I am using the PLL ADF4355 to generate a frequency between 2.2 to 2.3 GHz. While the frequency locks successfully on the evaluation board, it fails to lock on our custom-designed board, even though we have followed the same schematic as provided in the evaluation board documentation. I'm using an STM32 controller with both the evaluation and custom boards.
What could be the possible reasons for the frequency not locking on the custom board? Please suggest potential causes and troubleshooting steps.
In the ADF4355 evaluation board they used the voltage regulator ADM7150ACPZ-5.0, which should output 5V as per its datasheet. However, I am measuring an output of only 3.3V on the evaluation board.
Additionally, I noticed that the ADM7150ACPZ-3.3 version of the IC has a maximum input voltage rating of 5.5V according to the datasheet. But in the evaluation board design, they are supplying 6V to it. How is it working beyond its maximum rated input voltage?
Could you please clarify these observations?
