DRV8871: Logs of current consumption

May

Part Number: DRV8871
Other Parts Discussed in Thread: DRV8870, DRV8872

Hi,

Customer want to know, can they take logs of current consumption by motor on MCU using current regulation (ILIM) or current sense pin (ISEN) of motor drivers like DRV8871,72,70.

Regards,
Maynard

over 4 years ago

0 Pablo Armet over 4 years ago

TI__Mastermind 37683 points

Hi Maynard,

You can definitely do that. For the DRV8870, you will need an external amplifier from ISENSE to the MCU to amplify the signal. For the DRV8871 and DRV8872 with ILIM, you can connect ILIM directly to an ADC channel of MCU to read and log the motor current.

0 May over 4 years ago in reply to Pablo Armet

TI__Genius 9880 points

Hi Pablo,

I just received a response from customer, below is the details.

unable to read the current on ILIM pin of DRV8871 no values are showing i have tried with resistor across resistor without resistor but no values are showing even on multi meter

Regards,
Maynard

0 Pablo Armet over 4 years ago in reply to May

TI__Mastermind 37683 points

Hi Maynard,

What is the current the customer is trying to measure and what is the resistor value/s they are using? If you have a schematic you can share, that'll be better. You can share the schematic via private message if you don't want to share publicly.

0 May over 4 years ago in reply to Pablo Armet

TI__Genius 9880 points

Hi Pablo,

Below is the schematic

Regards,
Maynard

0 Pablo Armet over 4 years ago in reply to May

TI__Mastermind 37683 points

Hi Maynard,

The schematic looks good. The ILIM resistor is within our minimum recommended value. Are you having this issue with more than one IC?

0 May over 4 years ago in reply to Pablo Armet

TI__Genius 9880 points

Hi Pablo,

According to the customer, they are having issue more than one IC.

Regards
Maynard

0 Pablo Armet over 4 years ago in reply to May

TI__Mastermind 37683 points

Hi Maynard,

Thank you for the information.

I realized I made a mistake on my previous reply. Is it NOT possible to monitor the H-bridge current on the ILIM pin of the DRV8871. Apologies for the confusion.

The DRV8870 and DRV8872 can be used for current monitoring using the external sense resistors with a current sense amplifier.

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DRV8871: Logs of current consumption