Questions tagged [ttl]
Transistor Transistor Logic. Logic circuits built from bipolar transistors and resistors.
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What is the shortest pulse a controller can count?
I want to count short LVTTL pulses (about 20-25 nanosecond.)
Right now, I use an Arduino with four IN74AC161N binary counters, but this solution has some Arduino limitations.
I count pulses, send the ...
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Tying open-collector outputs to TTL inputs
I know that open collector outputs are effectively either 0 V or high-Z.
I also know that TTL chips tend to read a disconnected output as high, but that really you should have something like a 1 kΩ ...
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Why does the TTL NAND gate use a 4 transistor design instead of 2?
Why does the TTL NAND gate use 4 BJTs to make the gate when it could be done using only 2?
I assume that the design with the 4 transistors amplifies the current so multiple levels of gates can be ...
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Fan-Out Calculation on LTSpice
I need to find the fan-out of the circuit below. This is a Schmitt Trigger TTL NAND Gate. How can I exactly find the fan-out of the given circuit using LTSpice or calculate it theoretically?
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I'm designing a 4-bit GPU and I need some suggestion about the RAM for it [closed]
I'm working a 4-bit GPU, the GPU run on 1.023MHz (1023kHz) clock while CPU only run on 127kHz so I need a screen buffer for it when the CPU is working on some instruction. The display I use is a 24 x ...
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TTL voltage drop
I recently bought a lot of TTL components like 8-bit registers, bus transceivers, etc. to build an ALU and 2 registers. My issue is that when I build a register, the voltage drops to 4.2, sometimes ...
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How can I find reverse current of 74lsXX integrated circuit
I'm using 74lsXX ICs for my 4-bit computer. I noticed that 74XX ICs have reverse current at the input; I know that the output of the IC allow the reverse input current flow back to it.
But I'm a bit ...
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Can MAX485 TTL-to-RS-485 module be used as UART-to-RS485 module?
I'm trying to make a bridge from Modbus til Home Assistant using an ESP8266 (as outlined here), which uses an UART-to-RS485 module.
I have this MAX485 TTL to RS-485 Interface Module.
I'm not competent ...
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I have a JK flip-flop circuit that works in simulation, but not with real components on a solderless breadboard
I'm building a control mechanism for a seat heater in my car. Eventually, it will drive power relays to control the current to the heating elements. It works in a simulation on simulator.io, but it ...
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How do you make a three input NOR Gate function as two input NOR Gate?
Hi this is my first question!
So I'm clearly a beginner in electronics and studied for months, now the topic I've studying is logic gates and boolean algebra also the TTL ic. I've been curious if how ...
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Logic level converter from 29V to 5V schematic
Does it looks a good schematic to do a proper 29 V to 5 V logic level conversion, any improvements or suggestions?
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Connecting a GPS to computer: Jackson Lab LC_XO serial TTL to RS232 port on computer motherboard
I am trying to hook up my Jackson Labs' LC_XO GPS disciplined oscillator (GPSDO) to my computer motherboard COM/serial port so I can talk to it and for it to send back NMEA messages. Basically, I am ...
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How to connect RS232 level shifter?
I'm trying to use this:
https://www.sparkfun.com/products/449
to connect my RPi to my computer via a USB to serial device. (And eventually connect the RPi to other legacy serial devices)
My questions:
...
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SIM800L V2 not responding to AT Commands from Putty over USB-To-TTL PL2303
My SIM800L V2 RoHS (the blue one) although it connects to the network and registers just fine, it's not responding to AT commands sent over the PL2303 (USB-STC-ISP) USB-To-TTL Adapter through which it'...
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Is there a problem with a resistor inline between two TTL gates?
I want to adapt the output of a board to drive additional logic instead of an LED. The driver board has a current limiting resistor before the signal is routed to the connector. Is there any problem ...
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