Question

The reverse saturation current of a diode at 25°C is 1.5 x 10^-9A. What will be the reverse current at temperature 30°C?

(a) 3 x 10^-9A

(b) 2 x 10^-9A

(c) 2.12 x 10^-9A

(d) 1.5 x 10^-9A

This question was addressed to me in an interview for internship.

Enquiry is from Characteristic Equation of Diode-2 topic in division Diode Circuit of Analog Circuits

Answer 1

Right choice is (c) 2.12 x 10^-9A

To explain I would say: The equation relating final reverse saturation current (Io2) to initial reverse saturation current (Io1) is given by

Io2 = 2^(∆T/10)Io1 Where ∆T is temperature change

Here ∆T = 5, Therefore, Io2 = 25/10 Io1 = 1.414 x 1.5 x 10^-9A = 2.121 x 10^-9A.