LMX2571: inquiry for Lock detection

Harry Ma

Part Number: LMX2571

Hi Team

What is the error between the output frequency and the desired frequency, we think it is locked at this moment, and the Lock detection will switch the level?

Thanks!

over 2 years ago

0 Noel Fung over 2 years ago

TI__Guru** 108270 points

Hi Harry,

When it is locked, the output frequency should be exactly equal to the configuration and lock detect will turn High.

0 Harry Ma over 2 years ago in reply to Noel Fung

TI__Intellectual 2660 points

Hi noel

So there is no any tolerance? Like the error between the output frequency actually and configured frequency is within 3%, the LMX2571 will consider it is under the locked state.

0 Noel Fung over 2 years ago in reply to Harry Ma

TI__Guru** 108270 points

Hi Harry,

The PLL is used to make the VCO track the reference clock, so at any time VCO frequency is proportional to the reference clock. If LMX2571 say lock, I guess it is a measurement issue. You can measure the reference clock frequency to see if there is also a 3% frequency error.

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LMX2571: inquiry for Lock detection