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TTL VS Cmos , advantages and disadvantages

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PrescottDan

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What are the advantages and disadvantages to use TTL over Cmos or vise versa

Using a Transistor was a switch has what advantages and disadvantages to use a CMOS FET?

A FET as a Switch can handle a Higher positive voltage and lower Negative voltage without getting damaged?

A Transistor as a switch can be damaged with more then 5 volts on the base input? and a negative voltage of -1 volt will damage the input base

A FET can have +15 positive and negative voltage on the Gate without getting damaged?

A FET is faster at switching compared to a Transistor?

A FET has more input and output capacitance then a transistor?

TTL gates can get damaged if to high or low voltage? a CMOS gate can handle higher and lower voltages without getting damaged

A CMOS gate has more capacitance then a TTL gate? the capacitance does what?

Why would a designer use CMOS over TTL logic chips?

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CMOS logic Ic chips have less "propagation delay" then TTL logic ic chips?
 

All your questions are answered in the respective data sheets for each device. You use a type suited to your application, there are high power and low power, fast and slow, low voltage and high voltage versions of all the devices you mention.

Brian.
 

There are over 100 logic families available from DigiKey. Tradeoffs exist for speed, output impedance,,fanout, cost,,voltage,,current transition frequency, input threshold and noise margin.

LVC2 are very popular for logic and used in ARM chips with 25 Ohm output resistance at low voltage and high speed with low quescent current,,and I/O ESD protection.
 

a CMOS FET?
There is no such thing. Cmos has two complementary Mosfets, not a single FET.

A Transistor as a switch can be damaged with more then 5 volts on the base input? and a negative voltage of -1 volt will damage the input base
Don't you know that there are NPN transistors and PNP transistors? Their voltage spec's are completely opposite so the voltages and polarities you are asking about do not make any sense. A datasheet tells you all about it.

Instead of asking millions of questions, why don't you study and learn about electronic parts? Maybe go back to school?
 

A reason some engineers use CMOS instead of TTL is because of the greater noise immunity. However they forget that due to CMOS.s much higher impedance's it is much easier to induce noise in to a CMOS circuit which negates the advantage CMOS has here. Another reason is because of the lower power consumption, however CMOS is a lot slower than TTL. So use CMOS when you want to save power and TTL when you want speed. This statements applies to the 74LS00 and 4000 series chips. Newer CMOS designs such as 74ACT or 74HCT have the advantages of both TTL and CMOS.
 

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