TEA0678

Notes
1. The device may not operate correctly when subjected to these ratings when the ratings exceed the electrical characteristics of the device as specified in Chapter "Characteristics". The device will recover automatically when the environment is reduced to the requirements of the characteristics.
2. The TEA0678 allows a HIGH-level at switching pins without supply voltage (V_CC = 0; stand-by mode). This means a maximum input voltage of 6.5 V for the switching input pins.
3. Human body model (1.5 k, 100 pF).
4. Machine model (0 , 200 pF).

The TEA0678 is a bipolar integrated circuit that provides two channels of Dolby B noise reduction for playback applications in car radios. It includes head and equalization amplifiers with electronically switchable time constants. Furthermore it includes electronically switchable inputs for tape drivers with reverse heads.

This device also detects pauses of music in Automatic Music Search (AMS) mode, with a delay time fixed externally by a resistor. The short-circuit proof output stage of the TEA0678 is differential and provides muting.

The device will operate with power supplies in the range of 7.6 to 12 V, output overload level increasing with increase in supply voltage. Current drain varies with supply voltage, noise reduction on/off and AMS on/off so it is advisable to use a regulated power supply or a supply with a long time constant.

Current drain varies with these variables: Supply voltage Noise reduction on/off AMS on/off.

Because of this TEA0678 current drain variation it is advisable to use a regulated power supply or a supply with a long time constant.