Stephen R Nelson

US Patent:

7978800, Jul 12, 2011

Filed:

Oct 3, 2003

Appl. No.:

10/678685

Inventors:

Darin J. Douma - Monrovia CA, US
Rudolf J. Hofmeister - Sunnyvale CA, US
Stephen Nelson - Cupertino CA, US

Assignee:

Finisar Corporation - Sunnyvale CA

International Classification:

H03D 3/24
H04L 7/02
H03L 7/00

US Classification:

375354, 375373, 375359, 327141, 327 2, 327 3

Abstract:

A translation circuit for mediating between a fiber-optic controller chip and a host device. The translation circuit may be on a fiber-optic transponder. The controller chip includes a phase locked loop that outputs a short synchronization signal when a hunting frequency passes through a target data signal frequency while hunting for a data signal and outputs a synchronization signal when the phase locked loop is locked onto a data signal. The translation circuit distinguishes between the synchronization signals and generates a lock signal when the phase locked loop is locked onto a data signal, but does not when the hunting frequency passes through the target data signal frequency. The lock signal may be used by a host device into which the fiber-optic transponder has been in installed. Errors from misinterpreted signals can thus be mitigated.