GENERAL DESCRIPTION
The TDA4651 is a monolithic integrated multistandard colour decoder for PAL, SECAM and NTSC (3.58 and 4.43 MHz) with negative colour difference output signals. The colour difference output signals are fed to the TDA4661, switched capacitor delay line.

FEATURES
Identifies and demodulates PAL, SECAM, NTSC 3.58 and NTSC 4.43 chrominance signals with:
• Gain controlled chrominance amplifier
• ACC demodulation controlled by system scanning
• Internal colour difference signal output filters to remove the residual subcarrier
• PAL / NTSC demodulation
    – H (burst) and V blanking
    – PAL switch (disabled for NTSC)
    – NTSC phase shift (disabled for PAL)
    – PLL-controlled reference oscillator
    – two reference oscillator crystals on separate pins with automatic switching
    – quadrature demodulator with subcarrier reference
• SECAM demodulation
    – limiter amplifier
    – quadrature demodulator with a single external reference tuned circuit
    – alternate line blanking, H and V blanking
    – de-emphasis
• Identification
    – automatic standard identification by sequential inquiry
    – secure SECAM identification at 50 Hz only, with PAL priority
    – four switched outputs for chrominance filter selection and display control
    – external service switch for oscillator adjustment