DRV8316: DRV8316 Ioffset_Current sense offset low side current in of CSA

Hollis Liu

Part Number: DRV8316

Hi team,

i would like to know how do we test the I_offset which is in datasheet. i suppose that we set a fix gain, and set input to be 0, and test the output, right? What's the status of OUTX and high side/low side MOSFET?

Thanks.

over 3 years ago

0 Anthony Lodi over 3 years ago

TI__Mastermind 22086 points

Hi Hollis,

Thank you for your post!

I will try to get back to you tomorrow on this.

Regards,

Anthony

+1 Anthony Lodi over 3 years ago

TI__Mastermind 22086 points

Hi Hollis,

Here is a step by step on how to test this value:

1. Set a fixed gain, Gcsa
2. Ensure that all MOSFETs are off except for the low side MOSFET of the channel that is being measured (this is done by applying INLx = 1 for the x phase that is being measured and making sure all the other INHx and INLx pins = 0). This will result in OUTx of the measured phase being approximately 0V since turning on the low side MOSFET will pull the OUTx node to ground.
3. With no current applied to the phase, measure the SOx output voltage as well as the CSAREF voltage.
4. Calculate the I_offset current.
since SOx (at 0A phase current) = CSAREF/2 + (Gcsa x I_offset), then
I_offset = (SOx - CSAREF/2) / Gcsa

Steps 1-4 can be repeated for each phase to calculate the I_offset for each phase.

Regards,

Anthony Lodi