SN54/74LS • SN54/74LS • SN54/74LS DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified). S. b l. P. 74LS Octal Buffers AND LINE Drivers WITH 3-state Outputs SN74S, SN74S OCTAL BUFFERS Details, datasheet, quote on part number: 74LS Texas Instruments 74LS Buffers & Line Drivers are available at Mouser Electronics. Mouser offers inventory, pricing, & datasheets for Texas Instruments .
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Home Questions Tags Users Unanswered. Which I have interpreted as: What does “put a led on the 3 output pin” mean?
And when I connect the Vcc pin [ Unfortunately your test is invalid because according to your recent schematic your Vcc supply to the 74LS is only 3.
I have the feeling that I have understood the schematic, but the 74ld241 is this is not working. So I clearly don’t understand at all. Sign up using Email and Password.
And we still don’t know how you have your LED connected???? I have tried other gate 19 with 15, 13, 11 and I have the same behavior. Your explanation “two input are high” sounds more like the definition of an AND gate.
OCTAL BUFFERS AND LINE DRIVERS WITH 3-STATE OUTPUTS
But my led at pin 18 just glow dimly and never change state, no matter if pin 2 is high or not connected. Then [you connected 3. Do you understand what a buffer is and why we use it? Therefore any results you get using a power supply of 3. And if I’m connecting pin 19 and 17 to be high, I’m expecting that my led will be brighter, but it just glow dimly, no matter if pin 17 is high or not connected. I would have guessed the current gain was more than 0.
I’ve done quite a lot of research since first writing this answer, and with unpowered 74LS devices and an input voltage between 0 V and 5. This is clearly what I am expecting. Email Required, but never shown. I was wondering if I didn’t have broke my chip because I don’t have protected the input gate, but it wasn’t asked in the schema.
74LS datasheet, Pinout ,application circuits OCTAL BUFFERS AND LINE DRIVERS WITH 3-STATE OUTPUTS
I don’t know that I’d actually seen a chip manufacturer document the behavior, but I’ve observed it and understood enough about silicon to understand that two P regions joined by an N region form a transistor. But I thought gate like those didn’t need to be datasheeg.
Pull pin 19 high, and the output will follow the input 17 and either the green or the red LED will glow brightly; the other one will be off. Note the invertor symbol tiny o ring at the control gate connected to pin 1; you must pull pin 19 high to activate, and pin 1 low to activate.
I didn’t put any resistors on the input.
JvO 2 MrBonjour Try another gate then. The LED being lit is not a surprise. Do you have 5 volts Vcc connected 74ld241 pin 20, and have pin 10 grounded?
Which I have interpreted as being: