BOOSTXL-DRV8305EVM: Trouble getting ISENA to work properly and convert to current with LAUNCHXL-F28937D

Kristian Eoll

Tool/software:

Hello, I'm currently working on a project where I need to use the ISENA pin to obtain the current going through the shunt on bridge A. I'm driving the coil with a PWM signal from the microcontroller. An issue I'm facing is that although the current changes, the voltage I'm getting from the ISENA pin does not change.

Thank you, Kristian

28 days ago

0 Kristian Eoll 28 days ago

Prodigy 60 points

For a little more clarification, If I change the PWM signal it will change, but if the current drops from lets say 4.5 to 4 amps due to the resistance of the coil increasing, the voltage of the pin wont change

0 Yara Al Shami 24 days ago in reply to Kristian Eoll

TI__Genius 15025 points

Hi Kristian,

What gain setting are you using? How are you measuring ISENA? Are you using the GUI?

Regards,

Yara

0 Kristian Eoll 23 days ago in reply to Yara Al Shami

Prodigy 60 points

Hello Yara, I'm using a gain of 10 V/V, and I'm measuring ISENA with a LAUNCHXL-F28937D board and reading the pin with a Oscilloscope.
Thank you,

Kristian

0 Yara Al Shami 15 days ago in reply to Kristian Eoll

TI__Genius 15025 points

Hi Kristian,

Do you happen to have waveforms of the input and put signals of the CSA? you might have to probe the sense resistor of the input.

Have you tried changing the GAIN, does the same behavior occur?

Regards,

Yara

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BOOSTXL-DRV8305EVM: Trouble getting ISENA to work properly and convert to current with LAUNCHXL-F28937D