Biasing HMC460LC5

I am having an issue biasing the HMC460LC5.

First, after setting both the gate and drain voltages to 0V, when I decrease the gate voltage towards pinchoff, the gate current increases to 14mA  by the time I get to -2V which is well beyond its rated max 2.5mA.

Second, If I continue and try to set the drain voltage, the drain current increases as I increase the voltage. It goes beyond the 75mA operating bias current well before reaching the 8V bias voltage, around 5V.

I am using the Hittite eval board with 50ohm terminated RF in and out.

Did I damage the part and now it's not functional or am I doing something wrong?

  • HI,

    How did you terminate the RF ports of the EVB? Could you repeat the same biasing with RF in and out ports of the EVB open?

    Note that, as described on the datasheet, RF in and out ports of HMC460LC5 are DC coupled. You need to use DC block caps at those pins. If you terminated the RF inputs without AC coupling, this could be the problem.

    Best,

    Kagan

  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:37 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

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    EZ Admin