All Questions
Tagged with level-shifting ttl
22
questions
0
votes
4
answers
349
views
Level shifting from 3.3V to 5V not working: voltage drops when attaching load
I am trying to trigger a laser using an Arduino. I used a power supply to determine that the laser needs a 3.5V (or higher) signal, at which point it draws around 2.2mA from the power supply. When ...
0
votes
2
answers
354
views
May I connect the RO and DI pins of a MAX485 module directly to ESP32 pins?
I'm running my MAX485 module board with an external 5V power supply, with the R0 and DI pins from the module connected directly to the ESP32 pins, which running at 3.3V. Both grounds were not tied ...
- 31
2
votes
2
answers
410
views
3V oscillator to 5V µC with an 74HCT inverter (12.8 MHz) - bad idea?
I'd like to use an AVR (ATmega328P-AU to be precise) in combination with a fairly accurate oscillator for timing purposes. I stumbled upon the fact that oscillators which have greater accuracy mostly ...
- 33
3
votes
6
answers
1k
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Reduce 3.3 V-8.4 V signal to 3.3 V input
I have a digital input signal which can use anywhere between 3.3 V and 8.4 V to signal "1", and I need to make this safe for a 3.3 V input on a microcontroller (RP2040).
I currently have a ...
- 131
0
votes
1
answer
320
views
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:
...
- 357
0
votes
1
answer
324
views
8-channel/octal equivalent of 74HC125
I have a 12v powered 16-channel relay board, that required 5v logic level signals to control the relays. However, I am using a Raspberry Pi to control this, which has 3.3v logic level outputs. I have ...
- 103
0
votes
0
answers
98
views
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 >...
- 1
2
votes
2
answers
478
views
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 – ...
- 1,541
0
votes
3
answers
2k
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Raspberry Pi with 74HC14 connecting to LED strip (WS2812B)
This might be a stupid question, but I can't seem to figure out how to convert 3.3V to 5V with the 74HC14. I have a power source which can supply 5V (see the power adapter at the left), and use it to ...
- 137
2
votes
3
answers
631
views
74AS TTL to CMOS pull up resistor and maximum speed (or lowest delay)
I have to pilot a CMOS input 5 V chip device with a 7474 flip-flop with the lowest possible delay to minimize clock jitter. The signal is about 11.3 Mhz.
I have two options:
74HC74 (CMOS compatible) ...
- 461
0
votes
1
answer
261
views
5V to 3.3V Converter
I have a problem in connecting Raspberry PI to an MCP3202. I am using MCP3202 at 5V and knowing that raspberry pi works on 3.3v. I have found a solution to convert from 3.3V to 5V using 74HCT244.
And ...
1
vote
4
answers
758
views
Shifting a 2.7V digital signal to Arduino logical levels?
I'm pretty much a beginner in electronics and I'm currently working on a personal project, where I have a device, that is putting out a digital signal (square wave) that goes from 0V - 2.7V and I need ...
- 109
7
votes
1
answer
1k
views
Capacitors in MAX 232
Out of curiosity, can I replace the electrolytic capacitors in the circuit with non-polar ceramic capacitors? Will I get the shifting in level?
MAX232 datasheet: LINK
1
vote
0
answers
670
views
RS-232 Level Shifter
Most PCs don't have RS232 built-in anymore. So the only option is USB-2-RS232 adapters or RS232 PCI-E card. While I expected the adapters to output a low voltage it turns out most RS232 PCI-E card ...
- 11
0
votes
1
answer
931
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Capacitor in RS232 level shifter. Data is strictly half-duplex
I have created a level shifter very similar to the schematic at: http://picprojects.org.uk/projects/simpleSIO/ssio.htm except for the capacitor I use 47nF because the page claims:
at high bit rates ...
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