US 6,643,324 B1 · Pad cell circuit-integrated, differential-signal equalization receiver for integrated circuit and method of boosting and equalizing high frequency differential signals

Abstract

An equalization receiver responds to two differentially-related digital input signals occurring at a predetermined communication frequency. First and second input devices respond to the input signals and supply drive signals of a magnitude amplified relative to input signal by a factor related to the current conducted by the input devices. First and second current separate sources are connected to conduct current through the first and second input devices. An equalization circuit is connected between the first and second current sources. The equalization circuit has a frequency dependent impedance characteristic which exhibits a minimum impedance and a maximum coupling of the first and second current sources for the greatest current conductivity and the greatest amplification at the predetermined frequency. The greater amplification creates a more amplified output signal which compensates for the high frequency filtering and attenuation characteristics of the cable at higher frequencies but allows the digital signals to remain relatively unaffected at lower frequencies where the cable exhibits relatively insignificant filtering and attenuation characteristics. The method of the present invention achieves related and similar functionality.

Claims24

Dependent claims

An equalization receiver responsive to two differentially-related digital input signals occurring at a communication rate of a predetermined frequency, comprising:

a first input device responsive to a first digital input signal and to supply a first drive signal of a magnitude amplified relative to the first digital input signal by a factor related to current conducted by the first input device;
a first current source connected to conduct current through the first input device;
a second input device responsive to a second digital input signal to supply a second drive signal of a magnitude amplified relative to the second digital input signal by a factor related to the current conducted by the second input device;
a second current source connected to conduct current through the second input device, the first and second current sources being separate from one another;
a differential amplifier responsive to first and second drive signals to supply an output signal related to the relative difference in magnitude of the first and second drive signals;
and
an equalization circuit connected between the first and second current sources, the equalization circuit having a frequency dependent impedance characteristic which exhibits a minimum impedance and a maximum coupling of the first and second current sources for the greatest current conductivity of and the greatest amplification of the relative magnitudes of the first and second drive signals by the first and second input devices at the predetermined frequency, the more amplified relative magnitudes of the first and second drive signals causing the differential amplifier to deliver a more amplified output signal.

4 more elements

A method of boosting and equalizing a response to two differentially-related digital input signals occurring at a communication rate of a predetermined frequency over pair of conductors defining a channel of a multichannel communication cable, comprising the steps of:

supplying a first drive signal derived from one input signal conducted by one conductor of the pair of conductors of the channel of the cable;
amplifying the first drive signal relative to the one input signal by a factor related to a current conducted from a first current source by a first amplifying device;
supplying a second drive signal derived from the other input signal conducted by the other conductor of the pair of conductors of the channel of the cable;
amplifying the second drive signal relative to the other input signal by a factor related to a current conducted from a second current source by a second amplifying device;
and
coupling the first and second current sources together to achieve a combined current conductivity and the greatest amplification of the relative magnitudes of the first and second drive signals at the predetermined frequency.

3 more elements

Dependencies are inferred from the claim text.

Pad cell circuit-integrated, differential-signal equalization receiver for integrated circuit and method of boosting and equalizing high frequency differential signals

Life of this patent

Pad cell circuit-integrated, differential-signal equalization receiver for integrated circuit and method of boosting and equalizing high frequency differential signals

Life of this patent

Abstract

Claims24