LMX2594: SYNC input usage

Lalit Chaudhari

Prodigy 40 points

Part Number: LMX2594

Hello,

We have several LMX2594 devices on multiple boards. Below is the configuration

Osc_in: 122.88 MHz

RFOutA, RFOutB: 3932.16MHz

In order to get all RFOut* signals phase aligned (from all devices on multiple boards), do I need to use SYNC pin? If yes, can it be a continuous clock running at 7.68MHz? or it must be a single pulse?

over 5 years ago

0 Noel Fung over 5 years ago

TI__Guru** 106720 points

Hi Lalit,

This is a Cat. 1 sync, you don't need a sync signal to trigger the sync. All you should do is enable the VCO_PHASE_SYNC bit; suggest use fpd = 61.44MHz; set MASH_ORDER = 0.

0 Lalit Chaudhari over 5 years ago in reply to Noel Fung

Prodigy 40 points

Thanks Noel.

How does multiple devices's RFOut signals will be phase synchronized without using external SYNC signal? Does OSCin of all devices need to be from same source and length matched? Please clarify.

I will try your suggestions and let you know.

0 Noel Fung over 5 years ago in reply to Lalit Chaudhari

TI__Guru** 106720 points

Hi Lalit,

Yes, all devices should share the same reference clock source in order to maintain phase relationship. See the block diagram in Figure 25 in the datasheet.

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LMX2594: SYNC input usage