effective output gain can be applied.

REFERENCES:
patent: 3249695 (1966-05-01), Loughlin et al.
patent: 4121252 (1978-10-01), Saiki et al.
patent: 4149190 (1979-04-01), Wessler et al.
"Monolithic ICs for Video Processing Circuit", by Norio Meki et al, National Technical Report, vol. 25, No. 1, published Feb. 1979, pp. 102-106.

Affiliated with

Also associated with

Rating

Automatic gain control circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Automatic gain control circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic gain control circuit will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1789538