LMX2541: LMX2541 for output 1G frequency

Mickey Zhang

Genius 12080 points

Part Number: LMX2541

Hi team,

The customer is using LMX2541. The input frequency is 100MHZ. He needs to output 1GHZ frequency.

Would you help me how to set LMX2541 for the customer's application?

Which tool can I recommend the customer?

The customer also needs to know if LMX2541 outputs 1GHZ frequency, when the output frequency is stable?

Best Wishes,
Mickey Zhang
Asia Customer Support Center
Texas Instruments

over 8 years ago

0 Simon Damphousse over 8 years ago

TI__Expert 5370 points

Dear Mickey,

thank you for reaching out. 1 GHz can be generated with many of our devices. Requirement on perfromance or power will often guide your selection. LMX2541 is one choice by using this version:LMX2541SQ2060E and the internal divide by 2. I recommend to use Pllatinum Sim software (available for free on ti.com) to make an assessment of the perfromance and then using TiCS PRO software with our EVM for a complete evaluation.

All our devices feature a lock detect pin to indicate lock.

Regards, Simon.

0 Mickey Zhang over 8 years ago in reply to Simon Damphousse

TI__Genius 12080 points

Hi Simon,

I use Pllatinum Sim and select LMX2541SQ2060E and the internal divide by 2. But the output frequency Fout is 1050MHZ.

When I fill in 1024 to Fout, then some other parameters are changed.

Please check the two cases in the attachment.

Would you provide a correct configuration diagram for output 1GHZ frequency?

Is the a lock detect pin the Ftest/LD 20 pin for LMX2541?

0 Mickey Zhang over 8 years ago in reply to Mickey Zhang

TI__Genius 12080 points

Hi Simon,

Would you continue to support this case? The customer is waiting for my reply.

0 Noel Fung over 8 years ago in reply to Mickey Zhang

TI__Guru** 121130 points

Hi Mickey,
You can put 2000 in the FVCO box to get 1000MHz from Fout box.
C3,C4, R3,R4 are integral components, they are software configurable. If you check the Advanced ratio button in the Featured Level options, you can see the integral components option in the right hand side window.
Right, pin 20 can be configured to be the lock detect output.