I am trying to build mean square circuit using multiplier AD834. I am using circuit diagram provided in Analog devices application note AN-212. In fig.3 on page 6-41 of this application note there is simple DC to 500MHz Mean Square circuit. When I input 500mvp-p 300KHz I get -210mV across pin 5 and pin 4. When I input 0 volts I get -230mV across pin 5 and pin 4 of AD834. I was expecting 0 volts at these pins. Can anybody help me to find out the reason why the out put is not zero for 0 V input. Also herewith I have attached the table which shows input sine wave value and output DC measured across pin 5 and 4 of AD834. The table shows that the results are not correct. Request you to help me to find out the reason why the circuit is not working as per expectations.
|ADC834 INPUT 300KHz sine wave||DC Voltage measured across pin 5 and 4 of AD834|