Post Go back to editing

# HMC1082 Maximum Ratings

Reading the HMC1082 datasheet I could not find the maximum ratings for the gate voltage, only the suggested range from -2V to zero in which the Idd can reach 220mA.

I'm following this procedure to turn on the amplifier with the minimum noise produced on the output:

- Set the gate voltage to a high negative level

- Set the drain voltage to the operating tension

- Raise Vg to the operating level

Is this procedure correct or needed at all? If so, for the first step I need to know what the correct level is, -2V or higher?

Thank you all in advance for any feedback,

Luca

Parents
• Hi Luca,

Max for Vgate is 0 V and min is -2 V. Recommended power up sequence is,

Connect GND.

Set Vggs to -2 V.

Set Vdds to 5 V. Idq is about 0 mA at this point.

Increase Vgg towards 0 V stop when Idq=220 mA.

Apply RF.

Follow reverse order for power down.

And the Application Note AN-1363.

Best,

Kagan

• Hi Kagan,

I'm confused about the HMC1082 datasheet:

The datasheet of the HMC1082 is unspecific whether the set current Idd is meant as quiescent current or as operating current. Without further information and without knowing about the active bias controller HMC980 (which is not mentioned in the HMC1082 datasheet) I would assume the typical Idd given for the HMC1082 is meant as quiescent current, specifically given the fact that figure "Power Compression @ 12 GHz", page 4, shows the expected increase in supply current.

The application note AN-1363 for the active bias controller HMC980LP4E however suggests, that Idd of the HMC1082 is meant to be kept constant throughout different operating conditions.

--> The typical performance shown in the datasheet of the HMC1082, is this measured with constant Vgg or with constant Idd? (in particular plots "P1dB vs. Supply Current" or "Psat vs. Supply Current")

--> Can I simply adjust Vgg such that Idd (quiescent at Vdd 5V) is e.g. 200mA and operate the amplifier up to the max. output power without risking to damage the amplifier?

Thank you and Kind Regards

Mathias

• Hi Kagan,

I'm confused about the HMC1082 datasheet:

The datasheet of the HMC1082 is unspecific whether the set current Idd is meant as quiescent current or as operating current. Without further information and without knowing about the active bias controller HMC980 (which is not mentioned in the HMC1082 datasheet) I would assume the typical Idd given for the HMC1082 is meant as quiescent current, specifically given the fact that figure "Power Compression @ 12 GHz", page 4, shows the expected increase in supply current.

The application note AN-1363 for the active bias controller HMC980LP4E however suggests, that Idd of the HMC1082 is meant to be kept constant throughout different operating conditions.

--> The typical performance shown in the datasheet of the HMC1082, is this measured with constant Vgg or with constant Idd? (in particular plots "P1dB vs. Supply Current" or "Psat vs. Supply Current")

--> Can I simply adjust Vgg such that Idd (quiescent at Vdd 5V) is e.g. 200mA and operate the amplifier up to the max. output power without risking to damage the amplifier?

Thank you and Kind Regards

Mathias

Children
• The above "ADIApproved" answer suggests that Idd is meant as quiescent current:

Set Vggs to -2 V.

Set Vdds to 5 V. Idq is about 0 mA at this point.

Increase Vgg towards 0 V stop when Idq=220 mA.

Apply RF.

Can someone from ADI comment on this?

Thank you and Kind Regards

Mathias