EDN, October 2nd, 2003
SUPPOSE YOU CASCADE two lowpass filters having rise times [t.sub.a] and [t.sub.b]. You can estimate the rise time of the combination ([t.sub.a+b]) according to the root-sum-of-squares (RSS) formula: [t.sub.a+b] = [square root of ([([t.sub.a]).sup.2] + [([t.sub.b]).sup.2])]. The RSS formula derives from the central-limit theorem, which applies well to the sort of lowpass-filtering effects found in I/O drivers; chip packages; scope probes; BNCs; and other simple, one-pole linear filters.
Are there cases in which the RSS formula does not apply? Yes. One prominent exception case is the lossy tr...
HighBeam Research, Free Preview: 'Rise time of lossy transmission lines.(signal integrity)'... Full Membership required for unlimited access. Free 7-day trial.
Subscribers: HighBeam content is only available to HighBeam subscribers. Click the link above for more information.
