Patent ID: 8552766

Claim:
Threshold comparator with hysteresis comprising: an input terminal; a comparator circuit, having a first input, coupled to the input terminal for receiving an input voltage, a second input and an output for providing an output voltage having a first value, when the first input is at a higher voltage than the second input, and a second value, when the first input is at a lower voltage than the second input; a current generator, coupled to the input terminal and controlled by the output voltage for supplying a hysteresis current to the input terminal in the presence of selectively one of the first value and the second value of the output voltage; at least a first reference voltage source and a second reference voltage source, for providing, respectively, a first reference voltage and a second reference voltage, lower than the first reference voltage; a selective coupling circuit, controlled by the output voltage of the comparator circuit and configured to couple the second input of the comparator circuit to the first reference voltage source, in response to first edges of the output voltage, and to the second reference voltage source, in response to second edges of the output voltage, opposite to the first edges; and a third reference voltage source, for providing a third reference voltage, intermediate between the first reference voltage and the second reference voltage, wherein the selective coupling circuit is configured to couple the second input of the comparator circuit to the third reference voltage source after a controlled duration since each first edge and since each second edge of the output voltage.