Line driver structures that enhance driver performance
AssigneeAnalog Devices, Inc.
InventorEdward Perry Jordan
Life of this patent
Estimating the term…
Abstract
Line drivers are provided that are suitable for driving communication cables (e.g., in Data Over Cable Service Interface Specification (DOCSIS) certified systems) without the need for output drivers and their size, power-consumption, noise and signal-distortion penalities. These line drivers directly couple switched current mirrors to a transformer's input winding to simultaneously provide currents in response to a differential input signal and a digital command signal and drive the load impedance to thereby realize a corresponding signal gain.
Claims22
A line driver that responds to a differential driver input signal and drives a load impedance with a signal gain that corresponds to a digital command signal, comprising:
- a transformer that has an input winding and also has an output winding for coupling across said load impedance;
- and
- at least one multiplying digital-to-analog converter (MDAC) that includes:
- a) a reference current source that generates a reference current in response to a respective side of said differential driver input signal;
- and
- b) a plurality of switched current mirrors that are directly connected to a respective side of said input winding and are referenced to said reference current source to thereby mirror said reference current into output currents that are switched to said respective side in response to said digital command signal.
A line driver that responds to a differential driver input signal and drives a load impedance with a signal gain that corresponds to a digital command signal, comprising:
- a transformer that has an input winding and also has an output winding for coupling across said load impedance;
- at least one reference current source that generates a reference current in response to a respective side of said differential driver input signal;
- and
- at least one set of switched current mirrors that are directly connected to a respective side of said input winding and are referenced to said reference current source to thereby mirror said reference current into output currents that are switched to said respective side in response to said digital command signal.
A line driver that responds to a differential driver input signal and drives a load impedance with a signal gain that corresponds to a digital command signal, comprising:
- a transformer that has an input winding and also has an output winding for coupling across said load impedance;
- a pair of initial multiplying digital-to-analog converters (MDACs) that each includes:
- a) an initial reference current source that generates an initial reference current in response to a respective side of said differential driver input signal;
- and
- b) a plurality of initial switched current mirrors that are referenced to said initial reference current source to thereby mirror said initial reference current into initial output currents that are switched in response to an initial portion of said digital command signal;
- and
- a pair of final multiplying digital-to-analog converters (MDACs) that each includes:
- a) a final reference current source that generates a final reference current in response to the initial output currents of a respective one of said initial MDACs;
- and
- b) a plurality of final switched current mirrors that are directly connected to a respective side of said input winding and are referenced to said final reference current source to thereby mirror said final reference current into final output currents that are switched in response to a final portion of said digital command signal.
Dependencies are inferred from the claim text.