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RX ADC output rms voltage in different RX gain

Question asked by little_fish@rf on Jul 5, 2018

Dear SIR,

            the ADC full-scale output voltage Vpk is 1.625V, it equal to 2048 code.

            when i using MGC, and select rx gain index 66, it is 63dB rx gain, NF is about 5dB, when i terminated rx input 50 ohm, configure RX BW to 10MHz, the ADC noise output power can be caculate below:

            Pout = -174dBm/Hz + 10*log(BW) + rx gain + NF

            so the ADC noise output power will be -36dBm, 2.51e-7W, and the noise rms voltage is  3.54mV; the ADC code of 3.54mV is 4 or 5;

            is it correct? i should see the ADC noise output I+JQ rms voltage code to be 4~5 in the matlab FFT?

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