New BiCMOS delay model to include RC-limited BJT saturation effect

This paper presents an analytical model for the delay in a BiCMOS driver. The model covers all three modes of operation of the bipolar transistor (BJT) in a BiCMOS driver—low-level injection, high-level injection and RC−limited saturation. The associated transient collector current IC(t) of BJT, and the analytical derivation of corresponding propagation delay time τd of the BiCMOS driver is based on two important BJT parameters—the Knee current …