This question is somewhat of a follow-up to this one: https://ez.analog.com/rf/f/q-a/74118/hmc870lc5-hmc871lc5-vgg-and-vc-tl-supply-currents
We have designed the HMC871 into our board and as the first step in the biasing sequence we are trying to apply -2V to VGG. We have a circuit to generate the bias voltage for VGG with a 100 Ohm series resistor to the VGG pin. When our circuit is disconnected from the HMC871 VGG pin it produces -2.0V. However, what we're seeing is that we have trouble reaching the -2V at the VGG pin when the 100 Ohm resistor is there because the VGG pin is sinking almost 9mA of current.
The verified answer to the question referred to above indicates that 5mA should be the absolute maximum current, yet we're seeing almost 9mA. So the VGG pin is only about -1.1V. Does the 9mA current indicate that the HMC871 is broken and needs to be replaced, or could something else be amiss?
One other point, if we proceed, expecting that the -1.1V on VGG will sufficiently pinch off the drain current and then apply the 8.0V to VDD, the current jumps to ~130mA and VC jumps to about +0.7V without us applying any voltage to it.
Thanks in advance for your guidance,
Chris
