Hello, I am using a ULN2803 load driver to activate/deactivate a 3.3V sensor. I am doing this by connecting the sensors ground to the output of the ULN2803. When sending 3.3V to the ULN2803 input, the ULN2803 should switch the sensors ground to ground.
Here is a schematic:
When I do this, I am reading 0.6 volt difference between the sensors ground, and the PCB's ground. Similarly, the sensor is outputting a higher analog voltage than normal. I can take an alligator clip and short the sensors ground to PCB's ground and everything is normal.... so for some reason the ULN2803 is not bringing it all the way down to ground?
I read through the datasheet again and it seems this should be working, so I am not sure what is going on? Any help or advice would be greatly appreciated, thanks!
Here is a schematic:
When I do this, I am reading 0.6 volt difference between the sensors ground, and the PCB's ground. Similarly, the sensor is outputting a higher analog voltage than normal. I can take an alligator clip and short the sensors ground to PCB's ground and everything is normal.... so for some reason the ULN2803 is not bringing it all the way down to ground?
I read through the datasheet again and it seems this should be working, so I am not sure what is going on? Any help or advice would be greatly appreciated, thanks!