Overview
The LA7566 is a VIF/SIF IC that supports PAL and NTSC multisound and that adopts a semi-adjustment-free system. To simplify adjustment, the VIF block adopts a technique in which AFT adjustment is no longer required by VCO adjustment. The SIF block supports audio multidetection by adopting a PLL detection technique. The SIF block provides 4 inputs with IC internal switching for easy design of multi-sound systems. Additionally, these switches can also be used for video system sound trap switching. The LA7566 also includes a buzz canceller that suppresses Nyquist buzz to achieve improved audio quality.

FEATUREs
• No coils are used in the AFT and SIF blocks, making these circuits adjustment free.
• PAL / NTSC multisound system can be constructed easily.
• Built-in buzz canceller for excellent audio performance

Functions
[VIF Block]
    • VIF amplifier • PLL detector • BNC • RF AGC
    • EQ amplifier • AFT • IF AGC • Buzz canceller
[First SIF Block]
    • First SIF amplifier • First SIF detector • AGC
[SIF Block]
    • Multiple input switch • Limiter amplifier • PLL FM detector