TPS2372: can I use a TI DCDC buck converter IC together with POE PD interface chip like TPS2372?

Hello, 

TI PoE PD portfolio has two types of ICs: Standalone PD's and PD's with an integrated PWM controller. 

The complex circuitry is the DCDC converter, with the DCDC (PWM) controller integrated into our IC. Most PoE applications require isolation because of the nature of the application. For example, the phone on most corporate desks require isolation to keep the user safe. This requirement is not driven by PoE, but by the application. So you can use a buck if desired. 

For basic understanding of a flyback, the more simple DCDC isolated topology, please review the following video. 

https://training.ti.com/understanding-basics-flyback-converter#:~:text=A%20flyback%20converter%20is%20a,time%20of%20the%20primary%20switch.

For a deep dive into flyback design, please see the following paper: 

https://www.ti.com/seclit/ml/slup261/slup261.pdf 

The TPS2372 is one of TI's stand alone PD's. This means there is no PWM controller inside of it. You can connect any DCDC you want to the TPS2372. 

However, the TPS2372 is one of our high power devices. For a 15W design stand alone PD, I would recommend the TPS2378 at this time. 

We understand that DCDC design is no simple task, and that is why we provide a large Reference Design Library. These designs have test reports and design files that can streamline your DCDC design process. 

Below is a link of our power management reference design library, filtered to PoE input range with 5V/15W: 

https://www.ti.com/power-management/reference-designs.html?DCMP=pmp-reference-designs&HQS=powerlab#search?DCMP=pmp-reference-designs&HQS=powerlab&famid=64&vinmin=10,42&vinmax=48,60&outpow=0,15&vout=5,5 

From there,  the closest is the PMP110652. You can also see PMP11012

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards, 

Michael P.

Applications Engineer

Texas Instruments 

IEEE802.3.af and IEEE802.3.at are on two twisted pairsets. IEEE802.3.bt is all 4 twisted pairsets. 

Either way, the power and data are separated by a transformer or Ethernet PHY. 

The voltage is considered 0-48V. 

Please see the TI PoE Training Series: 

https://training.ti.com/power-over-ethernet-poe-training-series 

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards, 

Michael P.

Applications Engineer

Texas Instruments 

Hello, 

Using a PD + PWM does make the solution size smaller and removes the PWM controller choice. 

The TPS23757EVM is a 5V/2.2A output (11W). 

If you are looking at this power range, I would suggest the TPS23758EVm-080. This is the newest generation of IC's for this power range, and has the most integrated features -- SSFD, PSR, and integrated primary FET. 

Alternatively the TPS23753A has many reference designs at this power level. 

I can provide Altium files through private messenger. 

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards, 

Michael P.

Applications Engineer

Texas Instruments 

Hello, 

If you look at our PoE PD IC's, they are listed in order of release date, and have a number of parameters to compare: 

https://www.ti.com/power-management/power-over-ethernet-poe/powered-devices/products.html 

There is also the TI Reference design library that I provided link for, which searches through all power reference designs. Hopefully that helps. 

I cannot assist in acquiring samples. My advice is to contact your local TI sales office to get a sale representative working with you. 

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards, 

Michael P.

Applications Engineer

Texas Instruments