LMX2492: Ramp cannot go past 2.1 GHz

Nicholas Strong

Part Number: LMX2492

Good evening,

I can successfully set a single frequency of 2 GHz, 2.25 GHz, 2.5 GHz using the LMX 2492.

We can successfully ramp from 2 GHz to 2.1 GHz, but if we try to set the upper range for the ramp above 2.1 GHz then the ramp either refuses to start or goes haywire.

What could this be caused by?

over 3 years ago

0 Noel Fung over 3 years ago

TI__Guru** 107030 points

Hi Nicholas,

Could you provide your TICS Pro configuration?

0 Nicholas Strong over 3 years ago in reply to Noel Fung

Prodigy 90 points

Sure

0 Nicholas Strong over 3 years ago in reply to Nicholas Strong

Prodigy 90 points

A successful ramp has the end frequency at 2100.

The above configuration will ramp normally for 10 us up to 2100 and then output a very noisy DC signal for 10us and reset. It appears to be losing lock.

0 Noel Fung over 3 years ago in reply to Nicholas Strong

TI__Guru** 107030 points

Hi Nicholas,

Low and High values should be swapped.

Is your VCO Vtune voltage 3V or 5V? Make sure the supply voltage at Vcp matches with your VCO Vtune requirement.

Clock & timing

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LMX2492: Ramp cannot go past 2.1 GHz