LMX2492EVM: Synchronization of RF signal in two boards by trigger input

Amit kumar

Part Number: LMX2492EVM
Other Parts Discussed in Thread: LMX2492

Dear Texas team,

We want to synchronize two signal generators RF output. The signal is a LFM (chirp) signal. Can we use trigger input to synchronize both signal generators.

11 months ago

0 Evan Su 11 months ago

TI__Genius 9750 points

Hi Amit,

Our RF expert is out of the office today but will support you later this week.

Best,

Evan Su

0 Noel Fung 11 months ago in reply to Evan Su

TI__Guru* 81750 points

Hi Amit,

I assume you are saying frequency synchronization of two LMX2492.

We've never evaluated this application, you can try, with the following pre-conditions

1. both LMX devices should share the same reference clock

2. fpd = fosc. That is, R-divider = 1.

3. use a trigger signal to kick start frequency ramping.

0 Amit kumar 11 months ago in reply to Noel Fung

Prodigy 70 points

Can you tell us more how we can perform 3rd option. How can we use trigger signal to kick start frequency? Can you give us any procedure? And is there any delay in starting frequency ramping at RF end.

0 Noel Fung 11 months ago in reply to Amit kumar

TI__Guru* 81750 points

Hi Amit,

You can setup RAMPx_NEXT_TRIG to use an external trigger source to kick start a ramp.

As far as I can remember, once the PLL receives the trigger signal, that particular ramp will get started immediately. However, I did not measure the actual delay time.

0 Amit kumar 11 months ago in reply to Noel Fung

Prodigy 70 points

Can you provide us this actual delay time later? or can you give us any number like maximum delay in microsecond and nano second?

0 Noel Fung 11 months ago in reply to Amit kumar

TI__Guru* 81750 points

Hi Amit,

I would expect it is in nanosecond range.

Clock & timing

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LMX2492EVM: Synchronization of RF signal in two boards by trigger input