GENERAL DESCRIPTION
The TDA4661 is an integrated baseband delay line circuit with one line delay. It is suitable for decoders with colour-difference signal outputs ±(R−Y) and ±(B−Y).

FEATURES
• Two comb filters, using the switched-capacitor technique, for one line delay time (64 µs)
• Adjustment-free application
• No crosstalk between SECAM colour carriers (diaphoty)
• Handles negative or positive colour-difference input signals
• Clamping of AC-coupled input signals (±(R−Y) and ±(B−Y))
• VCO without external components
• 3 MHz internal clock signal derived from a 6 MHz CCO, line-locked by the sandcastle pulse (64 µs line)
• Sample-and-hold circuits and low-pass filters to suppress the 3 MHz clock signal
• Addition of delayed and non-delayed output signals
• Output buffer amplifiers
• Comb filtering functions for NTSC colour-difference signals to suppress cross-colour.