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Visitor II
May 20, 2024
Question

STM32G491 Pin1 Marking

  • May 20, 2024
  • 5 replies
  • 3111 views

Hey, i

 

got this STM32G491MET6

The datasheet does not really help here to identify pin 1, since there are 4 markings to see. Anyone has a clue on this? In the previous revision of this datasheet, Pin 1 is bottom left . Already burnt 2 mcus because of this...

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    5 replies

    Graduate II
    May 20, 2024

    Smaller circle, bottom left. The others are molding / ejector related.

    ST prints the text in top-to-bottom, left-to-right western form. Held in a readable fashion the Pin 1 designation is down and to the left.

    IMG_3502_pin1.jpg

    Graduate II
    May 20, 2024

    My expectation is that legitimate parts will have a common VSS bonding, which you could continuity check to confirm orientation expectations.

    Could perhaps look for other boards, orientation, where VCC and GND enter, HSE placed, SWDIO/SWCLK and VCAPs (where used)

    stm32g491me_lqfp80_001.jpg

    Super User
    May 20, 2024

    This appears to be a regression in rev4 of the DS:

    waclawekjan_0-1716224695693.png

    waclawekjan_1-1716224725060.png

    @Imen.D, can you please have a look at this? Thanks.

    JW

    Technical Moderator
    May 23, 2024

    Hi @waclawek.jan,

    All device markings are being removed from the Datasheet and are being moved to the Technical note: Reference device marking schematics for STM32 microcontrollers and microprocessors.

     

    Graduate II
    May 23, 2024

    Someone should also have a word with the graphics dept.. about unhelpful imagery

    stm32_trust_g0_pin1.jpg

    Super User
    May 23, 2024

    Hi @Imen.D ,

    Okay, and is/will be there a link/pointer to that document in the datasheets themselves, or is it upon us to spread the gospel?

    Thanks,

    Jan

     

    Graduate II
    May 23, 2024

    On most ICs, the bottom row of the label contains the first pin.

    Graduate II
    May 23, 2024

    Which is great advice until it's not..

    mc68882fn16a.jpg

    You should have a conversation with my pick-n-place guy some day..

    Graduate II
    May 23, 2024

    I've never encountered an IC labeled like this before. Until you showed me this picture, I believed there was a standard for IC naming that I didn't know about.