TPS23861: Automatic mode

Valery Kravets

Part Number: TPS23861

Tool/software:

The controller is set to recognize the PD per 802.3at.

Is it possible to adjust components (for instance, the 255 mOHMs sensing resistor) so the chip would recognize the PD per 802.3af Class 0 or 3 (15.4W) in auto mode?

3 months ago

0 Diang Xing 3 months ago

TI__Mastermind 37071 points

Hi Valery,

Thanks for reaching out! We will look into your questions and get back to you by this week.

Best regards,

Diang

0 Diang Xing 3 months ago in reply to Diang Xing

TI__Mastermind 37071 points

Hi Valery,

In autonomous mode, TPS23861 will work as a Type-2 PSE. To make it only Type-1, you need to configure the PSE by I2C

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/723204/faq-tps23861-how-to-configure-to-output-type1-power-even-if-a-type-2-pd-is-connected

The major risk of changing sensing resistor is the classification current read by PSE will be increased too, which could cause classification failure. But Class0 could be fine if the PD's classification resistor is open. The PSE inrush current could be reduced too but it should be a minor risk since PD normally has much lower inrush current limit.

Best regards,

Diang

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TPS23861: Automatic mode