Threshold comparator with hysteresis and method for performing threshold comparison with hysteresis

Method for performing threshold comparison with hysteresis of a voltage comprising:

• supplying an input voltage to a first input of a comparator circuit, having a second input and an output configured to provide 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;
• supplying a hysteresis current to the first input in the presence of selectively one of the first value and the second value of the output voltage;
• providing the second input of the comparator circuit with a first reference voltage, in response to first edges of the output voltage, and a second reference voltage, lower than the first reference voltage, in response to second edges of the output voltage, opposite to the first edges;
• and
• providing the second input of the comparator circuit with a third reference voltage, intermediate between the first reference voltage and the second reference voltage, after a controlled duration since each first edge and since each second edge of the output voltage.

A threshold comparator with hysteresis comprising:

• a comparator circuit configured to provide an output voltage including a first output state when an input voltage on a first input is greater than a reference voltage on a second input and a second output state when the input voltage is less than the reference voltage;
• a current source configured to supply a hysteresis current to the first input of the comparator circuit in response to only one of the output states of the comparator circuit to be inactive otherwise;
• and
• a coupling circuit configured to couple a first reference voltage to the second input of the comparator circuit for a first predetermined time duration in response to a transition of the output voltage from the first output state to the second output state, and to couple a second reference voltage to the second input of the comparator circuit for a second predetermined time duration in response to a transition of the output voltage from the second output state to the first output state;
• wherein the first predetermined time duration is equal to the second predetermined time duration;
• and
• wherein the coupling circuit is further configured to couple a third reference voltage to the second input of the comparator circuit after the first predetermined time duration has expired.

A method for performing threshold comparison with hysteresis, comprising:

• providing, by a comparator circuit, an output voltage including a first output state when an input voltage on a first input is greater than a reference voltage on a second input and a second output state when the input voltage is less than the reference voltage;
• supplying, by a current source, a hysteresis current to the first input of the comparator circuit in response to only one of the output states of the comparator circuit, the current source being inactive otherwise;
• coupling, by a coupling circuit, a first reference voltage to the second input of the comparator circuit for a first predetermined time duration in response to a transition of the output voltage from the first output state to the second output state;
• coupling, by the coupling circuit, a second reference voltage to the second input of the comparator circuit for a second predetermined time duration in response to a transition of the output voltage from the second output state to the first output state, wherein the first predetermined time duration is equal to the second predetermined time duration;
• and
• coupling a third reference voltage to the second input of the comparator circuit after the first predetermined time duration has expired.