Chapter 2

Q. 2.3

Find the percentage increase in the reverse saturation current of a diode if the temperature is increased from 25°C to 50°C.


Verified Solution

By (2.2),
\frac{(I_o)_2}{(I_o)_1} = 2^{(T_2 – T_1)/10}         (2.2)
\frac{(I_o)_2}{(I_o)_1} = 2^{(50 – 50)/10} × 100 \% = 565.7 \%

Static terminal characteristics are generally adequate for describing diode operation at low frequency.    However, if high-frequency analysis (above 100kHz) or switching analysis is to be performed, it may be necessary to account for the small depletion capacitance (typically several picofarads) associated with a reverse-biased p-n junction; for a forward-biased p-n junction, a somewhat larger diffusion capacitance (typically several hundred picofarads) that is directly proportional to the forward current should be included in the model.    (See Problem 2.25.)