For room-temperature total-error calculations, specifications across temperature and drift are ignored. As an example, consider a TMCS1100-Q1A1 with a supply voltage (V_S) of 3.3 V, a V_REF 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 10-1 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.

Table 10-1 Total Error Calculation: Room Temperature Example

ERROR COMPONENT	SYMBOL	EQUATION	% MAX TOTAL ERROR AT IIN = 25 A	% MAX TOTAL ERROR AT IIN = 12.5 A
Input offset error	eIos		0.24%	0.48%
PSRR error	ePSRR		0.27%	0.54%
CMRR error	eCMRR		0.01%	0.02%
VREF error	eVREF		0.04%	0.08%
External Field error	eBext		0.11%	0.22%
Sensitivity error	eS	Specified in Section 7.9	0.7%	0.7%
Nonlinearity error	eNL	Specified in Section 7.9	0.05%	0.05%
RSS total error	eRSS		0.88%	1.28%