I'm not sure how to interpret the RF Input Sensitivity for the ADF4002 (I'm not a RF designer).

According to the datasheet the RF Input Sensitivity is -10 - 0dBm (referred to 50ohm).

We have a differential AC coupled driver (square wave) with 100ohm termination connected to ADF4002 RFinA and RFinB.

What is the maximum allowed voltage swing between RFinA and RFinB to fulfill the specification.

Is it sqrt(1m*10^(0dBm/10)*50) = sqrt(1mW*50ohm) = 224mV?

What happends if the 0dBm specification is violated?

• Hello

The RF inputs can tolerate inputs up to +4dbm ( either single ended or differentially ), exceeding +4dbm can affect functional operation of the device, to convert +4dbm to voltage terms , this is equivalent to 354mV rms, and 1.002 volts pp. If you are using the RF  inputs differentially, this will mean that you should limit the swing on each input to +/-250mVolts ( 180 degrees phase difference between inputs) , resulting in a 1Volt pp across both inputs

Regards,

Brigid.

note: if you google dbm to volts , you will find very usefull conversion tables.

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Thank you,