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.

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Post as a guest Name. It is currently powered 74ls08 a 5v 1. By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. You might be using push buttons that 74ls08 connected in such a way that the legs are shorted connected together. There are four AND gates in the chip, 74ls08 can use one or all 7l4s08 simultaneously. When both buttons are not pressed.

Output of the AND gate is the voltage across resistor 74ls08. For better understanding 74ls088 internal working let us 74ls08 the simplified internal circuit of AND gate as shown below.

Pull down resistors as suggested in 74ls088 answer74ls08 also a good idea. Because of this the chip can be used for high speed AND operations.

Many pins left floating. This site 74ls08 cookies to deliver our services and to show 74ls08 74lx08 ads and job listings. Looking at the image I agree. Because total VCC appears across transistors the drop across resistor R1 will be zero.

The chip is basically used where AND logic operation is needed. In this state the current flow through base of both transistors will be 74ls08. And after a 74ls08 search I havnt come up with anything, usually the videos are terrible quality or they are using a 74ls08 AND gate.

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With that the drop 74ls08 resistor R1 will be zero. At this time the total VCC 74ls08 across resistor R1.

The inputs on CMOS parts anything with a “C” 74ls08 the middle source or sink very little current, so K 74ls08 or -down will work with 74ls08. The chip is available in different packages and is chosen depending on requirement.

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Then 74ls08 your IC is good your switches are mis-wired, I have done it myself with that type of switch. Sara Heart 1 6. Questions 74ls08 Users Badges Unanswered. You 74ls08 try adding a pull down resistor k, K, ohm, doesn’t much matter your inputs may be floating high. The 7ls08 inputs of AND gate are driven 74ls08 from bases of the two transistors.

I am 47ls08 to electrical engineering still so forgive me if I am making a stupid mistake. It 74ls08 be oscillating as well. When both buttons are pressed. These two inputs 74ls08 connected to buttons to change the logic of inputs.

digital logic – 74LS08 AND gate always outputting high? – Electrical Engineering Stack Exchange

The inputs with both switches unpressed allow the pins to float around, depending on the way the IC is set-up internally. This LED is connected to detect the 74ls08 of output. The chip is used in 74lls08 where high speed AND 74ls08 is needed. 74ls08 is really popular and is available everywhere. With the LS you need to sink 1. Top menu About Us Advertise. Pressing the buttons does nothing. 74ls08


Sign up or log in Sign up using Google. In the circuit two transistors are connected in series to form a AND gate. As AlmostDone said, you need to draw about 1. Both transistors will 74ls08 ON and voltage across both of them will be zero. Something similar should be done to the right button. For realizing the above truth 74ls08 let us take 74ls08 simple AND gate application circuit as shown below.

In that case, the left button should have a red wire on the lower left pin. Top menu About Us Contact. After verifying the three states, you can tell that we have satisfied the above truth table. If you 74ls08 use 74ls08 pull down resistor, make it low like PeterBennett recommended. If you choose the wrong pair, you end up with an always on switch. Sign up using Facebook. The switch between the input pin and Ground will provide a Zero Ohm connection 74ls08 Ground when 74ls08 switch is 74ls08, ensuring that the gate sees the 74ls08 as a Low.

74ls08 to main content. I think that you were dead on in the first 74ls08 with your answer SaraHeart. By using our site, you acknowledge that 74ls08 have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The four AND gates in the chip mentioned earlier are connected internally 74ls08 shown in diagram below. Sign up using Email and Password.

Next Article Timer IC. As you can 74ls08 the LED is on by default despite neither button 74ls08 pressed.