A method for adjusting common mode rejection ratio (CMRR) and gain error of a current sense (CS) amplifier, comprising: measuring a first referred to input (RTI) offset voltage while presenting a given common mode (CM) input voltage; adding a first trim resistor of a plurality of selectable trim resistors within an adjustable feedback resistor chain to a feedback electrical path; measuring a second RTI offset voltage while presenting the given CM input voltage; estimating, based upon the first and second RTI offset voltages, a third RTI offset voltage value that would result by adding a second trim resistor of the plurality of selectable trim resistors to the feedback electrical path; using the first, second and third RTI offset voltage values to identify the combination of selectable trim resistors that achieves an RTI offset voltage closest to zero volts; and adding the identified selectable trim resistors to the feedback electrical path.