This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS23881: SRAM programming

Part Number: TPS23881
Other Parts Discussed in Thread: TPS23882B, TPS23882, TIDA-050026-23881

Hello there:

I am seeing different PSE topologies and some of them require a separate MCU to control and this one TPS23881 has the embedded one. As of fw development/control prospective, which solution would be easier? And for this PSE controller and if I want it to be working together with some SoC do we only need I2C support?  

  • Hi Ryan,

    Thank you for your question.

    Can you tell me a little about what the application or technology this PSE will be used for? There are many PSE solutions and each of them work well for certain design applications. 

    Best Regards,

    Nate Inkster

  • The PSE will have two ports and will be used for powering up two PoE bt level devices, such as cameras. We should be able to control the max power allowed for each of the ports and some default protection features provided from this PSE controller. 

  • Ryan,

    I see, thank you for providing that info. Do you know what the power requirements are and whether or not these ports will need to be 2-pair or 4-pair? If the solution you need utilizes 4-pair ports and and requires above 30W, then we recommend the TPS23881 with MCU, but if you just need 2-pair ports, the TPS23882 with MCU or TPS23882B with autonomous mode may suit your needs.  

    Best Regards,

    Nate

  • Hello Nate:

    Thanks for your response. Yes it is gonna be a 4 pair 90W solution. So based on your response an extra MCU is needed? How is that one differed from the MCU embedded in the chip? 

  • Hello Ryan,

    The TPS23881 does not have an MCU embedded in it. For this application, are you planning on using an external MCU to configure the PSE device, or are you interested in autonomous mode? 

    Best Regards,

    Nate 

  • Hello Nate:

    This is what I have found on the datasheet and this is where my question is coming from. From my application we want to configure the PSE controller but when I am reading this it seems like we only need the I2C?

    And by looking at the functional diagram this is what I mean by the embedded MCU, so I am thinking what is the main difference between this MCU and the external one.

    Thanks!

  • Hi Ryan,

    I see now, thank you for specifying. The internal MCU serves a different function than the external MCU. When an external MCU is used it serves as the host/master to the PSE. It is possible to use the I2C lines and some other host than an MCU for the internal SRAM programming and to initialize I2C register configuration, but we usually suggest an MCU for ease of use. We also provide a turnkey solution that includes TPS23881, external MCU, and firmware if that is something you would be interested in. 

    Best Regards,
    Nate 

  • Hello Nate:

    Thank you so much for your explanation. Yes, do you have a part number of the turnkey solution that you suggest? 

  • Hi Ryan,

    Yes, it is TIDA-050026-23881 and it is our reference design utilizing TPS23881, MSP430F523x, and FirmPSE solution. The FirmPSE supports power management, multiple power supplies, field upgradability, and more. You can find more details about it here: https://www.ti.com/tool/TIDA-050026-23881

    Please reach out if you have any questions.

    Best Regards,

    Nate 

  • Hello Nate:

    Thanks for sharing the info. I am wondering for the external MCU needed do we have any other solutions rather than MSP430. Do we have any cheaper/less powerful MCU that you suggest using? 

  • Hi Ryan,

    If you would like to use FirmPSE, than MSP430 is the only option, however if you would like to control PSE directly through I2C, than you can use other MCUs. 

    Best Regards,

    Nate 

  • Hello Nate:

    Thanks for your answer. Since our product will have a SoC besides the MSP430, what will be the interface in between the SoC or MSP430, or there is no need? 

    The same question applies to how we are going to upgrade the fw on the MSP430 if needed, can it be done through the our SoC with the interface mentioned above or it has to be manually programmed from the MSP430 directly?

  • Hi Ryan,

    To answer this question I am consulting with our firmware team and awaiting their response. I anticipate a response from them by end of next week and will update you as soon as possible. 

    Best Regards,

    Nate 

  • Thanks Nate. 

    Actually I have another questions while reading the datasheet into more detail. For the current monitoring feature, is the measured value readable through I2C? Or it is a passive monitoring for safety purpose only? 

  • Hi Ryan,

    In response to your earlier question, yes there needs to be an interface between SoC and MSP430. This interface is our FirmPSE Host Interface protocol. 

    For the current sensing question, yes this is a readable value through I2C. Current and voltage for channels 1-4 can be read from the 0x30-0x3C registers. 

    Best Regards,

    Nate