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TPS23880: TPS23880 questions

Part Number: TPS23880
Other Parts Discussed in Thread: BOOST-PSEMTHR-007,

Dear all:

  TPS23880 have the below questions, please help check, thnak you!

1.If don't singlechip control,Can the power achive 90W in 4 pair mode? if need hardware configure? how to configure?

2.Can auto recognition AF/AT PD in single port BT standard ?

3.If need soft configure when need support 30W and can't exceed 30W in 2 pair mode? if need hardware configure ? how to configure?

  • Xiaowei,

    Please review my initial answers inline along with recommended collateral to study. If having additional questions for follow up, please let us know. I could even put you in contact with local TI FAEs for local training in Mandarin.

    1.If don't singlechip control,Can the power achive 90W in 4 pair mode? if need hardware configure? how to configure?

    A: Yes, the maximum power is 90W at the source. For our recommended hardware design, please review our EVM design located at www.ti.com/.../tps23880evm-008 . We have an EVM User's Guide available (www.ti.com/.../slvub84) which includes the schematic and BOM. Gerber design files are also available.

    2.Can auto recognition AF/AT PD in single port BT standard ?

    A: Yes. The IEEE802.3bt standard is backward compatible, and interoperable with, IEEE802.3af and IEEE802.3at PD controllers. To learn more about the IEEE802.3bt standard itself, please review our .bt standard training portal, located here --> training.ti.com/power-over-ethernet-getting-started-new-standard . This portal has many useful videos and a great white paper co-written by our Design Manager, and IEEE802bt standard comment editor, David Abramson. Direct link to that white paper is ethernetalliance.org/.../WP_EA_Overview8023bt_FINAL.pdf .

    3.If need soft configure when need support 30W and can't exceed 30W in 2 pair mode? if need hardware configure ? how to configure?

    A: I recommend you watch this video to learn more about proper detection and class classification -->  training.ti.com/ieee8023bt-ti-pse-new-features . The video starts to focus on classification around the 7:30 mark. The short answer is that classification is determined by resistor values in the hardware solutions.

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

    On top of Thomas's comments, I need your clarification on the questions.

    1.If don't singlechip control,Can the power achive 90W in 4 pair mode? if need hardware configure? how to configure?

    What do you mean by "don't single chip control"? We have TPS23880EVM-008 and BOOST-PSEMTHR-007 for the hardware design and MSP430 reference code for the software control as a reference. 

    3.If need soft configure when need support 30W and can't exceed 30W in 2 pair mode? if need hardware configure ? how to configure?

    You can configure the power power allocation in register 0x29.

    Thanks.

    Penny