LMK04806: LMK04806 Noise Floor

Phat Le

Part Number: LMK04806
Other Parts Discussed in Thread: CODELOADER

Hello,

Please explain why my VCO unit tested on LMK04806 Eval board has very high noise floor.

My VCO @ 1MHz offset around -165dBc/Hz but when I program using the LMK04806 , the noise floor raise up to -145dBc/Hz. This was a limit of the chip or something else?

Please advise,

Regards,

Phat

over 6 years ago

0 Phat Le over 6 years ago

Prodigy 110 points

Here is the plot attached

0 Timothy T over 6 years ago in reply to Phat Le

TI__Mastermind 28530 points

Hello,

Can you advise me more about your configuration? Could you share a codeloader .mac file or TICS Pro .tcs file? Or raw hex values?

Sounds like you are using an external VCO?
What is the input power to LMK04806?
Can you share the schematic of your input to Fin?

73,
Timothy

0 Phat Le over 6 years ago in reply to Phat Le

Prodigy 110 points

Hi Tim,

Yes, I used an external VCO 2457.6MHz and external PLL2 loop filter as well. I use 3kHz loop BW intent to lower noise floor but it doesn't seem success.

Input power to LMK04806: 5VDC >300mA

Regards,

PL

0 Phat Le over 6 years ago in reply to Phat Le

Prodigy 110 points

LMK04806_DualPLL_ExtVCO&LPF_PM70.zip

0 Phat Le over 6 years ago in reply to Phat Le

Prodigy 110 points

5706.2457.6MHz_BlockDiagram.pptx

Clock & timing

Clock & timing forum

LMK04806: LMK04806 Noise Floor