GENERAL DESCRIPTION
The TDA4686 is a monolithic integrated circuit with a luminance and a colour difference interface for video processing in TV receivers. Its primary function is to process the luminance and colour difference signals from a colour decoder which is equipped e.g. with the multistandard decoder TDA4655 or TDA9160 plus delay line TDA4661 and the Picture Signal Improvement (PSI) IC, TDA467X, or from a feature module.
FEATURES
⢠Intended for double line frequency application (100/120 Hz)
⢠Operates from an 8 V DC supply
⢠Black level clamping of the colour difference, luminance and RGB input signals with coupling-capacitor DC level storage
⢠Two analog RGB inputs, selected either by fast switch signals or via I2C-bus; brightness and contrast control of both RGB inputs
⢠Saturation, contrast, brightness and white adjustment via I2C-bus
⢠Same RGB output black levels for Y/CD and RGB input signals
⢠Timing pulse generation from either a 2 or 3-level sandcastle pulse for clamping, vertical synchronization and cut-off timing pulses
⢠Automatic cut-off control or clamped output selectable via I2C-bus
⢠Automatic cut-off control with picture tube leakage current compensation
⢠Cut-off measurement pulses after end of the vertical blanking pulse or end of an extra vertical flyback pulse
⢠Increased RGB signal bandwidths
⢠Two switch-on delays to prevent discolouration before steady-state operation
⢠Average beam current and peak drive limiting
⢠PAL/SECAM or NTSC matrix selection via I2C-bus
⢠Emitter-follower RGB output stages to drive the video output stages
⢠I2C-bus controlled DC output e.g. for hue-adjust of NTSC (multistandard) decoders
⢠No delay of clamping pulse
⢠Large luminance, colour difference and RGB bandwidth.
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