Overview

The LA7565E and LA7565KM are PAL/NTSC multi-system audio VIF/SIF signal-processing ICs that adopt a minimal-adjustment technique. The VIF circuit adopts a minimal-adjustment technique in which AFT adjustment is made unnecessary by VCO adjustment to simply end product adjustment. The FM detector circuit uses PLL detections to support multi-system audio detection. Since the LA7565BM include an SIF converter on chip, it is easy to implement multi-system audio. In addition, it also includes a buzz canceller that suppresses Nyquist buzz to achieve improved audio quality. The LA7565G and LA7565KM feature improvements over the LA7565B and LA7565BM in the FM low-range frequency characteristics, vertical synchronization buzz, and AFT drift.

特性 Features

? Allows the use of a switch circuit to switch between spilt and intercarrier operation.

? Improved buzz and buzz beat characteristics provided by a PLL detector plus buzz canceller system.

? The IF AGC second filter is built in.

? PAL/NTSC multi-system audio can be implemented easily.

? Adjustment-free circuit design that does not require AFT and SIF coils.

Functions

[VIF Block]

? PLL detector

? AFT

? RF AGC

? Buzz canceller

? Equalizer amplifier

? SIF converter

? VIF amplifier

? IF AGC

[First SIF Block]

? First SIF detector

? First SIF amplifier

[SIF Block]

? PLL type FM detector

? Limiter amplifier