DRV8874-Q1: Current mirror scaling error

Leandro Santos

Part Number: DRV8874-Q1

Hi, Technical resposible!

the technical specification of our application can be classified with this consumption range (IOUT < 0.4 A and 5.5 V ≤ VVM ≤ 37 V).

Could you confirm how I calculate the Analog current output proportional to load current with associated current mirror scaling error(AERR)?

Best regards

Leandro Santos

over 1 year ago

0 Ryan Kehr over 1 year ago

TI__Guru 54725 points

Leandro,

Please see this section in the datasheet for the basic calculation.

7.3.3.1 Current Sensing

At <0.4A, the error will be fixed per the footnote in the datasheet. So, after calculating the current using equations in the datasheet, the error on top of that will be +/-30mA.

If this is not precise enough for you, you can consider the following device that has an external sense resistor. You can read the voltage on sense pin, filter it, amplify it, etc to get a current reading.

https://www.ti.com/lit/ds/symlink/drv8872-q1.pdf

Regards,

Ryan

0 Leandro Santos over 1 year ago in reply to Ryan Kehr

Prodigy 10 points

Thank you for this technical summary, Rayan Kehr!

I will consider this error range on my current sensing solution.

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DRV8874-Q1: Current mirror scaling error