Low temperature coefficient current sensor

A method of sensing or measuring a system current comprising:

• in response to a system current flowing between an input node and an output node via a first resistor, shunting a measurement current via a second resistor to a test node;
• measuring a voltage across the second resistor using an amplifier that is configured in a closed feedback loop to control the current through the second resistor in a manner that tends to reduce or minimize a voltage difference across first and second inputs of the amplifier;
• and
• wherein the measuring includes using thermally coupled first and second resistors wherein the second resistor comprises tap locations selectively coupled to the second amplifier input.

A system current sensor module for accurately performing at least one of a current sensing or measurement of a system current, the sensor module comprising:

• an input node, an output node, and a system current test node;
• a first resistor and a second resistor arranged in a feedback configuration to provide a gain (n) between a system load current and a test output current based on a ratio of resistance values of the first resistor and the second resistor wherein the second resistor comprises tap locations selectively coupled to a second amplifier input of a feedback amplifier having first and second amplifier inputs;
• and
• means for thermally coupling the first and second resistors to keep a temperature of the second resistor at or near a temperature of the first resistor when a system current is flowing through the first resistor and heating the first resistor.