Reading datasheets to pick a comparator

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akaliuseheal
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Hello,
I've got a voltage comparator, well only on schematics, I need to chose one and I need some help interpreting datasheet. The datasheet I was looking at is of a lm393. My input voltage ranges from -7.8V to +7.8V. The datasheet says -0.3 to something. So it's not usable, right?
I was also looking at lm111 and here it is stated that input voltage can be from -15V to +15V which is great but I can't find information about output sink current.
 
akaliuseheal said:
The datasheet says -0.3 to something. So it's not usable, right?

You need to spend some time reading datasheets to learn the vocabulary.
The limitation is input voltage should lie between the power supply "rails"

That comparator can handle a dual supply of +&- 15 volts.
so you +&- 7.8 is well within that range.
You just have to give the comparatpr a +&- supply.
Circuit schematic of a comparator with a negative reference: VIN source feeds the non-inverting input, the inverting input is tied to -5 VDC, V+ and V- supply pins, and the output Vo goes through a 5.1k pull-up resistor. Labeled Figure 36 with the part 1/2 LM193.
 
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  • Circuit schematic of a comparator with a negative reference: VIN source feeds the non-inverting input, the inverting input is tied to -5 VDC, V+ and V- supply pins, and the output Vo goes through a 5.1k pull-up resistor. Labeled Figure 36 with the part 1/2 LM193.
    upload_2018-9-15_15-37-5.png
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akaliuseheal said:
I've got a voltage comparator, well only on schematics, I need to chose one and I need some help interpreting datasheet.
Can you Upload the schematic? Use the Upload button in the Edit window to Upload a PDF or JPEG copy. That will help us a lot in suggesting things for you to look for as you pick the comparator IC to us. Thanks. :smile: