HMC980LP4E Power Supply Sequencing

Hi Barath,

Always apply the VDIG supply (Pin 9) first to the HMC980LP4E. Secondly, apply the VDD (Pin 1 and Pin 2) voltage to the HMC980LP4E. If operating the HMC980LP4E with an external negative voltage on VNEG, apply this voltage to VNEG (Pin 15) last.

After all supply voltages are on, the HMC980LP4E can be enabled by asserting EN (Pin 5) to begin biasing the RF amplifier. Note that EN has an internal pull‑up to VDIG.

Thanks,

DanO

Can you please explain why this sequencing is required? What will happen if we deviate this? From where you got these details as it is not mentioned in the datasheet.

Hi Barath,

Please see the literature below.

In summary, it is to ensure the health of the HMC980 and external amplifier it's biasing.

Thanks,

DanO

Thanks for reply. But what is the OFF sequence for this active bias controller. Is it need to turn off in reverse order? Information is not available in datasheet. Please respond.

Hi Barath,

Yes, powering down is the same sequencing in reverse order.

Thanks,

DanO

Hi. Thanks for your reply. Is there any recommended time delay specification for this sequenced power supply. If yes what should be the minimum delay required for sequencing?

Hi Barath,

There is not a specific time delay spec for the sequence.

Although the proper power sequence needs to be followed.

Thanks,

DanO

Hi Barath,

There is not a specific time delay spec for the sequence.

Although the proper power sequence needs to be followed.

Thanks,

DanO