I've brought 25 three input NOR gate ICs (74HCT27), and it doesn't function the way it's supposed to. It behaves more like a NAND gate, anything to high switches it off.
My allowable supply voltage is 4.5 to 5.5, and mine (through a voltage divider) is approx. 4.6 .
For example, if I leave the out put wires out ( L L L) the LED doesn't turn on. It should though since it's a nor gate.
When I insert a wire and just lightly touch it (on the insulation), the capacitance just on the surface of the insulation turns it on then it fades back off.
I have a feeling however, it might have to do with my input voltage. Which is the same as supply.
Data Sheet:
http://www.nxp.com/documents/data_sheet/74HC_HCT27.pdf
I'll post the test diagram later.
My allowable supply voltage is 4.5 to 5.5, and mine (through a voltage divider) is approx. 4.6 .
For example, if I leave the out put wires out ( L L L) the LED doesn't turn on. It should though since it's a nor gate.
When I insert a wire and just lightly touch it (on the insulation), the capacitance just on the surface of the insulation turns it on then it fades back off.
I have a feeling however, it might have to do with my input voltage. Which is the same as supply.
Data Sheet:
http://www.nxp.com/documents/data_sheet/74HC_HCT27.pdf
I'll post the test diagram later.
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