Comparison of logic families and TTL data

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Comparison of logic families

Since RTL was introduced in the early 1960s. there has been a steady progression in technology; the design engineer now has a wide choice of integrated circuit ranges and operating parameters.

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It is apparent that speed/power comparisons are not sufficient in themselves. Other important parameters to be considered are noise immunity, supply voltage requirements and fan out.

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Power supply requirements Each logic type has different power supply requirements and since system economics can be greatly affected by the cost of power supplies it is important to establish exact power supply parameters.

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With the exception of the 74C series of devices, all series in the 74 family are of transistor-transistor-logic (TTL) construction. The 74C series (which is of CMOS construction) is pin compatible with all 74 family members and therefore the generic TTL title usually includes it.
TTL 74 family and CMOS 4000 family devices have generally superseded all other logic types.

TTL data

All devices are listed by generic family number, e.g. 7400. Certain devices may only be available, however, as members of as few as one series of the 74 family. Readers are referred to relevant data books for further details.

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Selection by function

Gates

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