Switch-Off Transient Analysis For Heterojunction Bipolar-Transistors In Saturation

Transient analysis of the heterojunction bipolar transistors switched from saturation to cutoff has been developed. The minority charges stored in the base and collector as a function of time are derived. The storage time of the heterojunction bipolar transistor is determined from the minority charge stored in the collector. The storage time can be significantly reduced using double heterojunction bipolar transistors. The present analysis is useful for determining non-quasi-static collector current during switch-off transient