Service manual

33
Explanation for circuit operation
7. CRT AMP
The video signal that is first amplified in PGB processor is input to video AMP in approx. 3.5Vp-
p level. TDA111Q used as a video AMP is a 13Mhz band AMP which outputs a video near to
Vdd according to gain control voltage when Vdd is 200V. The following figure shows the internal
block diagram of TDA6111Q.
Block diagram of TDA6111Q
There are two cathode outputs and a independent feedback output. Low input (Vdd) is 12V and
high input (Vddh) is 200V. A peaking circuit is designed in Amp IC input and output part for high
band compensation. The entire output gain is about 34db.