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MCP809: /RESET pin behavior while VCC<1.0V

Tamio Yokokura
Expert 3640 points
Part Number: MCP809
Other Parts Discussed in Thread: TLV809

Hello, MCP809 support team

I have three question on MCP809.

  1. What is POR threshold voltage? Is it 1.0V?
  2. What is the output type of /RESET pin? Open-drain or Push-Pull?
  3. When /RESET pin is pulled up to VCC via 100kΩ, Which of #1 and #2 is correct behavior as /RESET pin? As far as I see the Pin Description, I think it looks like /RESET #2.           

            

             

Regards,

Tamio

  • 0
    TI__Expert 4890 points

    Hi Tamio,

    Thanks for your question. 

    Vpor is the lowest supply voltage that RESET becomes valid, and for MCP809 it is specified as RESET Output Valid for VCC≥1V in the datasheet. Before supply voltage pass Vpor threshold, it is undefined. 

    And if you look at the product page, the device output topology is descried as push-pull. 

    The timing diagram you are referring is not in MCP809 datasheet. Please find the expected output behavior is defined in the pin description table. 

    For just clarification your question, the reset behavior is the same for that timing diagram when VDD is higher than Vpor threshold. 

    MCP809 is an old device, I would recommend checking TLV809 supervisor family as well. I hope this helps! 

    Best,

    Sila 

  • 0 in reply to Sila Atalar
    TI__Expert 3640 points

    Hi, Sila,

    I wanted to know how the MCP809 behaves when VDD<VAPOR, so I'm glad to find out that the behavior of the MCP809 when VDD<VPOR is undefined, just like other VRS devices.

    As a result, I understood MCP809 also is RESET_#2

    Thanks

    Tamio