Unknown Surface Mount Device

[CapnCavey]

:mrgreen: I have a small circular surface mount device with four pins connected to the four sides, north, south, east and west, as seen in the picture below. The device appears to be a FET and the only markings I see are E5 written on the top. It is part of an amplifier circuit but I don't think it is a transistor, since the board location is listed with a U instead of a Q. I've been trying for days to find the part number, with no success. I know it's not alot of information to go on, but if anyone can help me, it would be most appreciated.

 

[Exo]

You might give the SMD codebook a try
**broken link removed**

but every manufacturer pick's his own markings, so there could be dozens of E5 devices out there, all diffirent...

The only way to be sure is to get a scematic or at least know the manufacturer or its like looking for a needle in a haystack

 

[CapnCavey]

I've tried several codebooks allready. Unfortunately, I don't have any schematics and won't be able to get any. The part is used in the final amplification stage of an RF card belonging to a Terayon Teralink 1000 Proprietary Modem Controller. When the part fails, I still get an output, albeit a at a much lower level than I need.

 

[Sebi]

Maybe this is a GHz frequency IC, like MAR serie.

 

[udi_hakim]

Yes it might be a microwave amplifier like the HP MSA series...

 

[CapnCavey]

Thanks I'm looking into the MSA series. Who makes the MAR series?

 

[CapnCavey]

Thanks guys, I've found the MAR series, it's made by Mini-Circuits. I'm ordering a few samples of the MSA, MAR and the ERA series, also by Mini-Circuits, and see which one matches my part the closest.