Sendyne's SFP101 current, voltage and temperature measurement IC and board achieves a maximum voltage offset error of less than ±150 nV (±0.15µV) for the measurements of the voltage drop across a shunt. Further, the SFP101 provides user-definable automatic compensation for resistance dependence of the shunt on temperature from -40°C to +125°C, and is programmable to accommodate shunts with an output voltage from ±10mV to ±300mV. This means that the SFP101 can work with a shunt of essentially any resistance made from any material.
For example, a copper busbar can have as large as a 35% error over temperature, making it unsuitable for use in exact current measurement. Due to the proprietary temperature compensation feature of the SFP101, that error is typically reduced to ±0.1%.
Using a 25 mW or 100 mW shunt, the SFP101 typically achieves ±0.05% accuracy of current measurements. A 25 mW shunt, such as those produced by Vishay, can now be used for high power applications, handling continuous currents of 300A and peak currents of 2000A while resolving currents as small as 250µA.
These specifications are not derived from theoretical calculations: they represent the actual performance of the entire measurement system, including thermocouple errors in the connections and EMI filter, verified through extensive lab testing with several types of shunts.
In addition, the SFP101 provides on-board calibration for both current and voltage, storing calibration values and applying them internally, offers separate charge, discharge, and total Coulomb counters and measures multiple temperature points to ±1°C.
