Questions tagged [ttl]
Transistor Transistor Logic. Logic circuits built from bipolar transistors and resistors.
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What is the methodology behind 555 timer design?
Small circuits in TTL and RTL we could do intuitively, without any methodology. But what about a complex circuit like 555 timer?
If it was designed using logic gates, it could be easily deduced by ...
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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
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History question - why are logic levels inverted between TTL and RS232?
I'm just looking for a historical answer as to why TTL and RS232 don't transition logically in the same directions. The signals are the same, but basically level-shifted and inverted.
Was there a ...
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What does "limit of 1 TTL LS load" mean?
If I read that a line has a limit of 1 TTL LS load, does it mean that I can attach only a TTL gate? I know that other options exist, for example, the HC, however, in the case I have only LS gates, how ...
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Should I calculate a resistor value for driving indicator LEDs from TTL outputs?
Traditionally I have always used a \$1\:\mathrm{k\Omega}\$ resistor as a current limiting resistor for driving an LED direct from a TTL (or 5V CMOS) output. I can't remember how I came by this value -...
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Active pull-down in LSTTL totem-pole output
The lower totem-pole transistor of a LSTTL IC frequently has an active pull-down from base to emitter (ground). Here is an example from TI's SN74LS93 datasheet.
I was curious how this active pull ...
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Is interfacing the 5V TTL UART with 3.3V microcontroller via voltage divider possible?
I need to connect my MSP430 microcontroller (3.3V) to interact with a 5V TTL UART camera (http://www.cn-lcf.net/sdp/561974/4/pd-2909996/7575433-2127043/LCF-23M_OV528_Protocol_RS232_Camera_Module.html)....
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Can I connect TTL gates directly to the address bus of a Z80 CPU?
I need to know when the 14 MSB bits from the address bus of a z80 CPU are high. To do so my first idea is to use 4 74LS08 ICs (TTL AND gates) reading those lines but I don't know the maximum amount of ...
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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 ...
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limit duration 1pps signal
As a beginner in electronics, I would appreciate very much to get some input from you folks for my project, so I can decide in what direction to point my nose :)
What would I like to do?
I would ...
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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
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Looking for a device to "pass through" or "make high impedance" 8 bits based on one control bit
I need a thing (preferably a single IC) that has 8-bit input, 8-bit output and a control bit, with this behaviour:
If the control bit is active, set output bits to the inputs (no need to actually ...
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Why do TTL pulse generators generate an asymmetrical square wave (unlike CMOS)?
I've read that the asymmetrical (about 1/3 mark-to-space) output waveform is due to input gate characteristics of a TTL inverter, but I want to know more about which characteristics of the TTL input ...
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IC takes no input (or high) as high and low input as low on breadboard
I was working with IC 7400 (or LM74LS00 / NAND) (and IC 7486 - XOR) to design and verify combination circuits and logic gates.
Consider the lower end of breadboard as LOW (connected to GROUND) and ...
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How to build a noise generator based entirely on logic gates?
I would like to build a noise generator based on logic gates. It could be white noise generator or a random bits generator that sound similar to a noise source. I need a circuit recommendation or an ...
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