Compensating current monitor for electronic systems having mode-sensitive selection of current-sensing inputs

Accurate operation of a current monitor is provided by injecting a bias voltage to a maintain de-selected sense amplifier input in an active state. An electronic system includes an output stage to supply a load current and includes two push-pull output drivers P1, N1, P2, N2 having sense resistors RS1, RS2 supplying a first and a second sense voltage. A mode control circuit 37 selects between a first and a second operating mode and selects a polarity of the current. A current monitor 30 receives the sense voltages and has a control input coupled to the mode selection control circuit. The current monitor provides an output that is dependent on both sense voltages in the first operating mode and is indicative of one of the sense voltages selected according to the selected polarity in the second operating mode. The bias voltage is injected into an unselected sense inputs to maintain active operation of the sense amplifier A3, A4. The arrangement may be used with motor drivers and other power output electronics, such as haptic drivers that have selectable operating modes.