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TLV1117: New chip or legacy chip

John11513
Expert 5720 points
Part Number: TLV1117

Tool/software:

Hi team,

I am confused by TLV1117 datasheet. Based on datasheet, this part has two version: legacy chip and new chip. New chip provide two package options: DCY and KVU, legacy chip provide 4 options: KTT, KCT, KCS, and DRJ. (see page 1, datasheet). However, from section '5.4 Thermal Information (Legacy chip)', you can find, the legacy chip has all kinds of 8 package options!

Based on section '8.1.1 Device Nomenclature', the legacy or new chip can be differentiated based on packaging label. My question is, How can customer know the devices they are booking is new or legacy chip? How can a customer designates legacy or new chip when they place order to TI?

In terms of performance, based on datasheet, it seems new chip support ceramic output cap ("5.3 Recommended Operating Conditions" says Cout ESR requirement is 2m ohm to 500m ohm). While my customer reported their TLV1117-33IDCY (based on datasheet page 1 it should be new chip.) output is unstable when working with 10uF/10V X5R ceramic cap, and the device can work stably when changes Cout to 10uF tantalum cap. Is this a legacy chip? How should we differentiate legacy or new chip? what is the requirement for COUT for legacy or new chip? This part is really confused.

Thank you!

John

  • 0
    TI__Expert 5720 points

    Any idea about this question?

    Thanks,

    John

  • 0 in reply to John11513
    TI__Expert 6799 points

    Hey John, 

    Thank you for your patience here! Apologies for the confusion here, there are different package options for both legacy and new chip. The easiest way to tell is to check the label on the package CSO: RFAB or FFAB. To request a specific flow, I would recommend reaching out to your sales representative to help coordinate this. 

    For the Cout capacitor questions I would recommend following the recommended operating conditions for new chip, fixed output. On the front page this refers to the adjustable version of the device. 

    Thank you! 

    McKyla

  • 0 in reply to McKyla Beuttler
    TI__Expert 5720 points

    Hi McKyla,

    Thank you for reply.

    The problem is my customer does use fixed out version (TLV1117-33IDCY) and follow the recommended operating condition (ESR: 2mΩ to 500mΩ), while they met stability problem. The LDO output oscillates with X5R ceramic cap. However the LDO output became stable once then changed output cap to tantalum 10uF cap, which typically has ESR > 1Ω. Completely different from what datasheet says.

    Regards,

    John

  • 0 in reply to John11513
    TI__Expert 5060 points

    Hi John,

    Thanks for the information.

    This behavior seems like the legacy chip:

    (Note that we should consider this information applicable to the fixed legacy version as it appears as an unqualified requirement on datasheet versions which predate the new chip)

      -  What frequency is it oscillating at?

      -  Do you have more information on their output capacitor (Part number, package designation, measured ESR or ESL, etc)? This may help in our support.

    I would expect 200mΩ - 500mΩ ESR to work for both chips, try adding a small resistor in series with the output capacitor to bring ESR into the intersected range.

    Do we know what the label on the package the customer was using said?

    Best,

    Gregory Thompson

  • 0 in reply to Gregory Thompson
    TI__Expert 5720 points

    Hi Gregory,

    Thank you.

    It is clear the device in customer side is legacy chip. 

    What is below description in datasheet means:

    Doers it means in future all new chip will packaged in DCY and KVU and with only fixed version, all legacy chip will packaged in KTT, KCT, KCS, and DRJ, and only provide adjustable version? 

    Regards,

    John

  • +1 in reply to John11513
    TI__Expert 6799 points

    Hey John, 

    Thank you for your question here and apologies on the confusion and unclear information. This will be updated in our next revision of the datasheet thank you again for feedback here. The new chips are available in DCY, KVU, and NDP packages in adjustable and fixed voltage options. These packages (DCY, KVU, and NDP) also have the ability to have either new chip or legacy chip shipped for a period of time to give our customers transition time while moving over to the new chip. 

    For the KTT, KCT, KCS, and DRJ packages these will only be available in the legacy chip options. 

    Thank you, please let me know if there any additional questions! 

    Best regards,

    McKyla

  • 0 in reply to McKyla Beuttler
    TI__Expert 5720 points

    Thank you for clarify

  • 0 in reply to John11513
    TI__Expert 6799 points

    You're welcome! Thank you for your patience here. 

    McKyla