Table of Contents
Why is NAND faster than and?
In the industry NAND is preferred over NOR most of the time. NAND is a better gate for design than NOR because at the transistor level the mobility of electrons is normally three times that of holes compared to NOR and thus the NAND is a faster gate.
Which circuit uses fewer transistors?
Pass transistor logic often uses fewer transistors, runs faster, and requires less power than the same function implemented with the same transistors in fully complementary CMOS logic. XOR has the worst-case Karnaugh map—if implemented from simple gates, it requires more transistors than any other function.
Why is it better to build a decoder using NAND gates rather than AND gates?
But some binary decoders are constructed using NAND gates instead of AND gates for their decoded output, since NAND gates are cheaper to produce than AND’s as they require fewer transistors to implement within their design.
Why do we prefer NAND gates more than NOR?
In general, cells are designed to have similar drive strength of pull up and pull down structures to have comparable rise and fall time. NAND gate has better ratio of output high drive and output low drive as compared to NOR gate. Hence NAND gate is preferred over NOR.
Why are NAND and NOR gates more popular?
NAND and NOR gates are more popular as these are less expensive and easier to design. Also other functions NOT AND OR can easily be implemented using NAND/NOR gates. Thus NAND NOR gates are also referred to as Universal Gates.
What is the relationship between transistors and gates?
When the gate of a transistor is ON (or has a value 1) then electricity flows from the source to the sink and the transistor is said to be ON. Otherwise when the gate of a transistor is OFF (or has a value 0) then electricity does not flow from the source to the sink and the transistor is said to be OFF.
How transistors make logic gates?
The use of transistors for the construction of logic gates depends upon their utility as fast switches. When the base-emitter diode is turned on enough to be driven into saturation, the collector voltage with respect to the emitter may be near zero and can be used to construct gates for the TTL logic family.
How does a transistor NAND gate work?
In digital electronics, a NAND gate (NOT-AND) is a logic gate which produces an output which is false only if all its inputs are true; thus its output is complement to that of an AND gate. A LOW (0) output results only if all the inputs to the gate are HIGH (1); if any input is LOW (0), a HIGH (1) output results.
How many transistors are needed for a NOT gate?
A NOT gate/Intervter has 2 transistors(pmos and nmos). A two input AND gate has a minimum of 6 transistors.