What is punch through in MOSFET?

What is punch through in MOSFET?

Punch through is addressed to MOSFETs’ channel length modulation and occurs when the depletion regions of the drain-body and source-body junctions meet and form a single depletion region.


IDM represents maximum limit current in MOSFET SOA (Safe Operating Area ).

What is punch through in VLSI?

When the drain is at a high enough voltage with respect to thesouce, the depletion region around thedrain may extend to the source, thus causing current to flow irrespective of the gate voltage( i.e., even if itis zero). This is known as apunchthroughcondition.

What is meant by punch through effect?

[′pənch‚thrü] (electronics) An emitter-to-collector breakdown which can occur in a junction transistor with very narrow base region at sufficiently high collector voltage when the space-charge layer extends completely across the base region.

Why pinch off occurs in MOSFET?

This phenomenon is known as “pinch-off” and the point where the inversion layer thickness is reduced to zero is called the “pinch-off point.” Pinch-off occurs because, at VSAT, the effective potential between the gate and substrate at the source end of the channel (Veff = VGS) is greater than the potential between the …

What is pinch off and punch through?

In MOSFET operation, punch through occurs when drain’s depletion region touches source’s depletion region. In saturation region, the only connection between drain and source is drain’s depletion region touching depletion region of source and channel. (Channel is pinched off near drain.)


VSD is a measure of the forward voltage drop of the integral body diode, by applying a set current to the source. The applied current is typically 1A and is specified in the datasheet along with the maximum limit of forward voltage drop.

How are MOSFETs rated?

For example, power MOSFETs are rated in terms of drain current, pin-to-pin voltage, power dissipation, channel temperature, and storage temperature. These characteristics are interrelated and cannot be considered separately. They also depend on external circuit conditions.

What is body effect in MOSFET?

Body effect refers to the change in the transistor threshold voltage (VT) resulting from a voltage difference between the transistor source and body.

How drain current changes with channel pinch off?

no channel exist at the drain end. but current flows due to the electric field in the depletion region. when electron comes to pinch off region, they all swept out to drain by the depletion region electric field. no of electrons reaching to drain is lesser but their average velocity increases.

What is inversion in a MOSFET?

The inversion layer provides a channel through which current can pass between source and drain terminals. Varying the voltage between the gate and body modulates the conductivity of this layer and thereby controls the current flow between drain and source. This is known as enhancement mode.

What happens during pinch off condition in MOSFET?

The channel of an enhancement-type MOSFET is said to be pinched off, when the effective gate-to- channel voltage at the drain end becomes less than the threshold voltage, and thus insufficient to maintain a layer of minority carriers across it (needed for the channel to exist).