Effect of BJT’s parasitics on computing cells for analog decoders
Nicolas Duchaux, Cyril Lahuec, Fabrice Seguin, Matthieu Arzel, Michel Jézéquel · 2008
This paper analyzes the effect of inherent bipolar transistor parasitic elements on the computing nodes performance used in BJT analog decoders. It is shown that these undesirable effects significantly degrade, up to 85%, the conversion of Log-Likelihood Ratios into probabilities. This can lead to a wrong decoding outcome when complex computing nodes are designed. Simulation results are shown for a 0.25-mum BiCMOS process from NXP.