punchthru, resulting in destruction of the FET
An enhancement MOSFET doesn't conduct current across the drain to source unless a voltage is applied to the gate. When sufficient voltage is applied to the gate of the transistor, currents flows from drain to source. A MOSFET acts as a switch or amplifier in a circuit.
yes.
MOSFET stands for Metal Oxide Semiconductor Field Effect Transistor, It is broadly Classified into Depletion type MOSFETS and Enhancement type MOSFETS. Depletion type MOSFETS are further classified into P-Channel and N-Channel Depletion type MOSFET, Similarly Enhancement type MOSFETS are further classified into P-Channel and N-Channel Enhancement type MOSFET.
To make a depletion MOSFET, the channel must be doped with carriers; this is in total opposite to an enhancement MOSFET which avoids carriers in the channel at all cost. (because the carriers in the channel become the subthreshold leakage current) Since you need to pinch the channel against the substrate to guarantee to turn off the channel completely, there must be a reverse bias between the substrate and the source terminal. As a result, the source terminal of an N type depletion MOSFET must be tied to Vdd. This is also a complete opposite to enhancement MOSFET. In order to turn off the channel quickly, the carriers in the channel of depletion MOSFET are usually planted shallowly. This is a drastically different from enhancement MOSFET that carriers must be planted deeply into source terminal in order to support a large diffuse current. The construction of depletion MOSFET thus requires far less diffusion time than enhancement MOSFET.
channel
It depends on: 1. technology, whether it's a JFET, enhancement-mode IGFET/MOSFET or depletion-mode IGFET/MOSFET, and 2. polarity, whether it's an N type or P type. More info needed for this one.
An e-mosfet is and "enhancement" mosfet. A d-mosfet is a "depletion" mosfet. These essentially show what mode the mosfet operates in when a voltage is applied to the gate. . An enhancement mode mosfet is normally non-conducting but conducts when the channel is enhanced by applying a voltage to the gate and pulling carriers into the channel. A depletion mode mosfet normally conducts but becomes more and more non-conducting as carriers are depleted or pulled out of the channel by applying a voltage. The polarity of the voltage depends on whether it is an N channel or P channel. P channel uses positively doped silicon while N channel uses negatively doped silicon. N channel fets are used wherever possible because N material conducts better than P material. There are basically two types of fet, the jfet and the mosfet. The jfet uses a single junction to control the channel hence draws some current. Bipolar transistors use two junctions. In the mosfet (Metal Oxide Semiconducting Field Effect Transistor) there is no such junction hence draw so little current for control purposes it can be regarded as zero. The gate is isolated from the channel by a very thin layer of metal oxide (usually chromium dioxide). An enhacement mode mosfet can be turned on by applying a voltage then removing the wire to the gate. The channel will then remain conducting for some time.
An enhancement MOSFET doesn't conduct current across the drain to source unless a voltage is applied to the gate. When sufficient voltage is applied to the gate of the transistor, currents flows from drain to source. A MOSFET acts as a switch or amplifier in a circuit.
high...
yes.
This refers to the voltage Vds that counteracts the opening of the n-channel (NMOS), at the drain end. Since the width of the channel is a function of Vgs - Vtn, the mosfet saturates (pinches off) when Vds is greater or equal than/to Vgs - Vtn.
A depletion MOSFET is a MOSFET that is normally on. It outputs maximum current when the gate-source voltage is 0V. As the gate-source voltage increases, the drain-source channel becomes more resistive and the current decreases. An enhancement MOSFET has the opposite behavior. It is normally off. It outputs no current when the gate-source voltage is 0V. As the gate-source voltage increases, the drain-source channel becomes less resistive and the current increases.
The basic difference is between JFET and enhanced MOSFET,although the construction of JFET and depletion MOSFET is different but their most of the characteridtics are same,i.e shockly equation can be applied on both of them,but in JFET we cant give to gate voltage, the +ve value,because it does not works, but in depletion we can give,but some limited +ve value. Now enhanced MOSFET is different,shockly equation cant be applied.The transfer characteristics are purely in +ve Vg region. i.e for E-MOSFET Vg should be > 0,for its proper function.
It can be either a Bipolar Junction Transistor (NPN or PNP) or a Field Effect Transistor (N channel JFET, P channel JFET, N channel MOSFET, or P channel MOSFET).
MOSFET stands for Metal Oxide Semiconductor Field Effect Transistor, It is broadly Classified into Depletion type MOSFETS and Enhancement type MOSFETS. Depletion type MOSFETS are further classified into P-Channel and N-Channel Depletion type MOSFET, Similarly Enhancement type MOSFETS are further classified into P-Channel and N-Channel Enhancement type MOSFET.
Of course it is possible to make an inverter with a p-MOSFET!
To make a depletion MOSFET, the channel must be doped with carriers; this is in total opposite to an enhancement MOSFET which avoids carriers in the channel at all cost. (because the carriers in the channel become the subthreshold leakage current) Since you need to pinch the channel against the substrate to guarantee to turn off the channel completely, there must be a reverse bias between the substrate and the source terminal. As a result, the source terminal of an N type depletion MOSFET must be tied to Vdd. This is also a complete opposite to enhancement MOSFET. In order to turn off the channel quickly, the carriers in the channel of depletion MOSFET are usually planted shallowly. This is a drastically different from enhancement MOSFET that carriers must be planted deeply into source terminal in order to support a large diffuse current. The construction of depletion MOSFET thus requires far less diffusion time than enhancement MOSFET.