Signal detection circuit not affected by minute voltage fluctuations contained in input signal and operation method therefor
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsHiromi Shimada, Harufusa Kondoh
Life of this patent
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Abstract
A reference voltage generating circuit (9) for supplying a reference voltage (Vag.+-..DELTA.V) is connected to a peak hold or tracking circuit (34). The setting value of the voltage (.DELTA.V) is determined to a value exceeding the minute voltage fluctuations, such as back pulses or noises, occasionally contained in the input signal (Vin), by the voltage division in the generating circuit (9). Therefore, in response to the input signal Vin in accordance with the alternate mark inversion, exact data which is not influenced by the minute voltage fluctuation can be detected by the data detector (33).
Claims9
A signal detection circuit for detecting pulse signals, having a variable magnitude, on an incoming signal line whereon voltage fluctuations, smaller than said pulse signals, tend to occur, said signal detection circuit comprising:
- comparator means having first and second input terminals for generating an output signal;
- means for applying data signals on said incoming signal line to said first input terminal of said comparator means;
- means for generating a first reference voltage having a magnitude proportional to each peak voltage of said incoming pulse signals;
- means for generating a second reference voltage having a magnitude slightly greater than the magnitude of said voltage fluctuations;
- means, responsive to said second reference voltage, for shifting the magnitude of said first reference voltage and generating a third reference voltage;
- and
- means for applying said third reference voltage to said second input terminal of said comparator means.
A method of operating a signal detection circuit for detecting pulse signals having variable amplitude on an incoming signal line, voltage fluctuation smaller than said pulse signals tend to occur on said incoming signal, said signal line detection circuit including comparator means having first and second input terminals for generating an output signal, said method comprising the steps of:
- applying data signals on said incoming signal line to said first input terminal of said comparator means;
- generating a first reference voltage having a magnitude proportional to each peak voltage of said incoming pulse signals;
- generating a second reference voltage having a magnitude slightly greater than the magnitude of said voltage fluctuation;
- obtaining a third reference voltage by shifting the magnitude of said first reference voltage in response to said second reference voltage;
- and
- applying said third reference voltage to the second input terminal of said comparator means.
Dependencies are inferred from the claim text.