DIGITAL DIFFERENTIAL SIGNAL TRANSMITTER FOR LOW SUPPLY VOLTAGE
First Claim
1. A digital differential signal transmitter circuit for a low supply voltage, comprising:
- signal selection switches composed of multiplexers which are respectively installed on two signal paths to select and output to the respective signal paths any ones of input differential signals and clock signals;
a differential phase correction circuit arranged between the two signal paths to be inputted with signals outputted from the two signal paths, delay output timing and correct a phase difference between two signals;
duty cycle correction circuits configured to detect edges of signals transmitted from the respective signal paths after phase correction is implemented, generate pulses, and control a switch for increasing and decreasing an output signal by the pulses so that duty cycles of signals outputted from the respective signal paths are corrected to be constant; and
a final output section configured to match an impedance of an output driver using a reference resistor having the same impedance as transmission lines for transmitting the input differential signals to a receiver, and output the input differential signals corrected in duty cycles to the transmission lines.
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Accused Products
Abstract
A digital differential signal transmitter circuit for a low supply voltage. A phase correction circuit for correcting digital signals transmitted through two signal paths in such a way as to have a phase relationship of differential signals and duty cycle correction circuits for correcting the digital signals in such a way as to maintain signal integrity in spite of changes in process, supply voltage and temperature are installed on the two signal paths so that the distortion of digital differential signals is compensated for. Power consumption at a final output section of the transmitter circuit is reduced. Impedances of the transmitter circuit and transmission lines are matched so that the transmitter circuit can operate insensitively with respect to operation circumstances.
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Citations
20 Claims
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1. A digital differential signal transmitter circuit for a low supply voltage, comprising:
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signal selection switches composed of multiplexers which are respectively installed on two signal paths to select and output to the respective signal paths any ones of input differential signals and clock signals; a differential phase correction circuit arranged between the two signal paths to be inputted with signals outputted from the two signal paths, delay output timing and correct a phase difference between two signals; duty cycle correction circuits configured to detect edges of signals transmitted from the respective signal paths after phase correction is implemented, generate pulses, and control a switch for increasing and decreasing an output signal by the pulses so that duty cycles of signals outputted from the respective signal paths are corrected to be constant; and a final output section configured to match an impedance of an output driver using a reference resistor having the same impedance as transmission lines for transmitting the input differential signals to a receiver, and output the input differential signals corrected in duty cycles to the transmission lines. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification