Adc Telecommunications, Inc.

John E Donohue

Clarke V Greene

Aravanan Gurusami

An optical distribution node is provided. The optical distribution node includes a laser transceiver that is coupleable to at least one fiber optic link. The optical distribution node communicates upstream and downstream digital data with the head end over the at least one fiber optic link. The optical distribution node further includes a data concentrator coupled to the laser transceiver. Further, for each of at least one coaxial cable link, the optical distribution node includes a frequency translator and a node modem. The frequency translator receives and translates the upstream digital data from modems on the at least one coaxial cable link to a different carrier to provide a signal to the modems on the at least one coaxial cable link for collision detection. The node modem is coupled between the coaxial cable link and the data concentrator. The node modem demodulates upstream digital data for the data concentrator and modulates downstream digital data for transmission over the coaxial cable link.

Digital node for hybrid fiber/coax network

Improved phase locked loops are described which handle momentary breaks in an input communication channel. The phase locked loops provide the capability to 'hold' the output clock in a communication system at or very near the last output frequency before the loss of input data. Such phase locked loops include a differential phase detector, an electronic selector circuit, and an operational amplifier based loop filter circuit. The electronic selector circuit provides the differential output of the phase detector at a pair of inputs to the operational amplifier. A voltage controlled oscillator is coupled to an output of the operational amplifier and provides an output frequency for the phased locked loop circuit. The electronic selector circuit is operable to control the input to the operational amplifier to hold an output frequency of the voltage controlled oscillator at a substantially constant frequency.

Systems and methods for holdover circuits in phase locked loops

An optical distribution node for an hybrid fiber/coax network is provided. The optical distribution node includes a laser transmitter coupleable to a fiber optic link that transmits upstream, digital data to a head end of the network. The node also includes a data concentrator coupled to provide the upstream, digital data to the laser. For at least one coaxial cable link of the network coupleable to the optical distribution node, the node also includes a frequency translator that receives the upstream, digital data modulated on a first carrier frequency and retransmits the upstream, digital data to the plurality of modems for collision detection. The node also includes a data interface coupled between the at least one coaxial cable link and the data concentrator that determines whether the upstream data is valid.

Digital return path for hybrid fiber/coax network

A voltage regulator is provided. The voltage regulator comprises a first voltage-controlled current regulator having a first power input and at least one additional voltage-controlled current regulator having at least one other power input. The first and the at least one additional voltage-controlled current regulators have first and second current paths, respectively, and a common output node. The voltage regulator also includes an error amplifier that is responsive to the common output node. The error amplifier further has an output. The output of the error amplifier provides a common feedback signal to the first and the at least one additional voltage-controlled current regulators so as to establish selected currents drawn by the first and the at least one other power inputs and provided to the common output node.

Current balancing for voltage regulator having inputs from multiple power supplies

A phase-locked loop utilizes a pair of diodes in a loop filter design for providing fast acquisition of a reference signal during an acquisition mode, while maintaining a more narrow bandwidth in a locked mode of operation. During the acquisition mode, the diodes are conducting and the loop filter bandwidth is wide, which provides for a faster response time. As the reference signal is acquired, the diodes no longer conduct and the loop filter bandwidth becomes more narrow for tracking the reference signal.

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Ridgefield, CT, United States of America

John E Donohue