after processing, the restored digital signals are retrieved. If the TV circuit can tell the difference between a 1 and a 0 ( the basic digital code), the video and audio signals can be applied to the picture tube/ loudspeakers exactly as they appear at the tuner output. As a point of reference, the picture/sound performance of a digital TV is about the same as compact disc performance when compared to audio tapes and LPs. A digital television set can easily be adapted for the three basic TV broadcast systems. This is because the sampling clock for the A/D converter is phase locked to the broadcast colorburst frequency. Simply by changing the frequency of the clock, the system can accommodate different TV broadcast system like NTSC (3.58 MHz) or PAL (4.43 MHz) colorburst frequencies.In many cases, there are no coupling components between circuits in digital TV. This mean that there are no capacitor, inductor, or RC circuits to break down or to distort audio/video signals. generally, all connections between ICs in digital TV are made directly through wires or wire buses.The digital signal processing is controlled by phase-locked loop (PLLs), providing much more accurate control. For example, TV sync checked against broadcast sync on every horizontal line.Since the TV picture can be stored in digital form, a digital TV can reduced flickerZ caused by interlaced scanning and can increase the apparent resolution of the picture. Digital TV eliminates interlace by storing all 525 lines and then displaying the complete picture on the screen all at once ( instead of having only half the total scan lines on the screen for each field of video, as is the case for analog or conventional TV.Noise-reduction circuit and echo-canceling systems are included in some digital TV systems. this feature provide superior picture quality for viewers in weak-signal area, or broadcast areas where are excessive ghostsZZ. In addition findings to the superior p...
