As system bandwidths have increased, an accurate estimateof the noise contribution for each element in the signalchannel has become increasingly important. Many designersare not, however, particularly comfortable with thecalculations required to predict the total noise for an opamp, or in the conversions between the different des criptionsof noise. Considerable inconsistency between manufacturersin describing noise and, in some cases, incompletespecifications, have contributed to this confusion.