An n p n transistor has a base transport factor of 0998 an e

An n⁺⁺- p⁺- n transistor has a base transport factor of 0.998, an emitter efficiency of 0.997 and an Icp of 10 nA.

a.Calculate _o and _o.

b.If the base current is zero (i.e. the base terminal is open-circuited), what is the emitter current (hint: Collector-base leakage current is Icp in n-p-n transistors)?

Solution

a) _T = 0.998, Gamma = 0.997

o = Gamma*_{T = 0.998*0.997 = 0.995}

o = o/1-o

= 0.995/1-0.995

= 199

b). We know that the collector current

I_{C =} o I_B + Icp

where Icp = collector base leakage current in n-p-n transistor

Ic = Icp; base current is zero

IC = 10nA

Ic = o I_E

I_E = 10nA / 0.995 = 10.05 nA