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US 12,451,874 B2Granted
Voltage comparator and method for comparing input voltages
AssigneeRenesas Design (UK) Limited
InventorJindrich Svorc
Life of this patent
Estimating the term…
Abstract
A voltage comparator includes a differential stage configured to provide a comparator current at an output node of the differential stage in dependence of a first input voltage at a first input node and a second input voltage at a second input node of the voltage comparator. The voltage comparator further includes a current comparator which is configured to provide an output voltage at an output node of the current comparator in dependence of the comparator current, and an output stage which is configured to provide an output signal of the voltage comparator in dependence of the output voltage at the output node of the current comparator.
Claims13
A voltage comparator which comprises,
- a differential stage configured to provide a comparator current at an output node of the differential stage in dependence of a first input voltage at a first input node and a second input voltage at a second input node of the voltage comparator;
- a current comparator having an input that is coupled with the output node of the differential stage;
- wherein the current comparator is configured to provide an output voltage at an output node of the current comparator in dependence of the comparator current,
- wherein:
- the current comparator is configured to limit a voltage swing of a voltage at the output node of the differential stage, which is caused by a change in polarity of the difference between the first input voltage and the second input voltage, to a limited value;
- and
- the limited value is 10% or less of a main supply voltage of the differential stage;
- and
- an output stage which is configured to provide an output signal of the voltage comparator in dependence of the output voltage at the output node of the current comparator;
- wherein the output signal is indicative on whether the first input voltage is greater or smaller than or equal to the second input voltage.
7 more elements
A voltage comparator which comprises:
- a differential stage configured to provide a comparator current at an output node of the differential stage in dependence of a first input voltage at a first input node and a second input voltage at a second input node of the voltage comparator;
- a current comparator having an input that is coupled with the output node of the differential stage, wherein the current comparator is configured to provide an output voltage at an output node of the current comparator in dependence of the comparator current,
- wherein the current comparator is configured to:
- couple the output node of the differential stage to a reference potential of the current comparator via a first follower transistor, if the comparator current has a first direction;
- and
- couple the output node of the differential stage to a current comparator supply voltage of the current comparator via a second follower transistor, if the comparator current has a second direction which is opposite to the first direction;
- and
- an output stage which is configured to provide an output signal of the voltage comparator in dependence of the output voltage at the output node of the current comparator, wherein the output signal is indicative on whether the first input voltage is greater or smaller than or equal to the second input voltage.
5 more elements
A voltage comparator which comprises:
- a differential stage configured to provide a comparator current at an output node of the differential stage in dependence of a first input voltage at a first input node and a second input voltage at a second input node of the voltage comparator;
- a current comparator having an input that is coupled with the output node of the differential stage;
- wherein the current comparator is configured to provide an output voltage at an output node of the current comparator in dependence of the comparator current;
- and
- an output stage which is configured to provide an output signal of the voltage comparator in dependence of the output voltage at the output node of the current comparator;
- wherein the output signal is indicative on whether the first input voltage is greater or smaller than or equal to the second input voltage,
- wherein:
- the differential stage is operated using a main supply voltage;
- the current comparator is operated using a current comparator supply voltage, which differs from the main supply voltage;
- and
- the output stage comprises level-shifting circuitry configured to shift the output voltage at the output node of the current comparator from the current comparator supply voltage to the main supply voltage to generate the output signal of the voltage comparator.
8 more elements
Dependencies are inferred from the claim text.