HMC802 connection errors

Hi All,

One of my customer made his prototype board with HMC802 mounted.

Three HMC802s are located at output terminal of his prototype and are connected in series.

He made 4 boards of prototype and 2 boards has problem.

The problem is very low impedance between Vdd and GND of HMC802 device with around 2ohm to 10 ohms impedance.

The 2 prototype boards now failed was working okay when he first tested.

Some day later, 2 boards has the trouble as mentioned above.

The symptoms are all the same, very low impedance between Vdd and GND.

He once made test with VSWR meter connected to the output terminal of his board. During his VSWR test, power of his prototype boards was not turned on.

RF power from VSWR meter was around 0dBm.

Could you suggest us what might cause the failure?

If you have any advice to allocate the cause of the problem, please let us know.

In his board, Vdd is +5V, V1 is 0V or 3.3V from FPGA.

He will use HMC802A for his production unit when the problem is resolved.

  Best Regards,