HMC788A Power Amplifier Problem

Hi EEMeng,

                   Have you confirmed the part is drawing the correct bias current? 

What frequency range are you operating at?

The lay out is so small and items are not labeled. I'm not sure what I'm looking at. Is it possible to attach the Gerber files?

Regards,

Jim B

Hi Jim

I have attached our gerber and stack up file in word format can you examine and provie us a feedback.

DOCX

Hi EEMeng,

Please confirm the area I highlighted in the attachment is the HMC788A location.

If it is the location, I don't see anything obvious that is wrong with the layout.

Have you confirmed the part is drawing the correct amount of supply current, ~76mA?

Regards,

Jim B

Yes this is the location which we placed the amplifier. We couldn't control the supply current. Because its very hard to measure on pcb and the amplifiers damaged almost instantly when we open a broadcast.

Is the ground paddle of the amplifier soldered to ground? It is not clear from the images you sent.

Please also note that these parts are rated MSL level 3, so damage may occur if the part is not stored correctly before soldering.
Some more info on this at the following link: forum.digikey.com/.../3989

The exposed paddle at the bottom of the package  must be soldered to the ground plane both for electrical grounding and proper thermal transfer of heat out of the device. This is stated in the HMC788A data sheet.

Were MSL3 handling procedures followed?

Regards,

Jim B

Actually its exposed pad connected to the ground plane and its covered by ground polygon. I attached another gerber screenshot which polygons are shelved.

Hi Serhanozyigit,

                                At this point I would suggest contacting your distributor and get some of suspected failing devices returned for FA.

Regards,

Jim B

Hi Serhanozyigit,

                                At this point I would suggest contacting your distributor and get some of suspected failing devices returned for FA.

Regards,

Jim B