All Questions
Tagged with ttl transistors
29
questions
6
votes
2
answers
4k
views
CMOS vs TTL Logic Gates?
This is probably a simple question but how come CMOS Logic Gates built from Only Transistors is completely different from one that uses TTL Logic (Like BJT's). I know BJT aren't really used anymore ...
user3073
6
votes
2
answers
14k
views
Help between 2n2222 and 2n2222a?
I am thinking about ordering this:
http://www.ebay.com/itm/x100-Fairchild-PN2222A-2N2222A-NPN-Small-Signal-TO-92-Transistors-US-Seller-/171520659038?pt=LH_DefaultDomain_0&hash=item27ef6d8e5e
and ...
- 81
5
votes
3
answers
2k
views
Going from Transistors to Gates to.....IC's?
So I am trying to understand I guess what is probably a basic concept of computers.
I was taking a look at this previous question:
From Transistor to Gates
And it's accompanying link:
http://www.cs....
user3073
5
votes
4
answers
6k
views
Switching relay with a PNP and TTL levels
I can not wrap my head around the fact how I can drive a relay (24V, 160ohm) with an tip32a PNP transistor which has TTL inputs from a controller.
I can easily calculate my resistors when I use the ...
- 464
5
votes
2
answers
617
views
TTL NAND gate analysis
I was looking into Millman's Microelectronics book, 2nd edition, pp. 245 - TTL NAND Gate.
I am a beginner in electronics and was looking into this book just because of an assignment problem about a ...
- 153
5
votes
2
answers
602
views
TTL NOR Gate analysis
I'm looking at the design below. I am reading this webpage where the picture came from.
What I'm aiming at is the wisdom behind the design. Looking at the two transistors facing downward, I assume ...
- 317
4
votes
1
answer
12k
views
TTL NAND gate (totem pole) current and voltage analysis
I am working on a few practice problems for my course and I am unsure about my working throughout.
hoping for some feedback and guidance from the community as it's not my strongest topic.
Here is ...
- 87
4
votes
2
answers
19k
views
TTL, Totem Pole vs. Open Collector Output
What is the difference of these two ttl nand gates?
What is a totem pole, what does it do and what is it used for?
When connecting multiple ttl logic gates together is it better to use one or the ...
- 53
4
votes
1
answer
471
views
Why are bipolar transistors often used with the base at vcc?
I often find transistors used as shown below. Note that the BJT to the left is being used in a strange configuration, where the base is being pulled permanently high.
What on earth is the transistor ...
- 1,465
3
votes
2
answers
3k
views
Working of a transistor in a TTL inverter circuit
I was referring to TTL inverter circuit in the book Digital fundamentals by Thomas Floyd and its working principles first proposition went as follows:
When input is HIGH, Base emitter of Q1 is ...
- 55
2
votes
2
answers
1k
views
Clock Pulse from Audio Signal (Laptop Headphone Jack)
Been fiddling with some circuits on breadboard to get a stable clock pulse from an audio signal via a laptops headphone jack.
Reason 1: Other precision sig gennies are out of the budget right now
...
- 21
2
votes
1
answer
188
views
Turn on/off a LED using a D-FF and a transistor
I'm trying to control a LED using some microcontroller and I designed a circuit using a D-FF and a transistor to handle it. It looks like this:
So I can control when to turn it on or of by simply ...
- 21
1
vote
1
answer
339
views
Using TTL logic, is it better to use a JFET or MOSFET switch for power?
Using a 3.3V (max. 8 mA) output pin off an Intel Galileo development board, I need to turn on and off a 18V DC motor. Is it better to use a JFET or MOSFET transistor?
1
vote
1
answer
41
views
Interface higher voltage signal to 5 V pull down input signal circuit using discrete hobby components
I have a microcontroller, TTL logic that expects its input to be connected to the ground via a brake lever to tell the microcontroller that the brake has been applied. I believe it uses an internal ...
- 286
1
vote
1
answer
348
views
Shift register that can source +-15V?
I need to source +15V or -15V resp. on several pins (20+) using a few TTL level pins (SPI, I2C, serial) from my microcontroller. Only one of the pins will source +15V at a time, the rest are -15V.
I ...
- 11