Current Sources and Voltage References

Characteristics of the JFET

Using JFETs and CRDs to Create Current Sources

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normal operation, though, the V

GD

is much higher than the V

GS

. However, JFETs are

manufactured according to a particular process, much of which dictates the break-

down voltage of the device. As a result, JFETs normally use the

same value for both

V

(BR)GSS

and V

(BR)GDS

, although the latter is not usually specified other than in the

absolute maximum ratings for V

GD

. Actually, this gate-to-drain voltage is responsible

for most of a JFET’s tiny leakage current (I

GD

), which like any P-N junction increases

with either increased voltage or temperature.

Although the ...