GENERAL DESCRIPTION
The CMOS digital comb filter circuit is located between video analog-to-digital converters and the video multistandard decoder SAA7151B (not applicable for SAA7191B). The two-dimensional filtering is only appropriate for standard signals from a source with constant phase relationship between subcarrier signal and horizontal frequency. The comb-filter has to be switched off for VTR-signals and for separate VBS and C signals. In VCR and S-Video operation the luminance low-pass and the chrominance bandpass parts can still be used for noise reduction purposes. The processing delay is:
    21 × LL27 clocks in active mode, or 3 × LL27 in short delay bypass mode (BYPS = 1)

FEATURES
• Comb filter circuit for luminance and chrominance separation
• Applicable for standards
    – PAL B/G, M and N
    – PAL 4.43 (525 lines, 60 Hz)
    – NTSC M and N
    – NTSC 4.43 (50 and 60 Hz)
• Luminance and chrominance bypasses with short delay in case of no filtering
• Line-locked system clock; CCIR-compatible
• I2C-bus controlled