The INA234 integrates a low offset 12-bit delta-sigma (ΔΣ) ADC. This ADC is multiplexed to process both the shunt voltage and bus voltage measurements. Bus voltage measurements are made with respect to IN– and GND. The shunt voltage measurement is a differential measurement of the voltage developed when the load current flows through a shunt resistor as measured between the IN+ and IN– pins. The shunt voltage measurement has an maximum offset voltage of only 100 µV and a maximum gain error of 0.5%. The low offset voltage of the shunt voltage measurement allows for increased accuracy at light load conditions for a given shunt resistor value. Another advantage of low offset is the ability to sense a lower voltage drop across the sense resistor accurately, thus allowing for a lower-value shunt resistor. Lower-value shunt resistors reduce power loss in the current-sense circuit and help improve the power efficiency of the end application.

There are no special considerations for power-supply sequencing because the bus common-mode at the IN+ and IN– pins and power-supply voltage at the vs. pin are independent of each other; therefore, the bus common-mode voltage can be present with the supply voltage off, and vice-versa.