On the TPS23756 datasheet section 7.3.8 Frequency and Synchronization (FRS), we note that the typical resistor (Rfrs) on the high impedance input FRS pin is say 68.1k Ohms (or whatever it is)
I wanted to use the Frequency Dithering noted in section " 8.2.2.19 Frequency Dithering for Conducted Emissions Control " but noticed when I connect only the Dithering circuit, but NOT the original Rfrs, the POE converter no longer works (turns on to about 40% voltage output, then trickles down to about 20% and more or less stops).
Is Rfrs intended to be used in "parallel" with the Frequency Dithering output? Or should the Frequency Dithering output replace Rfrs?
If the Frequency Dithering output should replace Rfrs I am guessing I did something wrong in the opamp setup and will get to a scope in a day or two.
Less important to answer since I'm feeling like I'm running out of question points... but still curious...
Can I assume the frequency dithering circuit is just an opamp oscillator? There's a few more parts on the 8.2.2.19 circuit that I'm not as used to seeing and clearly I am far far from an analog guru. :)
What's the role of the 49.9k resistor? (just slow down charging of the RC circuit for negative feedback at power on? a pullup?)
Looks like the 301k resistor+ 0.1uf cap to the output is like a filter?
