LMK03318: Use two vcxo to this PLL chip ?

liang ren

Part Number: LMK03318

I would like to use two vcxo to supply for this chip , and using software to select one at one time , is there any problem ?

By the way , in order to minimux the expensive , the two vcxo may be cheap price, so the jitter of the vcxo maybe not good , such as 100 ps rms . So if I make a narrow PLL band by using LMK03318, can I get the output clock jitter below 1ps or 100fs ? (the input and output frequency is 24M and 6M , actruely a divider)

Thanks

over 7 years ago

0 Alan O over 7 years ago

TI__Mastermind 32575 points

This device does not support external VCXO, as the both PLLs have integrated VCO which is the only option. The internal VCO could achieve < 1ps rms jitter (12k-20MHz integration bandwidth) with narrow loop bandwidth, but not 100 fs. The 100 fs spec assumes a low-jitter reference, such as XTAL input with the built-in XTAL oscillator input stage or low-noise XO source with less than 100 fs jitter.

Alan

Clock & timing

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LMK03318: Use two vcxo to this PLL chip ?