SBOA536 December 2021 INA240
A return path must be provided for the input bias current of non-isolated current sensors. This is normally done by sharing the same ground with the source being sensed. Through circuit techniques such as level shifting, it is possible to adopt current-sense amplifiers for high-voltage applications which are otherwise impossible. For motor drive current sensing, it is important to identify the suitable current sensor for the topology, recognizing voltage and timing requirements. PCB layout is just as important as the schematic design itself. It is critical to optimize component placement, minimized recirculating current loop, and provide solid ground planes. Follow best practices to reduce parasitic and interference, thereby reducing overvoltage and undervoltage spikes for the current sensor.