Current Components inside Bipolar Junction Transistor (BJT) NPN BJT

BJT I-V characteristics Last class we derived the current equations in forward active for npn transistor current gain minority carrier lifetime in the base recombination of holes and collectors in base injection of holes from base into emitter

BJT Early effect Early effect results from base width modulation –Collector-base junction is reverse-biased –Gives rise to a small modification in the collector current expression –Most of depletion region is on collector side of the collector-base junction –Depletion width on base side varies a bit with V CB –Effective base width decreases, collector current increases –Gives a finite output resistance r o