Part Number: SN74LS86A
We are using the SN74lS86ADR IC XOR logic gate in junction with a 74HC08D AND gate. We are using them to blow a fuse. When our laser is fired, it will either hit or miss a phototransistor. If the phototransistor is hit (saturated), then the fuse have wired on our PCB must not blow. If it misses then it should blow. We were applying a 5V input to the IC's Vcc input according to the datasheet. The Arduino we are using to rotate some gears outputs a voltage of 4.6V so we wanted to test the IC with that voltage. According to the Electrical Engineers here at our University the IC should not break but just stop working at that low voltage since it is outside of its voltage range. When we tested it, the fuse blew even when the laser hit the phototransistor, we believe this is because it is lower than the minimum voltage. However, when we went back to a 5V input to the Vcc pin the logic circuit still would not work. We have tried this on two different PCB's. To reiterate, the circuit worked perfectly fine when a 5V supply was given to the Vcc pin. When lowering that voltage the circuit stopped working even when the voltage was restored to the 5V.
