LMX2487E:Charge Pump State

Ryota Watanabe

Part Number: LMX2487E
Other Parts Discussed in Thread: LMX2487

Currently we are using TICS Pro v1.7.5.15. to control the registers on the LMX2487. We are able to get it to work correctly.

But I do not know what the CHARGE PUMP STATE represents. (red frame)

What is the difference between active and tri-state?

0 Noel Fung over 2 years ago

Hi Watanabe-san,

Datasheet has below description. Active = normal operation.

0 Ryota Watanabe over 2 years ago in reply to Noel Fung

Dear Noel

Thanks for your advice.

I understand that Active is the normal operation.

When is Tri-state used?

0 Noel Fung over 2 years ago in reply to Ryota Watanabe

Hi Watanabe-san,

it is mainly used for debug purpose. When we make it tri-state, the loop is open, we can measure VCO only phase noise.

0 Ryota Watanabe over 2 years ago in reply to Noel Fung

Dear Noel

I see. I understand now.

Thank you for your explanation.

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