Hardware and methods for voltage and current sensing

A current sensor, comprising:

• a sense resistor coupled to receive an input current from a power source, wherein the sense resistor is formed from a plurality of connected elementary sense resistor units, wherein each of the plurality of connected elementary sense resistor units comprises a plurality of parallel metal sheets electrically connected in parallel to one another by vias;
• and
• an amplification circuit having:
• an amplifier having inputs across which the sense resistor is coupled and an output at which a voltage representative of the input current is produced;
• a first resistor coupled to at least one of the inputs of the amplifier, wherein the first resistor is formed from a plurality of connected elementary first resistor units surrounding the plurality of connected elementary sense resistor units on at least two sides, wherein each of the plurality of connected elementary first resistor units comprises a plurality of parallel metal sheets electrically connected in series to one another by vias;
• and
• a second resistor coupled to at least one of the inputs of the amplifier;
• wherein a gain of the amplification circuit is based upon a resistance of the second resistor and a ratio of a resistance of the sense resistor to a resistance of the first resistor;
• and
• wherein the first resistor and the sense resistor are formed from same materials in a same substrate and arranged in a ratiometric relationship such that the first resistor and sense resistor change temperature substantially equally during operation and such that the first resistor and sense resistor vary substantially equally in resistance over temperature.