LMK00308: Does LMK00308 accept sine-wave input?

haopeng han

Part Number: LMK00308

Hi,

we need a clock buffer/mux which is able to multiplex two input and fan out 8 output . One of the input signals is LVDS(0-1000MHz), the other is analog sine-wave(0-100MHz). The output signal should be LVDS. LMK00308 looks nice, we want to know if it can support sine-wave input or is there any recommendation on how to make it work. Thanks!

Best,

over 7 years ago

0 Alan O over 7 years ago

TI__Mastermind 32575 points

Yes, you can apply a sine-wave input through an AC coupling capacitor to the OSCin input pin (leave OSCout pin floating).

Regards,

Alan

0 haopeng han over 7 years ago in reply to Alan O

Expert 1120 points

Thanks Alan for the confirmation.
A follow up question: What is magnitude requirement for the sine-wave in order to interface OSCin? I only found the Fmax =250M but no info on magnitude.

Best,
HP

0 Alan O over 7 years ago in reply to haopeng han

TI__Mastermind 32575 points

1 to 2 Vpp swing is the suggested range, and higher swing/slew rate is recommended for better performance.

Regards,
Alan

0 haopeng han over 7 years ago in reply to Alan O

Expert 1120 points

Thanks Alan.

In thread e2e.ti.com/.../697448 you suggested to connect the sine-wave to CLKin instead of OSCin. Which is better in terms of performance?

0 Alan O over 7 years ago in reply to haopeng han

TI__Mastermind 32575 points

For a sine-wave with input, OSCin performs better than CLKin up to about 150 MHz In terms of additive phase noise/jitter.

If the single-ended input slew rate is faster than 2 V/ns, then CLKin will perform better than OSCin.

Regards,
Alan

0 haopeng han over 7 years ago in reply to Alan O

Expert 1120 points

Thanks！

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LMK00308: Does LMK00308 accept sine-wave input?