Current sensing circuit
AssigneeSTMicroelectronics S.r.l.
InventorPaolo Angelini
Life of this patent
Estimating the term…
Abstract
In accordance with an embodiment, a method of measuring a load current flowing through a current measurement resistor coupled between a source node and a load node includes: measuring a first voltage across a replica resistor when a first end of the replica resistor is coupled to the source node and a second end of the replica resistor is coupled to a reference current source; measuring a second voltage across the replica resistor when the second end of the replica resistor is coupled to the source node and the first end of the replica resistor is coupled to the reference current source; measure a third voltage across the current sensing resistor; and calculating a corrected current measurement of the load current based on the measured first voltage, the measured second voltage and the measured third voltage.
Claims20
A current sensing circuit comprising:
- a current sensing resistor coupled between a source node and a load node;
- a replica resistor having a same temperature behavior as the current sensing resistor;
- a voltage measurement circuit coupled to the current sensing resistor and the replica resistor, the voltage measurement circuit configured to:
- measure a first voltage across the replica resistor in response to a first end of the replica resistor being coupled to the source node and a second end of the replica resistor being coupled to a reference current source,
- measure a second voltage across the replica resistor in response to the second end of the replica resistor being coupled to the source node and the first end of the replica resistor being coupled to the reference current source, and
- measure a third voltage across the current sensing resistor;
- and
- a correction circuit coupled to the voltage measurement circuit and configured to produce a corrected current measurement value indicative of a current flowing through the current sensing resistor based on the measured first voltage, the measured second voltage, and the measured third voltage.
A device, comprising:
- an electrical load;
- and
- a current sensing circuit, comprising:
- a current sensing resistor coupled between a source node and a node of the electrical load,
- a replica resistor having a same temperature behavior as the current sensing resistor,
- a voltage measurement circuit coupled to the current sensing resistor and the replica resistor, the voltage measurement circuit configured to:
- measure a first voltage across the replica resistor in response to a first end of the replica resistor being coupled to the source node and a second end of the replica resistor being coupled to a reference current source;
- measure a second voltage across the replica resistor in response to the second end of the replica resistor being coupled to the source node and the first end of the replica resistor being coupled to the reference current source;
- and
- measure a third voltage across the current sensing resistor, and
- a correction circuit coupled to the voltage measurement circuit and configured to produce a corrected current measurement value indicative of a current flowing through the current sensing resistor based on the measured first voltage, the measured second voltage, and the measured third voltage.
A method, comprising:
- measuring, by a voltage measurement circuit, a first voltage across a replica resistor in response to a first end of the replica resistor being coupled to a source node and a second end of the replica resistor being coupled to a reference current source, a current sensing resistor being coupled between the source node and a load node, a replica resistor having a same temperature behavior as the current sensing resistor, the voltage measurement circuit being coupled to the current sensing resistor and the replica resistor;
- measuring, by the voltage measurement circuit, a second voltage across the replica resistor in response to the second end of the replica resistor being coupled to the source node and the first end of the replica resistor being coupled to the reference current source;
- and
- measuring, by the voltage measurement circuit, a third voltage across the current sensing resistor;
- and producing, by a correction circuit coupled to the voltage measurement circuit, a corrected current measurement value indicative of a current flowing through the current sensing resistor based on the measured first voltage, the measured second voltage, and the measured third voltage.
Dependencies are inferred from the claim text.