1.

Consider a Darlington amplifier. In the self bias network, the biasing resistances are 220kΩ and 400 kΩ. What can be the correct value of input resistance if hfe = 50 and emitter resistance = 10kΩ.(a) 141 kΩ(b) 15 MΩ(c) 20 MΩ(d) 200 kΩI had been asked this question during an online exam.The query is from Cascade and Darlington Amplifier topic in chapter General and Feedback Amplifiers of Analog Circuits

Answer» CORRECT option is (a) 141

To elaborate: R’ = 220k||400k = 142

RI = (1+hfe)^2RE = 26MΩ

RI’ = 26M||142k = 141.22 K.


Discussion

No Comment Found

Related InterviewSolutions