UCC2894: About Electromagnetic noise immunity

Hello,

What do you mean "It has stop when received near 100MHz noise".  Can you give more details? Thanks. 

Hi Sean,

I confirmed detail with customer. They are testing electromagnetics immunity(EMI) with they made board using UCC2894D. The topology is back-boost.
When gradually ramp-up the frequency of electromagnetics wave, it reached near 100MHz, the testing board has stop behavior. If the frequency rises further, the board will reboot.
When the customer added cera-caps(0.1uF) on LINEUV and LINEOV, the board did not to start up.

Could you let me know any advice about this issue?

Best regards,
ACGUY

Is the injected wave radiated or conducted? If is it radiated, is the shield able to help?

Hi Sean,

Is the injected wave radiated or conducted?
->The board has been tested in an anechoic chamber, so waveforms cannot be observed.

If is it radiated, is the shield able to help?
->Due to size and volume restrictions, it is not possible to provide an electromagnetic wave shield. Therefore, I think that there is no choice but to identify the intrusion route of electromagnetic waves and install a capacitor that is effective against 100MHz electromagnetic waves on the board.

If you know of any point or port where this device may stop working due to electromagnetic waves, please let us know.
Also, I would appreciate it if you could explain why the device does not work if you install capacitors on LINE UV and LINE OV.

Best regards,
ACGUY

Hi, ACGUY,

I don't know what exactly happen with 100MHz EM wave injection.  If you reduce the aptitude, does it help? I guess strong electrical field causes internal circuitry misbehavior. If any pins are open, it is better to tied to the ground. SYNC pin may cause internal clock to go wrong if it is left open. 

I think this is a special test, do you have a standard to follow?

Thanks,

Sean

Hi Sean,

Do you know the CISPR? It's a common requiament about safety for electromagnetic in the WW.
In order to obtain the CE mark with CISPR approval, the electrical equipment must be irradiated with electromagnetic waves to prove that the equipment does not malfunction.
Irradiates electromagnetic waves with a wide frequency.

The customer's product stopped due to electromagnetic waves near 100MHz. Some individuals may stop latching. UCC2894 does not have a latch stop function. Therefore, I and my customers believe that UCC2894 is malfunctioning due to electromagnetic waves.
I'm not asking for compensation.
If TI has a solution or idea, please let us know.

Best regards,
ACGUY