Questions tagged [ttl]
Transistor Transistor Logic. Logic circuits built from bipolar transistors and resistors.
563
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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 ...
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74f269 counter getting very hot
Hi I'm a DIY enthusiast and I got stuck with the circuit that I designed.
The counter is getting very hot from the moment It's powered up.
In my setup the 330Ohm resistors at the outputs are ...
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Modbus acquisition timings
Part 1
What is the standard timing method for bits acquisition for a receiver using Modbus RTU?
For example, for UART: "Communicating UARTs have no shared timing system apart from the ...
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Design a relay driver from TTL input with common parts
I would like to drive a pneumatic relay from a TTL GPIO source, the TTL may be 0-3.3v or 0-5v
I would like supply and cut 12v to the relay to control the air.
I have a concept of what i'm trying to do ...
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1
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Is powering the Nuvoton N76E003 with just the UART0 pins legitimate?
I bought an 8 channel USB/UART controlled relay board from banggood.com:
https://www.banggood.com/2-in-1-DC-5V-8Channel-USB-Serial-Port-Relay-Module-UART-RS232-TTL-Switch-Board-CH340-for-Windows-Linux-...
user97497
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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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Combining CMOS and TTL with drivers and Leds with relay driver
I need some practical advice on how to combine different component types.
I designed a circuit with at the heart an up/down counter (74f269) The outputs of the counter are connect to via 330 ohm ...
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DC>DC Isolated Converter (ADuM5401)
I'm in a bit of a quandary as to if I've approached something the right way or if there's an obvious solution I'm missing.
(Sorry for lack of schematic, still WIP).
Goal:
Self-powered isolated USB >...
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TTL to USB (CP2102)(Driving 5V USB)
I have a USB to TTL Adapter. The Adapter uses the CP2102.
I noticed that the CP2102 seems to derive it's power from the USB V+. My problem is that I need to supply power to the USB. The reason is that ...
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Is there an IC that works like the PL2303 for TTL TO USB? [closed]
Is there an IC that works like the PL2303 for TTL TO USB and can connect to android device with driver?
I have search a lot but I did not find such a thing.
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74LS47/74LS247 BI/RBO-pin usage
I am currently playing around with a 74LS247 BCD to 7 segment decoder. The basic usage for decoding works perfectly fine.
But I would like to test out everything this IC has to offer including the ...
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Connecting RS232 GPS Board to Raspberry Pi
I purchased a NEO-6M GPS board to connect to my Raspberry Pi, and when I bought it I didn't realize that it was meant for RS-232 communication instead of UART TTL (which I believe is what the ...
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CMOS vs TTL power and impedance
I need to compare and contrast a CMOS IC with a TTL IC. I've chosen a quad 2 input NAND gate IC, 7400 for the ttl version and 4011 for the CMOS. I'm having a bit of trouble with 2 of the requirements.
...
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Switching characteristics in terms of TTL flip flops
I am a complete novice when it comes to electrical things. Fine at digital logic, haven't done electricity since high school.
I'm looking at flip flops and I've run into something called switching ...
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How can I avoid a clock glitch?
I have a clock with a 50% duty cycle, driving a 3-bit ripple counter.
When Q2 is high, external lines such as address are stable. I want to generate a short read pulse between 50% and 75% of the Q2 ...
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Are TTL to USB converters bi-directional? [closed]
I'm trying to convert 5V TTL signals into USB signals that a PC can read. However, most converters that I'm able to find are defined as USB-TTL converters. Can I convert TTL signals to USB signals ...
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TTL in an RF switch
I am hoping to find help on how to properly connect supply voltage to my switch assembly in order to actuate. My switch has input requirement of +15, -15, GND, and +5V. Also, the 5v logic inputs. ...
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How to prevent short circuit between output pins
I am trying to hack some signals coming from an old computer going to a Floppy drive using an ATtiny1614 microcontroller.
Normally the computer has full control of the signal lines but at some window ...
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How to interface a thermal printer to an Arduino
I've a thermal printer which has TTL, RS232 & a four pin interface. I want to connect it to an Arduino and take printouts with it. It has the following pinouts:
RS232 & TTL
GND
TXD
RXD
DSR
...
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Using USB-RS232 adaptor for USB-TTL connection? [closed]
Seems there are plenty of questions relating going in the opposite direction, but I couldn't find anything that really told me if I could do this..
I have one of these https://uk.rs-online.com/web/p/...
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BJT transistor max switching frequency vs FET in high frequency computer architecture
Why arent BJTs used with RISC architectures to produce very high speed relatively sparse CPUs? My understanding is that BJTs don't have the forward bias gate capacitance requirements of FETs which is ...
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Does the 74LS09 have an adequate internal input pullup?
I want to feed an output of the 74LS05 open collector inverter into one of the inputs of the 74LS09 AND gate. The internal schematics in the datasheet shows that there is an internal resistor and 2 ...
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Custom HDMI-to-( TFT or LVDS ) decoder/driver
I am working on a custom-made handheld PCB based around a PI Compute Module 3+ and one of the hardest steps I have found is how to include an HDMI-to-50pin-TTL driver on my PCB to run an LCD TFT 7&...
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TTL to 232 with no conversion?
I was reading a blog about someone's application to ingest a TTL signal to a device and got perplexed.
The author connects what appears to be a 3.3V TTL signal directly to a RS232 port (and it ...
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Bi-colour LED resistor value
I am trying to calculate a suitable resistor to give about 2mA to the a bi-colour LED in the following configuration:
simulate this circuit – Schematic created using CircuitLab
The LED package ...
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Convert 24 V signal to 5 V with galvanic isolation
I need to make an acquisition card signal (24 V) conversion to TTL signals (5 V) usable by intelligent cards with galvanic isolation.
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2
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Can Bruce Abbott's inverting TTL to +/- 12V level shifter be improved to better frequency response and better matched impedance?
I am working with Bruce Abbott's awesome level shifter here.
Level transformation 0/+5 V TTL logic to +/-9V how to maximize gain and frequency range (DC to 4 MHz)
simulate this circuit – ...
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TTL Gates Power Dissipation Values
I am not finding any datasheets that provide clear information about the power dissipation of some gates of the 74LS series:
08, 02, 04, 00, 32 and 86.
Can someone help?
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How do I build an RC-base negative edge detector, that makes a low pulse on a falling edge?
I keep coming back here searching for an RC-based negative edge detector for TTL levels, that generates a negative pulse on a falling edge. The only place I find this solution is a certain spot in a ...
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Input impedance of TTL driver in a RF switch
I have a RF switch "ZYSW-2-50DR+" which has a built-in TTL driver. So far as I understand, the driver is like a buffer which amplifies the current while keeping the voltage same(unity gain). ...
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