SBOS820A September 2019 – June 2020 TMCS1100
For room-temperature total-error calculations, specifications across temperature and drift are ignored. As an example, consider a TMCS1100A1 with a supply voltage (VS) of 3.3 V, a VREF of 1.5 V, and a worst-case common-mode excursion of 600 V to calculate operating-point-specific parameters. Consider a measurement error due to an external magnetic field of 30 µT, roughly the Earth's magnetic field strength. The full-scale current range of the device in specified conditions is slightly greater than 28 A; therefore, calculate error at both 25 A and 12.5 A to highlight error dependence on the input-current level. Table 1 shows the individual error components and RSS maximum total error calculations at room temperature under the conditions specified. Relative to other errors, the additional error from CMRR is negligible, and can typically be ignored for total error calculations.
|ERROR COMPONENT||SYMBOL||EQUATION||% MAX TOTAL ERROR AT IIN = 25 A||% MAX TOTAL ERROR AT IIN = 12.5 A|
|Input offset error||eIos||
|External Field error||eBext||
|Sensitivity error||eS||Specified in Electrical Characteristics||0.7%||0.7%|
|Nonlinearity error||eNL||Specified in Electrical Characteristics||0.05%||0.05%|
|RSS total error||eRSS||