MSPM0C1103: PWM Output on 5V Tolerant Open-Drain Pins (PA0/PA1) of MSPM0C1103

DDdoor

Part Number: MSPM0C1103

Tool/software:

Hello,

I understand that PA0 and PA1 on the MSPM0C1103 are 5V tolerant open-drain pins.
If these pins are used for PWM output, is an external pull-up resistor required?

Best regards,

DDdoor

over 1 year ago

0 DDdoor over 1 year ago in reply to JOJO ARTHUR

Expert 2435 points

Thank you for your reply.

Does this mean that a pull-up resistor is required because the output becomes High-Z?

Best regards,
DDdoor

0 JOJO ARTHUR over 1 year ago

TI__Intellectual 1810 points

Hello,

Thank you for contacting us. Regarding PA0 and PA1, since they are 5V tolerant open-drain pins, even if used for PWM, an external pull-up resistor is needed in order to drive the output high. In the Typical Application section of the datasheet (9.1.1), the open-drain IOs is connected to an external pull-up resistor hence indicating that as a requirement. Kindly let me know if you have further questions or concerns.

MSPM0C1103 Datasheet: https://www.ti.com/lit/ds/symlink/mspm0c1103.pdf

Regards, Jojo

0 JOJO ARTHUR over 1 year ago in reply to DDdoor

TI__Intellectual 1810 points

Hello DDoor,

Exactly. This is because the open-drain outputs either actively pull the line low or leave it in a high impedance state. When it's in the High-Z state, it's effectively disconnected so without the pull-up resistor, the voltage on the line would be undefined or floating.

Regards, Jojo

+1 JOJO ARTHUR over 1 year ago in reply to DDdoor

TI__Intellectual 1810 points

Hello DDdoor,

Hope you are having a good day. Nevertheless, just checking if further assistance is needed on this. If not, kindly let me know as well.

Regards, Jojo

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MSPM0C1103: PWM Output on 5V Tolerant Open-Drain Pins (PA0/PA1) of MSPM0C1103