Abstract: A fractional rate LC VCO and compensating divider circuit to avoid bit-rate interference includes an LC PLL having an input for receiving a reference clock signal, an N-stage ring VCO with rotating injection having an input coupled to an output of the LC PLL and an output for providing an output clock signal, a first divider circuit having an input coupled to an output of the N-stage ring VCO and an output coupled to the LC PLL, a second divider circuit having an input coupled to the output of the LC PLL, and an M-stage reference ring PLL having an input coupled to an output of the second divider and an output coupled to the N-stage ring VCO.

Abstract: A receive channel offset correction scheme utilizes “eye edge” samplers and demultiplexers already present and essential for operation of the CDR algorithm, and adds only simple word-rate logic, with no new analog circuitry. The result is the ability to precisely determine the offset polarity as well as to get an approximate immediate measure of the offset magnitude. The offset detected includes all of the analog circuitry in the channel, including the samplers themselves.

Abstract: A fractional rate LC VCO and compensating divider circuit to avoid bit-rate interference includes an LC PLL having an input for receiving a reference clock signal, an N-stage ring VCO with rotating injection having an input coupled to an output of the LC PLL and an output for providing an output clock signal, a first divider circuit having an input coupled to an output of the N-stage ring VCO and an output coupled to the LC PLL, a second divider circuit having an input coupled to the output of the LC PLL, and an M-stage reference ring PLL having an input coupled to an output of the second divider and an output coupled to the N-stage ring VCO.

Abstract: A clock circuit includes a frequency or phase comparator for receiving a reference clock signal, an LC VCO coupled to the comparator, a feedback divider coupled between the LC VCO and the comparator, a clock distribution chain coupled to the feedback divider and the first VCO, and a DLL or injection-locked ring-VCO coupled to the clock distribution chain for providing a plurality of phased output clock signals.