Part Number:AM1705
Hello Champs,
Customer would like a schematic review for the AM1705. He made two different designs (with different connections) and both have suffered the same problem of the PLL not initializing correctly. The process correctly executes all code that has been flashed to it as long as it does not enable the PLL.
In the first revision of the design, he had 120ohm ferrite beads on the power supplies with a single 0.1uF. In the second revision he got 60ohm ferrites with a 10uF, 1uF, 0.1uF and 1000pF capacitors. Would the missing 0.01uF capacitor cause this much disruption?
He can't initialize the PLL in emulation mode. He can get access to the registers but when enabling the PLL, he lose control of the processor.
All of the power supplies are good and the reset pin has a 10k pull up to 3.3V.
I advise him to change the ferrite beads. Customer changed the capacitors and ferrites, but he is still observing the same thing.
Any advice will be greatly appreciated.
Best Regards
Shine