Hello everyone, I am currently developing a PD device, one of the potential options for using it is a 24V Passive POE supplied using an external injector. In the datasheet, in the "AUXILIARY SUPPLY ORing" section, it is indicated that the supply of 24 volts is allowed in the second case, but this applies to the so-called "wall adapters". Is it possible to use Passive PoE adapters, as indicated in the instructions, switching VSS to COM
Hi Nikolay,
Thanks for reaching out to us!
You should be able to short the two points in your drawing circuit to make the passive PoE injector position similar to Option 2. The max duty of TPS23750 is 48.8%, be sure the make the transformer winding turns ratio suitable to make sure your can have a regulated Vout when max duty cycle is not closed.
You could also choose TPS23754/6 PDs which have the PPD pin. PPD pin is for easier design with low voltage passive PoE injector.
Best regards,
Diang
Also, I have a question about the possibility of using the TPS23750PWP to get 7 volts on the output? Would it be enough to simply swap the divider between the SENP and the SEN
Hi Nikolay,
Thanks for your response!
If you want to use a PoE passive injector less than 40-V, you need to short VSS and COM (RTN), which is internally a hotswap.
For the 7-V output, yes you should be able to adjust the voltage divider resistance to get a 7V output. SENP - SEN is about 1.5 V.
Best regards,
Diang
