Other Parts Discussed in Thread: TRF37B73
Our customer is using the TRF37A75 and TRF37B73 devices in their system and they are testing their prototype. The following concern was raised
I am currently designing a number of RF Amplifiers based on TRF37A75 and TRF37B73. During testing I've found 2 cases one TRF37A75 and one TRF37B73 that showed after some time an increased supply current of 2 to 3 times the normal amount. In both cases the gain and compression was still more or less unchanged and they functioned as normal.
In first case I wasn't sure if I've had the device damaged mechanically (PCB flexing) and I've replaced it. Now a second case has come up. In this case the current started to float up and after a while settled back to normal, again it functioned "normal" and I could not notice any wild oscillation.
However, in both cases I've had relative small input/output coupling caps of 2.7pF for a 4.7 GHz application, otherwise the supply circuit as per application note.
Am I doing something wrong?
Do they need a higher input capacity (1nF) to stabilize the active bias?
Are there any further information available, such as a internal block diagram ?
The point is that I am getting a bit concerned as we've got about 10 of these devices in our new design and I don't want to get caught with production issues.
Thanks very much