For motor control, I need to monitor its current. Can a simple low side shunt be used for measurement, or will the offset voltage (no direct GND connection) cause problems?
Electronic – Integrated H-Bridge (ST VNH3SP30-E) suitable for low-side current-sensing
current measurementh-bridgesensor
Related Topic
- Measuring current using low side shunt method (MCLV-2 board)
- Electronic – High side current indicator/
- Electrical – Why is bi-directional current sensing required in sensorless BLDC field-oriented-control
- Electrical – Measure current for Field Oriented Control
- Electronic – H-bridge low side current sensing: Current signal with oscillation why
- H-Bridge – Op-Amp Current Sense in H-Bridge
Best Answer
You don't say how much current the motor needs, but because it uses Hall effect instead of a shunt resistor this sensor (ACS712) has a very low internal resistance of 1.2 mΩ. That's only 12 mV drop at 10 A. Sensitivity up to 185 mV/A.
Notice also that the high current path is galvanically isolated from the signal ground in this sensor. That can solve the ground offset problem. IP- may be connected to power ground, while GND can be connected to signal ground. VIOUT will be referenced to GND.