Variable latching phenomenon in CE BJT and its impact

Sustained scaling for TerraHertz SiGe HBT has led to transit frequency = 315GHz at 300K but it has simultaneously degraded BV_ceo to 1.63V. This has placed a high premium on UHF analog circuit design A theoretical formalism of the variable latching phenomena of CE BJT under various drive conditions, discovered by the Author in 1989, is one of the central problems in the design of high speed circuits. None of the industrial standards namely VBIC, HICUM and MEXTERM have been able to capture this feature. This paper takes a circuit plus device approach to develop a single analytic relation to model the variable latching phenomena of CE BJT current sources. This analytic relationship has been verified by experimental results using 2N3055 CE current sources with 90 percent confidence level. Proposed analytic relationship embedded in the compact model of HSPICE will enable exceptional model-to-hardware correlation in simulations of the variable latching phenomena and thereby lead to considerable improvement in concept-to-design-to-industrial production. This in turn will vastly change the scale of economy of IC chips production. This study has also established tentatively that Universal Hybrid-pi model is the correct small signal model of CE BJT which has been reported in JSSC-July-16-0310.