Transistor Transistor Logic. Logic circuits built from bipolar transistors and resistors.
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45 views
How could I efficiently implement this “TTL load”?
I'm attempting to test a parameter of an IC to the specifications listed in the data sheet. The data sheet describes the following load circuitry for the output:
The data sheet notes that CL be ...
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3answers
129 views
7805 5v Regulator outputting 5.8v? TTL chip not functioning correctly? LED + TTL chips?
I've read a number of other similar questions to mine, but none of the answers have helped me so far. I also don't have any electrical schematic software, so I'm afraid I'll have to explain in words ...
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0answers
41 views
Low latency TTL from a PC?
I need to sync some computation with an external device that is triggered when the computer completes. I am expecting to generate a 1hz triggering clock and was hoping for stable latencies within 1ms. ...
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2answers
72 views
What should be considered when sizing trace widths for digital logic signals?
For traces that carry a static DC current, it's pretty easy to calculate the minimum trace width based on the required ampacity of the trace. However, I'm not sure what should be considered when ...
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3answers
156 views
Will a 3V3 rated UART be damaged by applying 5V signals?
If I have a device specified for 3.3V operation and I connect a 5V level TTL signal to it ? Will it's UART ports be damaged or not ?
I have a WiFi module and I want to know if its UART ports will ...
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2answers
86 views
Digital Clock --->Bad Accuracy (Help to Troubleshooting)
INTRODUCTION:
I'm a student in the Electronic Engineering program at my University. I'm building a digital clock as a self initiative to learn more. Some of the requirements and steps that is ...
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3answers
197 views
Driving LEDs / other small loads with a 74HC06 or similar inverter
I was recently reverse-engineering some firmware (and other bits) from a router, and spotted that the front panel LEDs were driven from a 74HC06 hex inverter gate chip rather than a proper LED driver.
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2answers
413 views
What does a two overlapping circles symbol mean in an electrical schematic/diagram?
In the datasheet for a A3503 Hall Effect Sensor, I saw a circuit diagram labeled 'Functional Block Diagram', and it shows a symbol I have not seen before. It's shown here between 3 - Output and 2 - ...
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3answers
136 views
Drive Fight on 7400 Series
I'm currently designing a 7400 series circuit to drive LEDs from a set of shift registers (74595). Each shift register's tri-state input is wired to the output of a 2:4 decoder (74139), and the ...
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1answer
134 views
How to get a CVBS signal into an TFT LCD Panel over TTL
I have a TFT LCD panel from Chi Mei, namely G104V1-T01 on which I want to show a PAL composite video signal. As the datasheet tells me, this panel uses TTL (as opposed to LVDS) for data transfer, so I ...
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2answers
112 views
Synthesize VHDL into discrete TTL integrated circuits
I've got a small project in VHDL (fully working in a Xilinx FPGA) and I would like to implement it using an old-school printed circuit board and discrete TTL integrated circuits, in the spirit of ...
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2answers
110 views
Gating TTL UART Tx pin to simulate BREAK for arbitrary time periods
I need to gate a TTL Tx pin @115000bps as the chipset that drives the RxTx lines do not implement UART BREAK for arbitrary time periods.
Thanks to this community's feedback (Selecting proper vales of ...
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2answers
379 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 ...
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2answers
222 views
Interfacing 3V TI MSP430 to PC serial port
I am scratching my head to figure out a possible soloution for this scenario:
I am developing a simple application using TI MSP430 microcontroller. The microcontrol part is powered by 2xAA batteries. ...
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2answers
197 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
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