TLIN1029-Q1: Question of external pull up

Lee, Sam

Expert 6235 points

Part Number: TLIN1029-Q1

Hi team,

I just want to double check wheterh the external pull up can be removed between TLIN1029-Q1 and MCU.

The MCU has an internal pull up (13kohm), so is it okay to remove the external pull-up resistor on RXD pin path?

Thanks,

Sam Lee

over 7 years ago

0 Eric Hackett over 7 years ago

TI__Guru 74352 points

Sam,

The recommended external pull-up is typically 5k-10k ohms, but a 13k ohm pull-up should be sufficient.

Regards,

0 Miguel Robertson over 7 years ago in reply to Eric Hackett

TI__Guru 62920 points

Sam,

I agree with Eric that 13 kOhm is likely fine. If you want to read more on how to determine the maximum pull-up resistance that can be supported via an open-drain signal, though, you may want to refer to this application note:

www.ti.com/.../slva689.pdf

It is written specifically for I2C, but the same concepts would apply to any open-drain signals.

Max

0 Lee, Sam over 7 years ago in reply to Miguel Robertson

TI__Expert 6235 points

Hi Max, Eric,

Thank you for your kind answer.

Best Regards,

Sam Lee

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TLIN1029-Q1: Question of external pull up