LMX2594: Issue about output spurs

eva chen

Part Number: LMX2594
Other Parts Discussed in Thread: LMK61PD0A2

Hi,
I have problem about the output measurement results.
Configure the LMX2594 output 10GHz frequency, the spectrum has another spurs (Fig.1). Spurs occur at 13.1MHz intervals, even if I switch to another frequency, this situation still exists(Fig.2).

The reference signal 100MHz, phase detector frequency 200MHz, TICS Pro settings as Fig.3.

Has any ever experienced this similar issues? Is there any way to improve this situation?

Fig.1 _ span 100MHz
Fig.2 _ span 100MHz

Fig.3 Tics Pro setting

This problem has been bothering me for a while, hope someone can give some advice.

Thanks,

Eva.

over 3 years ago

0 Noel Fung over 3 years ago

TI__Guru** 108330 points

Hi Eva,

You are operating it in an integer channel, the 13.1MHz spurs must be some kind of interference from the environment or from the reference clock.

0 eva chen over 3 years ago in reply to Noel Fung

Prodigy 10 points

Hi Noel,

Thanks for your reply.
As your suggestion says,I try to change the reference clock.I used the oscillator "AK5DAF1-100" to provide my reference frequency(100MHz), and then replaced the original with "LMK61PD0A2" and signal generator for testing.

These interference still exist, liked Fig.2 and Fig.3 shows. Are there other possible reasons for this,or any moving I can try?
Fig.2 with LMK61PD0A2, span 100MHz
Fig.3 with Signal generator, span 100MHz