I am having trouble with the HMC392LC4. I am unsure as to why I am getting a 20 dB Loss at the output of the cascade of these amplifiers instead of a 30 dB gain. The only difference between the eval circuit and the circuit I used for my PC board is the blocking caps I placed at the inputs and output s of the amplifiers. Could this cause the issue, seeing that the amplifiers have internal DC blocks? Any help will be appreciated.
Thank you all.
Just to add... Upon testing, I am getting a similar broadband response to the one displayed in the datasheet. However, the signal is attenuated rather than amplified.
The biggest issue I think cuasing this problem is that you did not solder your chip to your PC board well ,or the chip groud was not connected to your board ground well.
I'm also using the chip in multiple places on the board and none seem to be working. They all bias up within the range of normal current draw.
ok,I see it .Maybe you should check the RF path,and judge whether the RF signal go through well.
I've attached SMA coax pigtails to the input and output of the amplifier and biased it using an external PSU. The current was 56 mA (55mA is typical), the response was the same. About 10 dB loss at the peak (No gain). What are the chances that all the HMC392 chips were assembled incorrectly (the RF switches that are connected to the amplifiers on the board are also QFN 4X4 with the same footprint and they function as expected) or the chances that all four chips were damaged due to a low ESD tolerance, or even if the 4 IC's were from a bad batch? The only thing we can come up with, similar to you, is a bad RF path, whether internal or external to the chip. Do you have anymore suggestions or tests that we can do? Thank you for your reply.