Low-Side Current Sensing

The following image shows a schematic for a low-side current sensing circuit that can be connected to an ADC. This can be used for applications such as brushed/BLDC motor phase current measurement (see the BLDC Motor Control page). It uses a current sense resistor on the low side of the current path (i.e., next to ground) and then shifts the result away from the rails to Vcc/2 for better precision/compatibility with ADC’s.