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Dr. D. J. Jackson Lecture 12-1Electrical & Computer Engineering
ECE380 Digital Logic
Implementation Technology:
Buffers, Tri-state gates,
Transmission gates
Dr. D. J. Jackson Lecture 12-2Electrical & Computer Engineering
Buffers
• In circuits where a logic gate has to drive a
large capacitive load, buffers are often used
to improved performance
• Buffers can be created with different amounts
of drive capability (depending on the size of
the transistors used to construct them)
– Larger transistors => more current handling
capability
– A common use of a buffer is to control a light-
emitting diode (LED)
• Buffers have greater fan-out than other
(regular) logic gates
