I designed the circuit according to datasheet. The input end is connected with 100nF capacitor in series and 75 Ω resistor in parallel. According to the manual, the input impedance is close to 50 Ω, but the input impedance I actually measured is 75 Ω. Then there is the output problem. I use the mode of time to ground reference. First of all, the zero input will produce an output voltage of 200mV. Does that mean that my output needs to subtract 200mV to be the correct output, but even so, the scale factor is not correct. Is my input impedance not matched?
thanks for your answer