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Custom design perspectives
Microelectronics and Reliability, Vol. 14, p. 383. Pergamon Press, 1975. Printed in Great Britain
CUSTOM DESIGN PERSPECTIVES E.
PICKVANCE,
Product Marketing Dept., ITT Semiconductors, Maidstone Road, Foots Cray, Kent ABSTRACT
The development of a custom integrated circuit involves a major commitment of resources by both manufacturer and customer, with no certainty of a satisfactory outcome. To maximise the chance of success, the customer looks f o r - - a successful track record in custom circuits, extensive capability in various technologies, mature and stable processes, modern equipment, all stages of manufacture on one site, good communications, prompt delivery of samples. The manufacturer looks f o r - - a clear specification of the circuit function, packaging and operating conditions (e.g. input and output interfaces and system speeds), sufficient order volume (in terms of both annual order rate and total production run), any special requirements on environmental testing, and realistic target price and delivery requirements. As the manufacturer's response to a particular enquiry for a custom circuit will depend on all the above factors, it is virtually impossible to set down precise criteria for a viable custom circuit. Probably more enquires are turned away on the grounds of inadequate quantities than for any other reason. Custom circuits in production volume at ITT
383
Semiconductors generally fall clearly into one of three categories: complex processing (e.g. washing machine program controller, touch tuning/control for TV sets), memory (e.g. RAMs, ROMs, shift registers, bucket brigade delay lines) and pure interfaces (e.g. drivers to match LED displays to MOS calculators, data highway drivers). The first two categories tend to use MOS technology because of the high packing density of circuit functions available from MOS. Bipolar technology tends to be the choice for interface circuits because higher currents can be handled in a given area, compared with MOS. The two technologies therefore complement one another, and both may be involved in an optimum solution to a customer's problem. New technologies such as NMOS can now be used, but clever design techniques are much more valuable to the customer than exotic IC technologies. While the customer's principal motive in considering custom design is usually the reduction of component costs, there are also cases where a customer wants special features not available on standard ICs that are otherwise suitable. The reduced component count resulting from the use of custom ICs also brings about important improvements in assembly costs, packing density and reliability.
CUSTOM DESIGN PERSPECTIVES E.
PICKVANCE,
Product Marketing Dept., ITT Semiconductors, Maidstone Road, Foots Cray, Kent ABSTRACT
The development of a custom integrated circuit involves a major commitment of resources by both manufacturer and customer, with no certainty of a satisfactory outcome. To maximise the chance of success, the customer looks f o r - - a successful track record in custom circuits, extensive capability in various technologies, mature and stable processes, modern equipment, all stages of manufacture on one site, good communications, prompt delivery of samples. The manufacturer looks f o r - - a clear specification of the circuit function, packaging and operating conditions (e.g. input and output interfaces and system speeds), sufficient order volume (in terms of both annual order rate and total production run), any special requirements on environmental testing, and realistic target price and delivery requirements. As the manufacturer's response to a particular enquiry for a custom circuit will depend on all the above factors, it is virtually impossible to set down precise criteria for a viable custom circuit. Probably more enquires are turned away on the grounds of inadequate quantities than for any other reason. Custom circuits in production volume at ITT
383
Semiconductors generally fall clearly into one of three categories: complex processing (e.g. washing machine program controller, touch tuning/control for TV sets), memory (e.g. RAMs, ROMs, shift registers, bucket brigade delay lines) and pure interfaces (e.g. drivers to match LED displays to MOS calculators, data highway drivers). The first two categories tend to use MOS technology because of the high packing density of circuit functions available from MOS. Bipolar technology tends to be the choice for interface circuits because higher currents can be handled in a given area, compared with MOS. The two technologies therefore complement one another, and both may be involved in an optimum solution to a customer's problem. New technologies such as NMOS can now be used, but clever design techniques are much more valuable to the customer than exotic IC technologies. While the customer's principal motive in considering custom design is usually the reduction of component costs, there are also cases where a customer wants special features not available on standard ICs that are otherwise suitable. The reduced component count resulting from the use of custom ICs also brings about important improvements in assembly costs, packing density and reliability.