JAJSRU9 October 2023 TMCS1133
ADVANCE INFORMATION
Offset error is the deviation from the ideal output with zero input current flowing through the current sensor and most often limits measurement accuracy at low input current levels. Offset error can be referred to the output as offset voltage error or referred to the input as offset current error. When divided by device sensitivity, S, output voltage offset error VOE is input referred as input current offset error IOS (see Equation 4). Offset error referred to the input (RTI) allows for more direct comparisons or offset error with input current. Regardless of whether offset error is referred to the input as current offset error IOS, or to the output as voltage offset error VOE, offset error is a single error source and should only be included once in either input referred, or output referred error calculations.
The output voltage offset error VOE of the TMCS1133 is the difference between the zero current output voltage VOUT,0A and the zero current output reference voltage VREF (see Equation 5).
The output offset error VOE includes magnetic offset error in the Hall sensor, offset voltage error in the signal chain, and offset error in the internal zero current output reference voltage VREF.
Offset drift is the change in the offset as a function of temperature, T. Output offset drift is reported in µV/°C. To calculate offset error at any given temperature, multiply the offset drift by the change in temperature and add it to offset error at 25°C (see Equation 6).
where