Whats the difference between the min and max values of ID for this circuit.?

Question

a JFET has the following ratings: Vgs(off) = -2V to -5V and IDss=4mA to 12mA. The device is being used in a gate bias circuit with a gate supply voltage of Vgg = -1V. Whats the difference between the min and max values of ID for this circuit?

umm i got 6.68mA i kno its wrong

Answer 1

Do you mean IDSS? This is the drain to source current the device draws when the gate voltage is zero. The value of IDSS varies from unit to unit in a production lot, and the manufacturer has picked limits of 4 to 12mA for his limits for this product.

Do you mean what ID does the device draw when the Vg = -1 volt? Can't tell from these numbers. We know it is less than 12 mA, as changing Vg from 0 to -1 volt will reduce the current. We know it is not zero, as -1 volt is higher than Vgs(off).

But that is all we can say, it's between 0 and 12 mA.

Perhaps with the circuit, and the data sheet on the device I can narrow it down more.

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