New applications of linear integrated circuits in the entertainment industry

Abstract

Advances in integrated circuit technology have for a long time been concerned with increasing function packing densities in digital systems. In linear circuits, however, it is not sufficient to consider only problems of complexity, since frequently there is also a requirement to handle significant power levels. Manufacturing technologies are now being perfected which will allow the combination of high power and complexity on a single linear integrated circuit. As a result new trends in the development of equipment employing linear circuitry are becoming clear. A prime example is the entertainment industry in which portable, domestic and in-car systems can all benefit from an increase in integration. For most portable equipment the use of complex ICs permits the inclusion of more sophisticated functions than previously without incurring any weight or bulk penalties. The TV receiver, by far the most complex electronic apparatus in the consumer field, will soon be realised using only 7 signal processing ICs. This will leave only a very few functions which require discrete components. In simpler appliances the reduction in the number of components will be even more dramatic. Portable tape recorders will soon be available which use only 3 integrated circuits, viz. preamplifier, power amplifier and function module. In a similar way the popular portable radio with less than 1 W of audio output power can be realised with only one chip. Higher quality home receivers will use a tuner followed by only 2 chips--a combined AM/FM demodulator and a power amplifier. Even the hi-fi field of stereo FM reception can be significantly rationalized. Future receivers will employ a tuner section and only 5 chips. The likely partitioning will be--separate AM and FM demodulators, stereo decoder and twin power amplifiers. In this paper 4 integrated circuits are described which will make a major contribution to this trend in integration. Two of these form part of a complete philosophy for the integration of both monochrome and colour TV receivers. The third combines all the preamplifier 401 functions of a tape recorder including AGC facility. Finally there is a 15 W audio amplifier which signifies another landmark in the power handling ability of single integrated circuits.