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One example is the Philips NORBIT family of logic building blocks. The PMOS and I 2 L logic families were used for relatively short periods, mostly in special purpose custom large-scale integration circuits devices and are generally considered obsolete. For example, early digital clocks or electronic calculators may have used one or more PMOS ...
The major drawback with NMOS (and most other logic families) is that a direct current must flow through a logic gate even when the output is in a steady state (low in the case of NMOS). This means static power dissipation, i.e. power drain even when the circuit is not switching, leading to high power consumption.
As the electron mobility in the n-type channel of NMOS MOSFETs is about three times that of the hole mobility in the p-type channel of PMOS MOSFETS, NMOS logic allows for an increased switching speed. For this reason NMOS logic quickly began to replace PMOS logic. By the late 1970s, NMOS microprocessors had overtaken PMOS processors. [16]
MOSFET (PMOS and NMOS) demonstrations Date Channel length Oxide thickness [1] MOSFET logic Researcher(s) Organization Ref; June 1960: 20,000 nm: 100 nm: PMOS: Mohamed M. Atalla, Dawon Kahng: Bell Telephone Laboratories [2] [3] NMOS: 10,000 nm: 100 nm: PMOS Mohamed M. Atalla, Dawon Kahng: Bell Telephone Laboratories [4] NMOS May 1965: 8,000 nm ...
Alternatively, rather than static logic gates, dynamic logic such as four-phase logic was sometimes used in processes that did not have depletion-mode transistors available. For example, the 1971 Intel 4004 used enhancement-load silicon-gate PMOS logic , and the 1976 Zilog Z80 used depletion-load silicon-gate NMOS.
A depletion-load NMOS NAND gate. In integrated circuits, depletion-load NMOS is a form of digital logic family that uses only a single power supply voltage, unlike earlier NMOS (n-type metal-oxide semiconductor) logic families that needed more than one different power supply voltage.
Logic families represent kinds of digital circuits, or methodologies for implementing logic expressions using transistors. Pages in category "Logic families" The following 39 pages are in this category, out of 39 total.
It is common to use this logic family for multiplexers and latches. [citation needed] CPL uses series transistors to select between possible inverted output values of the logic, the output of which drives an inverter The CMOS transmission gates consist of nMOS and pMOS transistor connected in parallel.