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depletion Vs enhancement

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brahma

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enhancement vs depletion

Why there must be depletion and enhancement MOSFETs, i can understand its mathematical difference, but i want to know what for we need two modes? where their application varies?
 

Deplation mode MOSFETs are controled both from bulk substrate and gate. I don't have the experience to suggest an example of real implementation, but I guess that this will probably work in low power low voltage application where you can control the channel with less voltage over the gate.

I suggest " Mixed Analog-Digital VLSI devices and technology", Y. Tsividis, World Scientific 2002. There are significantly less mathematics and more physical explanation of the MOST function.

But then again, we need a more experienced designer to answer this...

D.
 
Well, MOSFETs are of two kinds:

1. Depletion
2. Enhancement

In the Depletion type of MOSFETs, the channel between the Source and Drain already exsists. When a voltage is applied this channel gets depleted slowly. Hence the name Depletion MOSFET. So in essence, the conduction in this MOSFET will stop or come to a minimum after the entire channel has depleted.

In the Enhancement MOSFET, no channel exsists between the Source and Drain. When a voltage is applied, a channel is created between the source and drain thereby causing a current to flow between the terminals.

Enhancement MOSFETs are mostly used for normal ICs while depletion mode MOS are used for specific applications where we need this kind of behavior.
 
welll...depletion mosfet has its channel i.e it conducts even thogh u wont apply any voltage..also even if u apply some -ve voltage it ll work to some +ve voltages...
ok//n enhancement mosfets work only at +ve voltages..ok if u want to control curr at +,-ve volts u ll go for depletion mos......here i talked abt nmos.
 

plz u should read microelectronics circuit 4th edition or 5th edition u will be able to know best abt ur question
 

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