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TPIC6C595: recommended high level

user4366237
Prodigy 120 points
Part Number: TPIC6C595
Other Parts Discussed in Thread: TLC6C598, , TLC6C598-Q1, TLC6C5816-Q1

Hello,

We use currently the TLC6C598 in a product, but it is currently unavailable.
We have a 3.3V logic for SER IN and RCK.
In the datasheet the recommended high level is >0.85 VCC (about 4.25V).
At room temperature the TPIC6C595 works also with a high level of 3.3V.


Have you data about the save high level over part to part and temperature diversification?

Thank you so much,

Kilian Hüttenhofer

  • 0
    TI__Expert 5380 points

    Hi Kilian,

    What do you mean the device is not available? If you can' t request the sample for TLC6C598, you can request TLC6C598-Q1 samples. They are the same.

    TPIC6C595 can only support 5V power supply, 3.3V VCC is not ok for TPIC6C595.

  • 0 in reply to Anda Zhang
    Prodigy 120 points

    We are currently in mass production. But our supplier didn't bought the TLC6C598 either the TLC6C598-Q1. We need about 20k in the next weeks...

    The TLC6C598 is supplied with 5V. So the VCC voltage is not a problem with the TPIC6C595.

    But the MC is working with 3.3V. The input pins of the TPIC6C595 have a high level of 3.3V instead of 5V.

    Have you any data about the variation of the save high level for the inputs?

  • 0 in reply to user4366237
    TI__Expert 5380 points
    So you have TPIC6C595 on hand and want to use replace TLC6C598 with TPIC6C595? To be frankly, i don't recommend to do so, as the MCU voltage is 3.3V and can't meet TPIC6C595 logic level requirement. We should avoid this risk.

    I would recommend to continue use TLC6C598 in this project. You can reach out the disty or our sales for the support.
  • 0 in reply to Anda Zhang
    Prodigy 120 points
    We've tried to get the TLC6C598 from different distry and broker. We have also contact with your sales support... No TLC6C598 available.

    We have to replace the TLC6C598 with the TPIC6C595.
    We can do a new layout with a level shifter, but it takes time.

    Another idea is to set the 5V to 4.5V and the 3.3V to 3.6V. But we violate the logic level requirement. But we need not the full temp range, voltage range etc. If you have more data to the logic level requirement it would be very helpfully.
  • 0 in reply to user4366237
    TI__Expert 5380 points

    I understood your situation. But from engineering point of view, i don't recommend to take this risk to use TPIC6C595, as even you have tested several samples, they all worked well, but from mass production side, it is not guaranteed.

    I suggest you search for more suppliers to get TLC6C598/TLC6C598-Q1 device. Now this two device lead time is a little bit long, but we have new device TLC6C5816-Q1 which is made in an advanced  factory, the lead time is shorter.

  • 0 in reply to Anda Zhang
    Prodigy 120 points

    Thank you for your help.

    We'll do a redesign of the LP with level shifts and will use the TPIC.

    Best regards,

    Kilian Hüttenhofer