Clock wave noise reducer
AssigneeHewlett-Packard Company
InventorJohnny Q Zhang
Life of this patent
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Abstract
A clock circuit on an integrated circuit chip includes a driver having an output for deriving an output clock wave responsive to a clock wave of a clock wave source, a clock line having a first end coupled to the output of the driver, and a receiver having an input coupled to a second end of the clock line. The receiver has a resistive input impedance causing the clock line carrying the output clock wave to the input of the receiver to present to the driver output an impedance having a resistance-capacitance time constant that is a relatively small fraction of a period of the clock wave.
Claims7
Clock circuitry on an integrated circuit (IC) chip, the clock circuitry adapted to be responsive to a clock wave of a clock wave source, the clock circuitry comprising:
- a driver having first and second outputs for respectively deriving first and second complementary clock waves in response to the clock wave;
- a receiver having first and second inputs;
- first and second clock lines respectively connected between said first and second outputs of said driver and said first and second inputs of said receiver, the driver, receiver and clock lines being arranged so the clock waves arrive with relatively low amplitude variations at the receiver inputs, said receiver being constructed and arranged for amplifying the clock waves having the relatively low amplitude variations at said first and second inputs to voltages substantially equal to the high and low power supply voltages of the IC chip at a first output thereof, said first output deriving an amplified clock wave having clock wave transitions substantially coincident with clock wave transitions of the clock wave of the clock save source.
A circuit for removing common mode components from first and second complementary bi-level waveforms comprising first and second input terminals connected for respectively responding to the first and second waveforms, first and second DC power supply terminals, a differential amplifier connected to the first and second input terminals and to the first and second DC power supply terminals, the differential amplifier being arranged so that during first half cycles of the waveforms the common mode components are subtracted therein and during second half cycles of the waveforms an output terminal of the amplifier is supplied with one of the DC power supply voltages.
A circuit for removing common mode components from first and second complementary bi-level waveforms comprising first and second input terminals connected for respectively responding to the first and second waveforms, first and second DC power supply terminals, first and second differential amplifiers, each of the amplifiers being connected to the first and second input terminals and to the first and second DC power supply terminals, the first and second amplifiers respectively including first and second output terminals, the first differential amplifier being arranged so that during first half cycles of the waveforms the common mode components are subtracted therein and during second half cycles of the waveforms the first output terminal is supplied with the first DC power supply voltage, the second differential amplifier being arranged so that during the second half cycles of the waveforms the common mode components are subtracted therein and during the first half cycles of the waveforms the second output terminal of the amplifier is supplied with one of the second DC power supply voltages.
Dependencies are inferred from the claim text.