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MSPM0G3519: MSPM0G3519

Parth Kamra
Prodigy 50 points
Part Number: MSPM0G3519
Other Parts Discussed in Thread: TXB0104

Tool/software:

Some questions in reference to above shown diagram in TI datasheet:

System Setup:

  • The MSPM0G3519 UART TX pin is configured as open-drain.

  •  The device to which TI G3519 is communicating has uart pin in push pull configuration (with a high-side PMOS).

  • A bidirectional level shifter (TXB0104) is placed between both devices, as TI MCU is running at +3.3V and EC200 4G module is runnung at 1.8V logic level.

  • The targeted baud rate is 1 Mbps.

Questions:

  1. Pull-Up Resistor Selection for Open-Drain TX:

    • Since the MSPM0G3519 is operating its TX in open-drain mode, what pull-up resistor value would you recommend for achieving reliable signal integrity at 1 Mbps UART baud rate?

  2. RX Line Considerations:

    • Will the pull up resistors be used on rx line of TI MCU open drain pin considering the TX line of other MCU to which it is connected has high side PMOS that is it is in push pull mode.

Attaching below the schematic for your reference
MSPM0G3519 SchematicLogic Shifter

  • 0
    TI__Mastermind 46765 points

    Hi,

    If it is still possible, I strongly suggest you to use other GPIO pins as UART function instead of using the open drain PA0 and PA1 IO. It could help you easily achieve a higher baud rate. 

    Considering the max sunk current by ODIO is 20mA. The Pull up resister should be higher than 3.3V/20mA = 165OHm. And since you want a higher baud rate, then the smaller the resister the better. 

    Best regards,

    Cash Hao