`
`Michael Nootbaar
`TDK Semiconductor Corp.
`
`March 2000 Plenary
`
`1
`
`CISCO 1038
`Cisco v. ChriMar
`
`
`
`Isolation Benefits
`
`• The Discovery Circuit must be isolated, regardless of the
`final determination on power isolation
`• Power over signal pairs allows use of existing transformers
`for isolation
`• Power over unused pairs requires additional discovery
`isolation or complete discovery circuit in the isolated (high
`voltage) domain
`
`March 2000 Plenary
`
`2
`
`CISCO 1038
`Cisco v. ChriMar
`
`
`
`Long Term Complexity/Cost
`
`• Power over signal pairs allows easier integration of
`discovery & power control circuitry onto the PHY
`• Decreases system cost by lowering parts count
`• Short term may require extra complexity until integrated
`solutions become available, but the integrated solutions
`will come quickly
`• Mid-Span insertion is more complex, but let’s not increase
`the long term complexity for a stop-gap measure!
`
`March 2000 Plenary
`
`3
`
`CISCO 1038
`Cisco v. ChriMar
`
`
`
`Compatibility
`
`• Compatible with existing installations
`• Looking forward: we need to address any signal quality
`concerns now anyway if we want to maintain the
`possibility of 1000BT future compatibility, even if we use
`the unused pairs.
`
`March 2000 Plenary
`
`4
`
`CISCO 1038
`Cisco v. ChriMar
`
`