# SN761678 TV/VCR Tuner

## Overview
This document details the SN761678, a single-chip synthesized tuner IC designed for TV/VCR tuning systems. It includes a PLL synthesizer, 3-band local oscillators, mixer, tuning amplifier, and band switch drivers.

## Key Features
️· Functionality: Combines PLL synthesizer, local oscillators, mixer, amplifier, and band switch drivers.
️· I2C Interface: Supports serial communication for control and data transfer.
️· Frequency Range: Designed for VHF and UHF signals.
️· Power Supply: Requires a 5V supply voltage (VCC).

## Electrical Characteristics
️· Supply Voltage (VCC): 4.5 to 5.5 V
️· Current Consumption (Icc): 60mA (typical)
️· Operating Temperature: -20 to 85°C
️· Oscillator Frequency: Crystal oscillator frequency = 4 MHz

## Pin Descriptions (Selected)
️· VCC: +5V Power Supply
️· GND: Ground

️· XTAL: 4 MHz Crystal Oscillator Input
️· SDA: I2C Serial Data
️· SCL: I2C Serial Clock
️· RF IN: VHF/UHF RF Input
️· IF OUT: Intermediate Frequency Output

## I2C Communication
️· Addressing: Controlled via I2C interface.
️· Data Transfer: Supports both write and read modes.

## Functional Blocks
️· PLL Synthesizer: Generates local oscillator signals.
️· Local Oscillators: Provides signals for VHF and UHF ranges.
️· Mixer: Mixes RF signals with local oscillator signals.
️· IF Amplifier: Amplifies the intermediate frequency signal.
️· Band Switch Drivers: Selects the appropriate frequency range.