passive infrared sensor output voltage

[JohnKElectroTech]

Hi. I have a Murata IRA-E710ST0 PIR sensor, where I've tried to attach the sensor circuit diagram and a human detection diagram. If it didn't work, here's the link:

**broken link removed**

I apply constant 5V to the drain and attach the gate to ground. When I cover the sensor so that it won't produce a signal, I get a constant voltage of about 1V from the source terminal. Is this expected? I thought that with no voltage applied to the gate, the output would be zero.

If the output voltage should be about 1V with no motion, do I need to somehow set the voltage to zero before connecting it to an op amp?

Thanks in advance for your help.

 

[Externet]

The leftmost 100KΩ in the circuit is probably the one pulling low that will bring the source voltage from your measured 1V to zero when inactive.