74LS Quad 2-Input AND Gates. General Description. This device contains four independent gates each of which performs the logic AND function. Ordering. 74LS08, 74LS08 Datasheet, 74LS08 Quad 2-input AND Gate, buy 74LS08, ic 74LS Note The ”Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaran- teed The device should not be operated at.
|Published (Last):||19 September 2012|
|PDF File Size:||2.18 Mb|
|ePub File Size:||15.76 Mb|
|Price:||Free* [*Free Regsitration Required]|
In the circuit 74ls08 transistors are connected in series to form a AND gate. You could try adding a pull 74lx08 resistor k, K, ohm, doesn’t much matter your inputs may be floating high. The inputs on CMOS parts anything with a “C” in the middle source or sink very little current, so 74ls08 pull-up or -down will work with 74ls08.
The chip is basically used where AND logic operation 744ls08 needed. The inputs with both switches unpressed allow the pins to float 74ls08, depending on the way the IC is set-up 74ls08.
Then if your IC is good your switches 74ls08 mis-wired, I have done it myself with that type of switch.
For better understanding the 74ls08 working let us consider 74ls08 simplified internal circuit of AND gate 74ls08 shown below. For realizing the above truth table let us take a simple AND gate application circuit as shown below. Both transistors will be ON and voltage across both of them will be zero.
With that the drop across resistor R1 will 74ls08 zero. I 74ls08 tried switching to a 9v battery and nothing changes. The inputs of the 74LS 74ls08 and other TTL versions source significant current and will appear as a logic High unless 74ls08 pulled to Ground – your k resistors won’t help. Because output is nothing but voltage across resistor R1 it will be LOW. With the LS you need to sink 1. When any one of the buttons is pressed. When both 74ls08 are pressed. After verifying the three states, you can tell that we have satisfied the above truth table.
74ls08 5K1 pull-up resistor ensures that the pin is seen as High when the switch is not pressed.
74ls08 are four legs connected together in 74ls08 of two. Post as a guest Name. The four AND gates in the chip mentioned earlier are 74ls08 internally as shown in diagram below. 74ls08 you want to absolutely avoid learning the pin out of these push buttons, 74ls08 connect them in diagonal. 74ls08 up or log in Sign up 74ls08 Google.
74LS08 Quad 2-Input AND Gates IC
The two inputs of AND gate are driven out from bases of the two transistors. Many pins left floating. Because of 74ls08 the chip can be used for high speed AND operations.
Next Article Timer IC. 74ls08 am new to electrical engineering still so forgive me if I 74ls08 making a stupid mistake. And after a google 74ls08 I havnt come up with anything, usually the videos are terrible quality or they are using a different AND gate.
You might be using push buttons that are connected in 74ls08 a way that the legs are shorted connected together. Simon Marcoux 1 If you do use a pull down resistor, make it low like PeterBennett recommended.
This LED is connected to 74ls08 the state of output. Looking at the image I agree. Skip to main content.