TPS2388: 12-port switch structure

Hello Ken. Before I assign this thread to our PSE Application Engineer for deeper technical answers, I want to help you select the best PSE controller for your customer.

In addition to the TPS23861 and TPS2388, we have the TPS23880. The best way to compare these 3 solutions is by reviewing the PSE parametric search table results here --> www.ti.com/.../products.html . This allows you to easily compare feature sets between the 3 options. The biggest differences are power level and standard supported, port count, and whether or not autonomous mode (the ability to run without ever having to have i2C communication with the PSE) is included. For example, to your first question, the TPS2388 and TPS23880 do not have autonomous mode. However, if the customer wants 8 ports (TPS2388) or IEEE802.3bt readiness (TPS23880) we can work with them to explain auto and semiauto modes (different from autonomous mode) and required setup/system software requirements (as these two solutions do not have autonomous mode).

Let us know once you have discussed this parametric table with your end customer and they have given you more guidance on which PSE is best for them to study more deeply.

Thank you for your local support and promotion of PoE products from Texas Instruments,

Hi Thomas, customer just want to design IEEE802.3 AT, first question i have some error, not in Auto mode, is semiauto mode.
Thank you.

Ken,

Ok I understand that you are looking for an IEEE802.3at compliant PSE. Then, yes, you are correct - TPS23861 and TPS2388 are the best options.

I also understand the preferred operating mode is semiauto. What are the questions/support you still need answered? Depending on the complexity, I might assign this thread to our PSE Applications Engineer.

Thanks,

those question i can't find in datasheet, please help.

2. TPS2388 i never find any document to set the Icut variable, Same TPS23861?? MAX 920mA?

3. TPS23861 datasheet i don't find the some information about 1. I limite 2. Overload

OK Ken. I am assigning this thread to Penny Xu, PSE Application Engineer. She can assist you with these questions.

Thanks,

Hi Penny
TPS2388 Icut setting 0x1E & 0x1F, ICUT = (N × ICSTEP) + ICOFFS, example : i set register 0x1E is 1111 1111'b, so port 1 & port2 Icut= Nx40mA+320mA , N means?