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1 color low-pass filter – Texas Instruments TVP5147M1PFP User Manual

Page 20

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Functional Description

12

SLES140A—March 2007

TVP5147M1PFP

Line

Delay

Peaking

NTSC/PAL

Remodulation

NTSC/PAL

Demodulation

Notch

Filter

Color LPF

2

5-Line

Adaptive

Comb

Filter

Notch

Filter

Notch

Filter

Notch

Filter

Contrast

Brightness

Saturation

Adjust

Cr

Y

Cb

Y

Burst

Accumulator

(U)

U

SECAM

Color

Demodulation

V

Delay

CVBS/Y

SECAM Luma

CVBS

CVBS/C

Color LPF

2

Burst

Accumulator

(V)

U

V

Delay

Delay

Figure 2−3. Composite and S-Video Processing Block Diagram

2.2.2.1

Color Low-Pass Filter

High filter bandwidth preserves sharp color transitions and produces crisp color boundaries. However, for
nonstandard video sources that have asymmetrical U and V side bands, it is desirable to limit the filter
bandwidth to avoid UV crosstalk. The color low-pass filter bandwidth is programmable to enable one of the
three notch filters. Figure 2−4 and Figure 2−5 represent the frequency responses of the wideband color
low-pass filters.