Why does the drain current remain constant after the voltage across the drain and the source crosses the pinch off voltage in JFET?

Why does the drain current remain constant after the voltage across the drain and the source crosses the pinch off voltage in JFET?

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. this results a constant current at saturation.

What is the value of drain current when VGS pinch off voltage?

0A
(ii) For gate-to-source voltages VGS less than (more negative than) the pinch-off level, the drain current is 0A (ID=0A). (iii) For all levels of VGS between 0V and the pinch-off level, the current ID will range between IDSS and 0A, respectively.

What is the value of drain current when V pinch off voltage?

The pinch off voltage Vp is the value of Vds at which the drain current becomes constant and equal to Idss and is always measured at Vgs = 0 V.

Why does the current increase with the gate voltage?

So shouldn’t the charge concentration increase linearly with the gate voltage from the very beginning. If that is so the current should increase linearly as gate potential is increased from zero. Instead why does the current increase abruptly from zero when a threshold voltage is hit. Why is the sudden increase in carrier concentration?

When is 3V on gate the drain current is zero?

When 3V is on the gate (relative to source) and at Vds of zero volts the drain current is also zero but, if you increase the drain voltage the current rises from zero to a value dependent on the graph. Note that each MOSFET will have their own particular graph in their data sheet.

What is the pinch off voltage of a gate?

With the gate connected to the source, Vgs = 0, the pinch-off voltage is defined as the drain voltage, Vds, at which the channel changes from being resistive to being current limiting. The drain current, Id, is then at a maximum and is limited by the maximum channel width.

When does the drain current decrease in a JFET?

As the gate voltage, Vgs, becomes more negative, the gate progressively increases in thickness. That progressively restricts the channel width, until the channel width approaches zero, when the drain current, Id, is reduced to the minimum.