Question

A silicon diode is connected to a load resistance `R_(L)` as shown in the figure. If `V_(in)=15V` and `R_(L)=10kOmega`
(a) If barrier voltage, `V_(B)=0.7V` then calculate
(i) output voltage across `R_(L)`
(ii) current in diode and ltbRgt (iii) forward resistance.
(b) If diode is assumed ideal, then what will be
(i) output voltage and
(ii) output current in diode?

Answer 1

(a) (i) `V_(out)=V_( i n)-V_(B)=15-0.7=14.3V`
(ii) `L=(V_(out))/(R_(L))=(14.3)/(10xx10^(3))=1.43mA`
(iii) `r_(f)=(V_(B))/(I)=(0.7)/(1.43xx10^(-3))=490Omega`
(b) For ideal diode, `r_(f)=0,V_(B)=0`
(i) `V_(out)=V_(i n)=15V`
(ii) ` I=(V_(out))/(RF_(L))=(15)/(10xx10^(3))=1.5mA`