Connect the output of one INA28x-Q1 family device to the reference input of the second INA28x-Q1 family device. The reference input of the first circuit sets the reference at the output. This circuit example is identical to the current summing example, except that the two shunt inputs are reversed in polarity. Under normal operating conditions, the final output is very close to the reference value and proportional to any current difference. This current differencing circuit is useful in detecting when current into and out of a load do not match.