TDA7335

® TDA7335 STEREO PREAMP + AMS + DOLBY B* NOISE REDUCTION PROCESSOR DUAL CHANNEL PROCESSOR FOR PLAYBACK APPLICATIONS. STEREO DOLBY B NR SYSTEM LOW NOISE HEAD PREAMPLIFIER MUTE, AUTOREVERSE, AMS (AUDIO MUSIC SENSOR) FUNCTIONS INTERNAL SWITCHES FOR EQUALIZATION DOLBY REFERENCE LEVEL -6dBm (388.2mVRMS) MINIMUM NUMBER OF EXTERNAL COMPONENTS LOW SUPPLY CURRENT (18mA) MIXED BIPOLAR/CMOS TECHNOLOGY DESCRIPTION The TDA7335 is a monolithic BICmos IC designed for use in stereo cassette player systems. The device includes two separate audio channels composed by low noise preamplifier, Dolby B noise reduction system and Audio Music Sensor. The dual preamplifier contains mute, autoreverse, metal/normal facilities for amplification of low level signal in applications requiring very low noise performances. Each channel consists of two cascaded operational amplifiers. The first one, AMP1, has a fixed gain of 36dB, low noise forward/reverse switchable input, and allows magnetic heads connection directly to ground. The second one, AMP2, is a standard operational amplifier whose equalizing external components fix the frequency response. The Audio Music Sensor circuit detects the interprogram space and then the starting point of musical programs (the interprogram time and program detection time are externally selectable). The device contains Dolby B decoder NR chains requiring very few external components and do not require coils. * Dolby B and the Double-D symbol are trademarks of Dolby Labora...