LMX2592EVM

Hi Shaun,

Thank you for your interest in our products. We received your question and will be answering it as soon as possible. We appreciate your patience.

Best Regards,
Julian

Hi Shaun,

1) Yes, it supports input signals from 5MHz to 1400MHz
You Must Switch R14p to R14, which routes the input signal from the OSCinP SMA connector instead of on-board Oscillator.
(c) IMPORTANT NOTE: Phase noise of input signal should be below –150 dBc/Hz at 10-kHz offset for 100-MHz signal, otherwise the input reference noise will dominate the in-band phase noise at RF output. The On-board Oscillator is only at –134 dBc/Hz.
2) Square wave is fine. Clipped sine wave is fine also. The device is triggered on the rising edges of the signal.
3) 0.2V to 2V is the voltage range for REFin. In general, you want low amplitude, fast slew rate, like LVDS.
Voltage can be converted to dBm. Pdbm = 10*log( Vpp^2/8/50ohm / 1 mW)
i. 0.2V is -10 dBm
ii. 2V is +10 dBm

Best Regards,
Julian

Hi Julian,

Thanks for info.
 
1) Can you show me the schematic where R14 & R14p is?

I based on Fig32 on datasheet (which may be different from eval board) & I can only choose between on-board oscillator & OSCinP is R16 & R16p.

2) Also, what about OSCinM port? Do I need to terminate it with 50 ohm?

Thanks.

Hi Shaun,

1) The schematic on the datasheet needs to be updated. For the updated schematic please refer to the LMX2592EVM User's guide. Figure 4-1.

Check the attached image for the location of R14 &R14P.

If you will not use the on board oscillator, you should also remove R15 to remove power from the oscillator.

2) Go ahead and use a 50 ohm termination for the unused OSCin port.

Best Regards,

Julian Di Matteo

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Hi,

1. Can we input Sine wave, 1.5V p-p ±0.5V into 50Ω with +7dBm +/-3dB to OSCinP SMA connector?