LMX2594: Does TI have lower BW solution like LX2594?

Jimmy WANG

Genius 4165 points

Part Number: LMX2594
Other Parts Discussed in Thread: LMX2572LP, , LMX2572, LMX2571

Hi team,

Does TI have a suitable solution BW lower than LM2954? due to customers do not need 15GHz BW. just need 10~100MHz.

But need important function is 32-bit fractional-N divider.

Is there such a suitable solution? thanks

over 2 years ago

0 Dean Banerjee over 2 years ago

TI__Mastermind 28021 points

Jimmy,

The LMX2572/LMX2572LP is a lower frequency version of the LMX2594. The phase noise is a few dB worse, but the current is significantly lower. It is pinout compatible to the LMX2594 and the programming is very similar and has the same feature set.

We also have the LMX2571 that is even lower current, but not pinout or program compatible to the LMX2594 and not the same feature set.

Regards,
Dean

0 Jimmy WANG over 2 years ago in reply to Dean Banerjee

Genius 4165 points

Hi Dean,

But LMX2572 I can not see about jitter spec. LMX2594 has • 45-fs rms jitter at 7.5 GHz (100 Hz to 100 MHz).

So does LMX2572 have the spec like this? thanks

0 Noel Fung over 2 years ago in reply to Jimmy WANG

TI__Guru** 110790 points

Hi Jimmy,

What is customer's requirement on phase noise or jitter?

0 Jimmy WANG over 2 years ago in reply to Noel Fung

Genius 4165 points

Hi Noel,

Custimer hopes the same with LMX2594. thanks

0 Noel Fung over 2 years ago in reply to Jimmy WANG

TI__Guru** 110790 points

Hi Jimmy,

They are targeted for different market, performance and price are different. If you need the performance of LMX2594, then use LMX2594.

0 Jimmy WANG over 2 years ago in reply to Noel Fung

Genius 4165 points

Hi Noel,

Got it. So does LMX2572 no like this spec? right?

+1 Noel Fung over 2 years ago in reply to Jimmy WANG

TI__Guru** 110790 points

Hi Jimmy,

All synthesizers will specify its VCO phase noise, this is the key specification of a synthesizer. Jitter is another way to represent phase noise. However, jitter will dependent on the loop filter design and the integration bandwidth so usually synthesizer does not specify jitter. Jitter is calculated from phase noise, as long as we know the phase noise, we can calculate jitter based on the integration bandwidth. We can use PLL Sim (www.ti.com/.../PLLATINUMSIM-SW) to design the loop filter and simulate the phase noise and jitter.

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LMX2594: Does TI have lower BW solution like LX2594?