lm339 comparator not working

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ibnul7

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Hey guys, I am trying to use a lm339 comparator and for some reason the output never goes high. Is it even supposed to go to full +Vdd? My Vdd is at 9v but my output goes to 0.34 volts when the noninverting input is greater than the inverting.

Thanks
 

Did you observe that its output is open collector type. See the diagram below .

have a collector resistance and connect to Vcc and the output can be measurable at output pin thereafter.
 

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You need to put a pull-up resistor at output.


+++
 

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