Category: Hardware
Product Number: LTC4267-3
Hello,
I just received some new custom PCBs with PoE controller LTC4267-3.
I already used the same circuit on another PCB before, only with small modifications, mainly now with another Rclass resistor = 45R3 for class 3.
At first the LTC "registered" with the PSE, but after about 500 ms power was turned off.
The problem: the LTC does NOT start switching.
I added a 10k resistor load (Vportp and PGND), now the PSE keeps the input power up, but still no switching action.
The voltage level at ITH/RUN pin is about 0.55V.
I have changed the FET (controlled by nPWRGOOD, also checked that) at ITH/RUN, several resistor values, no success, no switching!
Any ideas?
