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DRV8106-Q1: Current sense Accuracy for DRV8106-Q1

Rama Y
Prodigy 10 points
Part Number: DRV8106-Q1
Other Parts Discussed in Thread: TPS7B81-Q1

Tool/software:

Hello Team,

We are planning to use the DRV8106-Q1 in our design to drive an inductive load. According to the datasheet, it has an input offset voltage of +/- 3.5 mV at 105°C and a current sense gain error of 2%. Of course, input bias current and Reference voltage (has 1.5% accuracy with TPS7B81-Q1) will also contribute to current sense accuracy. 

Given that our load current ranges from 7 A to 30 A, does TI offer any calibration mechanism or recommended approach to compensate or correct for current sense errors?

Thank you, 

Rama

  • +1
    TI__Mastermind 45035 points

    Hi Rama,

    Thank you for your post.

    Rama Y said:
    Given that our load current ranges from 7 A to 30 A, does TI offer any calibration mechanism or recommended approach to compensate or correct for current sense errors?

    I assume you'll be reading the CSA output with an ADC of an MCU. The CSA should output AREF/2 with VSP-SN = 0 V or zero current via the sense resistor. You can do a zero calibration under this condition at the ambient temperature of the application. Next would be gain calibration for a specific gain setting of the CSA for each of the gain settings that will be used in the application. This can be done by using a desired load current in the mid-point of the input range for that gain setting for a one point gain calibration. If higher accuracy is desired you can do a two point calibration by picking two current values within the range for that gain setting. Thank you.

    Regards, Murugavel