DRV8837: Current Consumption

Ricardo Dias1

Part Number: DRV8837
Other Parts Discussed in Thread: SN74AHC1G32,

Hi everyone,

Nowadays I'm working on a project with a TI driver motor whose part number is DRV8837DSGR.

The thing is that when I assembled the board and test it everything was fine, all circuit works at all and the general current consumption was about 800uA. After a batterie of tests I take some current measures again to confirm the previous measured value, and for my surprise the value changes, and changes a lot but the circuits continue to works as it should.

Following is the schematic part of the driver (Obs U11 actual PN is SN74AHC1G32 that is 5V tolerant).

I already investigated all the circuit, desassembling IC by IC from board to find where are the problem. For my surprise the problem was DRV8837. As you can see in the images below.

Do you guys have an idea about what could beeing happend here?

Please if you need any further informmation please contact me.

Thanks in advance.

over 5 years ago

0 Hector Hernandez Luque over 5 years ago

TI__Expert 8985 points

Hi Ricardo,

I cannot see the images you shared. Can you reshare again? Thank you.

0 Ricardo Dias1 over 5 years ago in reply to Hector Hernandez Luque

Prodigy 75 points

Follow are the images posted initially. Thank you.

0 Ricardo Dias1 over 5 years ago in reply to Hector Hernandez Luque

Prodigy 75 points

Hi Hector.

Thank you for reply.

Follow are the images posted initially. Thank you.

0 Hector Hernandez Luque over 5 years ago in reply to Ricardo Dias1

TI__Expert 8985 points

Hi Ricardo,

Thank you.

What supply's current is being measured, VM?

What test led to the current draw increasing?

How many different boards have shown this behavior?

If possible, please share the layout file (pdf or .pcb file acceptable). I will open a private sharing conversation if private sharing is required.

0 Ricardo Dias1 over 5 years ago in reply to Hector Hernandez Luque

Prodigy 75 points

Hi Hector,

We change C15 capacitor value to 10uF and are testeing the board since last Friday, was more than 180h of tests and seems that your recommendation resolved the problem.

I just like to understand more what causes this problem, Can you explain a litle bit more about this issue?

Thank you in advance.

Best Regards.

Ricardo.

0 Hector Hernandez Luque over 5 years ago in reply to Ricardo Dias1

TI__Expert 8985 points

Hi Ricardo,

That is very good news to read.

Please, read section 9.1 Bulk Capacitance of the datasheet. It gives well-written reasoning as to why the bulk capacitance to the driver/FETs is essential to motor drive designs.

0 Ricardo Dias1 over 5 years ago in reply to Hector Hernandez Luque

Prodigy 75 points

Thank you Hector,

Your support was definitly important to resolve this issue.

Thank you for these tips.

Best Regards.

Motor drivers

Motor drivers forum

DRV8837: Current Consumption