We have a board with ADM2582EBRWZ used for RS485 communication with 120Ohm termination resistor.The supply voltage is 3.3V.
This board is showing some radiation problems around 660MHz & 990MHz.
We are not sure whether it is because the on chip isolated dc/dc converter that works at 180MHz.
For testing ,
1.Is it possible to shutdown the onchip dc/dc converter by some means..Will DE pin when pulled low will shutdown the power supply?
2.Is the 180MHz oscillator frequency is fixed, and only duty cycle is being changed as per the load current .. or any kind of variation in this 180MHz is implemented.?\
3.Is it possible to power the Visoin from an external isolated 3.3V supply and test circuit is there any kind of problem associated with that?