Current sense amp for shunt monitoring
The TSC103IDT is a single-circuit current sense amplifier from STMicroelectronics, designed to measure current through an external shunt resistor and output a proportional voltage. It targets applications where a low-side or high-side shunt voltage must be amplified and fed to an ADC or comparator — typical in motor-phase current monitoring, solenoid diagnostics, or power-rail load detection. The 200 µA supply current makes it suitable for always-on sense circuits where quiescent draw matters — battery-monitoring or energy-harvesting nodes, for example.
Supply rails and input offset budget
The 500 µV maximum input offset voltage sets the DC error floor — for a 10 mΩ shunt carrying 1 A, the 10 mV sense signal sees a 5 % offset error before any gain-stage contribution. Input bias current is 10 µA typical. This current flows through the shunt and the sense resistors, adding a systematic offset that must be accounted for in the gain equation — particularly with low-value shunts where the bias current drop becomes a significant fraction of the sense voltage. The output can source or sink 26 mA per channel, enough to drive the input of a typical SAR ADC or a comparator directly without a buffer stage.
This allows deployment in under-hood electronics, engine-bay sensors, or outdoor industrial enclosures without a temperature derating step.
The part is RoHS3 compliant (2011/65/EU + 2015/863), meeting the current European hazardous-substance restrictions for electronic equipment.