LMK1D2102: LMK1D2102R - 50 Ohm Sine wave input support

Esakki Durai

Part Number: LMK1D2102

Tool/software:

Dear Team,

We are searching for the Fanout Buffer (10 MHz) which accepts the Single Ended 50 Ohm Sine Wave Input OCXO and covert it to square wave LVDS reference clock.

We are planning to use the LVDS buffer LMK1D2102R for this purpose.

1) Please clarify that, LMK1D2102R can be used for receiving Single Ended 50 Ohm Sine Wave Input ?

2) If fanout buffer supports this Single Ended 50 Ohm Sine Wave input then what is the recommended input clock termination?

Regards,

Esakki.

1 month ago

0 William Pfennigwerth 1 month ago

TI__Expert 7561 points

Hello,

Sorry for the delay.

1) The LMK1D2102 can accept a 50 ohm sine wave input, although as slew rate decreases, performance will also suffer. With a 10MHz sine wave you will see a noise floor of around -150 dBc/Hz with a RMS jitter from 12kHz-5MHz of > 1.5 picoseconds. So if this level of performance degradation is acceptable, then this could still be an option.

2) Figure 9-6 in the datasheet shows how to input a single ended signal into the LMK1D2102.

Regards,

Will

0 Esakki Durai 20 days ago in reply to William Pfennigwerth

Prodigy 70 points

Dear Will,

Thanks for your reply.

Regards,

esakki

0 Esakki Durai 20 days ago in reply to Esakki Durai

Prodigy 70 points

Dear Will,

Thanks for your reply. Is there any other methods to improve the RMS jitter value.

Regards,

esakki

0 William Pfennigwerth 17 days ago in reply to Esakki Durai

TI__Expert 7561 points

Esakki,

Other than increasing the input power level and therefore the swing, the only other method would be converting the sine wave to a square wave with a LMK1C1102 before inputting this into the LMK1D, this can improve performance.

Do you need LVDS outputs?

Currently, our buffer portfolio is not well suited for low frequency sine wave inputs and differential outputs.

Regards,

Will

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LMK1D2102: LMK1D2102R - 50 Ohm Sine wave input support