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SN6505A: Can SN6505A EN pin be driven with MCU GPIO?

Part Number: SN6505A

Hi ISO team, 

I'm posting this question on behalf of my customer.

Can the input enable pin be driven directly with a GPIO from an MCU (sits at 3.3V)?

Thank you for your response,


  • Hi Lauren,

    The SN6505 enable pin can be driven directly by an MCU GPIO as long as the logic high voltage level is > or = 0.7 x Vcc.

    If Vcc in our customer's system = 3.3V, then this GPIO (or a GPIO signal down to ~2.3V!) can control the enable pin. If our customer's supply voltage = 5V, then 3.3V will not suffice. An enable signal of at least 3.5V would be necessary.

    Thank you for posting to E2E! Does this response cover our customer's case?

    Manuel Chavez
  • Hi Manuel,

    Yes it does - there was some confusion on both our parts (mine and the customer's) because in the datasheet it states 0.7Vcc is the max voltage that will allow the enable pin to turn on (page 6). So I read it as the enable pin will be enabled between 0.3Vcc to 0.7Vcc.

    For my learning, and for future reference for others, could you provide a little more clarification on what that means? If enable pin isn't enabled until voltage is 0.7Vcc, what happens right above 0.3Vcc, and below 0.3Vcc?

    Thank you,
  • Lauren,

    When the Enable voltage level is below 0.3xVcc, the SN6505 is guaranteed to be disabled. Between 0.3xVcc and 0.7xVcc, the enable thresholds vary from device to device. Only the minimum and maximum values are specified for clarity and usefulness.

    Are there additional questions I can help answer?

    Thank you for your time,
    Manuel Chavez
  • Hi Manuel,

    No, thank you, that answers my question.

    Thank you very much for your assistance!



  • Hi Lauren,

    You're welcome! We're glad to help. Please feel free to click the green "This resolves my issue" button to close this thread.

    Have a great week,
    Manuel Chavez