Hi
1. Question introduction
Our product have done EMC test And we found that whether connected with PHY module or peripherals or the pure power-on state will approach or exceed the critical EMC value at some frequency points.And only three RS485 and one Gigabit Network ports on board;
2. Specific phenomena
(1) Running test program status: 485 pairs of tests, gigabit network port Ping routing; EMI Test result as below:
(2) Pure power-on state, do not run the test program; 175M is close to the critical point;
So regardless of whether the test program runs or not, 175M and other frequency points are basically critical or exceed the standard.
A. CPU crystal is 24M, which function module may be doubled to 175M?
B. Any other suggestions for rectification?
