The INA790x features an integrated EZShunt™ technology current-sensing resistor that provides accurate measurements over the entire specified temperature range of –40°C to +125°C. The integrated current-sensing resistor provides measurement stability over temperature, and simplifies printed circuit board (PCB) layout and board constraint difficulties common in high-precision measurements.

The onboard current-sensing resistor is designed as a 4-wire (or Kelvin) connected resistor that enables accurate measurements through a force-sense connection. Internally connected amplifier input pins (IN– and IN+) to the sense pins of the shunt resistor eliminates many instances of parasitic impedance commonly found in typical very-low sensing-resistor level measurements. The INA790x is system-calibrated to make sure that the current-sensing resistor and current-sensing amplifier are both precisely matched to one another. The in-package integrated sensing resistor must be used with the internal current-sensing amplifier to achieve the optimized system gain specification.

The INA790x has approximately 550µΩ of package resistance. Of this total package resistance, 400µΩ resistance from the Kelvin-connected current-sensing resistor is used by the amplifier. The power dissipation requirements of the system and package are based on the total 550µΩ package resistance between the IS+ and IS– pins.

Figure 6-1 IS+ to IS– Package Resistance vs Temperature