Limitations of IC technology

Chapter Limitations of IC technology

Teach Yourself Electricity and Electronics Third Edition Book
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Teach Yourself Electricity and Electronics Third Edition Book

  • ReliabilityIntegrated circuits fail less often, per component-hour of use, than appliances thatmake use of discrete components. This is mainly a result of the fact that all intercon-nections are sealed within the IC case, preventing corrosion or the intrusion of dust.The reduced failure rate translates into less downtime, or time during which theequipment is out of service for repairs.Ease of maintenanceIntegrated-circuit technology lowers maintenance costs, mainly because repair proce-dures are simplified when failures do occur.Many appliances use sockets for ICs, and replacement is simply a matter of findingthe faulty IC, unplugging it, and plugging in a new one. Special desoldering equipmentis used with appliances having ICs soldered directly to the circuit boards.Modular constructionModern IC appliances use modular construction. In this scheme, individual ICs per-form defined functions within a circuit board; the circuit board or card, in turn, fits intoa socket and has a specific purpose. Computers, programmed with customized soft-ware, are used by repair technicians to locate the faulty card in an appliance. The wholecard can be pulled and replaced, getting the appliance back to the consumer in theshortest possible time. Then the computer can be used to troubleshoot the faulty card,getting the card ready for use in the next appliance that happens to come along with afailure in the same card.Modular construction can theoretically be used with discrete-component design.But this is rarely done. When a device is sophisticated enough to need modular con-struction, IC design is usually needed to keep the size within reason. Can you envisionseveral people, or perhaps a crane, pulling and replacing a 500-pound, 10-by-15-footcard from an appliance as big as a house?Limitations of IC technologyNo technological advancement ever comes without some sacrifice or compromise. In-tegrated circuits aren’t a ticket to electronic utopia.Inductors impracticalWhile some components are easy to fabricate onto chips, other components defy the ICmanufacturing process. Inductances, except for extremely low values, are one suchbugaboo. Devices using ICs must generally be designed to work without inductors. For-tunately, resistance-capacitance (RC) circuits are capable of doing most things that in-ductance-capacitance (LC) circuits can do.Mega-power impossibleThe small size and low current consumption of ICs comes with a “flip side.” This is the factthat high-power amplifiers cannot, in general, be fabricated onto semiconductor chips.Limitations of IC technology523