TPS62148: Behavior for back electromotive force

Sadanori Kato

Part Number: TPS62148

Hi,

The output voltage rises up to the input voltage by the back electromotive force which is generated when the dc motor which is the output load for TPS62148 is suddenly turned off with the forced PWM mode.
At this time, the FB voltage also rises, SW voltage almost matches the output voltage and it seems that the high side and low side FETs turn off when the SW voltage is monitored.
As a result, the output voltage doesn't return to the expected voltage.
So, could you please tell me why TPS62148 behaves like this and how to protect TPS62148 from the back electromotive force?

Best regards,
Kato

over 3 years ago

0 Amod Vaze over 3 years ago

TI__Mastermind 23800 points

Hi Kato-san,

Can you share some more details like schematic, input voltage that is being applied and how much output voltage is being generated by the back emf? Are there any waveforms that you can capture showing VIN, VOUT, VSW during this event?

Thanks,
Amod

0 Sadanori Kato over 3 years ago in reply to Amod Vaze

Guru 36510 points

Hi Amod-san,

Thank you for your prompt reply.

I can share them with you via a private message. So, could you please accept my friendship request?

Best regards,
Kato

+1 Amod Vaze over 3 years ago in reply to Sadanori Kato

TI__Mastermind 23800 points

Hi Kato-san,

I have sent you my email. Please send me the information via email.

Regards,

Amod

0 Sadanori Kato over 3 years ago in reply to Amod Vaze

Guru 36510 points

Hi Amod-san,

Thank you for your response.

I just sent you the detailed information via an email.

Best regards,
Kato

0 Sadanori Kato over 3 years ago in reply to Sadanori Kato

Guru 36510 points

Hi Amod-san,

Sorry for rushing you.

Did you receive my email? If not, please let me know.

Best regards,
Kato

0 Ruby Li over 3 years ago in reply to Sadanori Kato

TI__Expert 7430 points

Hi Kato-san,

Amod is looking into this and will feedback to you soon.

Ruby

0 Amod Vaze over 3 years ago in reply to Sadanori Kato

TI__Mastermind 23800 points

Hi Kato-San,

yes I replied to your email.

Thanks,

Amod

0 Sadanori Kato over 3 years ago in reply to Amod Vaze

Guru 36510 points

Hi Amod-san,

Thank you for your reply.

I just sent an email to you, so please check it again.

Best regards,
Kato

0 Lishuang Zhao over 3 years ago in reply to Sadanori Kato

TI__Expert 7500 points

Hi Kato,

So we will close this thread.

Thanks

0 Sadanori Kato over 3 years ago in reply to Lishuang Zhao

Guru 36510 points

Hi Lishuang-san,

I understand.

Best regards,
Kato

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TPS62148: Behavior for back electromotive force