Current sensor

A current sensing device comprising:

• a die;
• a shunt resistor having a first terminal and a second terminal and fabricated onto the die, wherein the shunt resistor is fabricated from a first material having a first temperature coefficient;
• a first compensation resistor fabricated onto the die, the first compensation resistor having a first terminal coupled to the first terminal of the shunt resistor and having a second terminal, wherein the first compensation resistor is located proximate the shunt resistor and is maintained at approximately the same temperature as the shunt resistor by way of its proximity, and wherein the first compensation resistor has a temperature coefficient that is approximately equal to the temperature coefficient of the shunt resistor;
• a second compensation resistor fabricated onto the die, the second compensation resistor having a first terminal coupled to the second terminal of the shunt resistor and having a second terminal, wherein the second compensation resistor is located proximate the shunt resistor and is maintained at approximately the same temperature as the shunt resistor by way of its proximity, and wherein the second compensation resistor has a temperature coefficient that is approximately equal to the temperature coefficient of the shunt resistor:
• and
• a voltage-to-current converter including:
• a differential amplifier having first and second inputs and having an output, wherein the first input is coupled to the second terminal of the first compensation resistor, and the second input is coupled to the second terminal of the second compensation resistor and to a reference current terminal;
• a switch having a control terminal coupled to the output of the differential amplifier, and a switch output providing a sense current in response to voltages at the first and second inputs of the differential amplifier;
• and
• a current-to-voltage amplifier having:
• a first current input coupled to the switch output;
• a second current input coupled to a reference current source;
• an output providing a voltage indicative of the current through the shunt resistor;
• a first feedback resistor coupled between the first current input and the output;
• and
• a second feedback resistor coupled between the second current input and the output.