Logic level refers to the output voltage levels of digital logic, which is often 3.3 V or 5 V.
2
votes
2answers
63 views
Digital out, output low voltage, no load
I'm controlling a home-built current regulator, using a PIC microcontroller (PIC12F1572).
The regulator is implemented using an op-amp and mosfet, and works well. The input to the regulator is a ...
0
votes
0answers
19 views
NOT consistent Euler Paths in logic diagram. What now?
i'm working with non-series-parallel arrangements, something like this:
as you can see, the euler paths in pull-up and pull-down are differents. for example, in pull-up we have "abcde" and in ...
0
votes
2answers
77 views
How do you choose a diode for a 5v to 3.3v clamping circuit
I have a logic input that is 3.3v and I want to be able to allow it to interface with either 3.3v or 5v input signals w/o worrying about it being damaged. I would like to use a resistor with a ...
0
votes
3answers
113 views
Circuit to switch about 5W of 12V using CMOS logic inputs using N-channel MOSFET?
I want to switch some 12V landscape light LEDs, totaling about 5 watts, using MOSFETs.
I thought I had some logic level N-Channel MOSFETs lying around, but apparently not.
What I have is several ...
2
votes
3answers
128 views
Low power serial bluetooth module with Arduino
I plan to use the HC-06 serial bluetooth module with an Arduino Leonardo. To my knowledge, the Arduino's serial pins output at 5V with 40mA of current. The HC-06's datasheet says it will accept input ...
0
votes
1answer
62 views
Connecting separately powered devices via serial
I have a small issue connecting an FTDI USB to 5V Serial adapter to an externally powered PIC microcontroller. They are connected via serial connection. The USB connection powered the FTDI and a ...
-1
votes
2answers
61 views
Where to look for logic level of a circuit in the datasheet?
Whenever I pick a chip for my project, I run through the same chore: finding out if its logic levels match what I work with. Is it 5V? 3.3V? 1.3V? Or one of these that sources whatever level I apply ...
1
vote
1answer
87 views
Is it safe to use a bus buffer as level shifter?
I am currently using SN74ABT5402ADW as a buffer and level shifter for my ADC, however, the datasheet does not explicitly say that it can be used as a level shifter. I provide it with 5V power, but the ...
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votes
3answers
114 views
Should I use CMOS vs. TTL?
Now, I know that this question has been asked so many times that it seems like I'm trolling, but I must point out that I couldn't find the right answer to this question anywhere.
So yeah, CMOS and ...
1
vote
2answers
91 views
Fan in Fan out problem
Fan out is the maximum number of inputs that can be connected to a specific output. Why can’t we connect more number of inputs to this output?
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votes
3answers
72 views
Logic gates not working correctly
So, a few weeks ago I got into digital logic, and thought I'd buy some logic ICs. However, instead of doing actual research about which ones are good and which ones are bad, I just bought whichever ...
5
votes
3answers
556 views
How do I invert a signal without deforming it, and without using a logic gate?
I have an IC which outputs pulses over an open collector pin. I need both these pulses and their inverses in my circuit. I want to do the inversion by using as few as possible transistors and without ...
0
votes
2answers
87 views
Couple questions about logic levels
I have a microcontroller (ATmega328) that runs on 5V and another chip (MAX31855), connected via SPI as a slave (that only using the MISO line), that runs on 3.3V.
Do I need to convert the output of ...
-1
votes
1answer
80 views
BSS138 levelshifter draws 35-40mA current when one side is grounded?
I completely rewrote my question as I found the source of the issue is related to the level shifter only.
This is the circuit for a 3.3V to 5V bidirectional levelshifter, used frequently.
My ...
0
votes
2answers
176 views
How to avoid short circuit when connecting a microcontroller and device using I2C bus?
I am attempting to connect an 8051-compatible microcontroller to an accelerometer using the I2C bus. Both devices operate at the same voltage, 3.3v.
However, I am failing to understand something: ...
1
vote
3answers
262 views
3V3 to 5V level conversion
I'm currently working on the development of some measurement equipment. For conversions I use a small ARM which runs on 3V3 and to display the results I use a graphical display running on 5V. This ...
1
vote
1answer
610 views
Arduino <-> BBB UART issues using bi-directional level converter (5v to 3.3v)
I am having a strange issue interfacing between an Arduino and BeagleBoneBlack over UART.
The Arduino is 5v logic, and the BBB is 3.3v logic, so I'm using a bi-directional logic level converter from ...
2
votes
1answer
51 views
making sense of HCT ACT cmos “addional supply current”
I'm trying to make a low-current level shifter from low voltage (~2V) CMOS up to 5V CMOS.
I had the idea to use TTL-compatible CMOS gates in the HCT or ACT families.
But this line in the 74HCT04 ...
2
votes
3answers
91 views
Sniffing a proprietary data line at 47.5V
I need to sniff the physical layer of a proprietary data line with a logic analyser, but my analyser is limited to 5V input. Unfortunately the line runs at 47.5V, which would fry everything. I ...
6
votes
5answers
7k views
Is there any bidirectional 5v-3.3v level shifter?
Is there any IC that interfaces any 3.3V Input/Output to 5V Output/Input? I need it primarily for an Arduino Due but if there any bidirectional IC that works like that it would be great.
Some people ...
2
votes
2answers
243 views
Control relay from sensor output when LOW is 0.2V
I used this circuit as a reference to drive a relay from the digital output of an arduino. This circuit worked as expected.
simulate this circuit – Schematic created using ...
0
votes
1answer
38 views
GPIO pull up to different level
I am using MSP430F235 which is supplied with 2.5V on DVCC. So, all its I/Os will be in 2.5V level. Now, I want to enable a LDO in which EN pin is tied to a different level (>2.5V is the battery supply ...
2
votes
3answers
233 views
Logic level converter for H-bridge and UART for Raspberry Pi
Here is my situation:
I'm using a raspberry Pi to control a H-Bridge. The H-Bridge is not tolerant of both it's inputs being high logic value, which causes a short through the transistors, bypassing ...
0
votes
0answers
81 views
Force RTL compiler not to optimize the logic
I have a verilog design with an input A which is 128-bit. I would like to use assign statement to let A equals to a fix value.
But I don't want RTL compiler to optimize the logic associated with A, ...
2
votes
1answer
545 views
Is PIC running at 3.3v, 5V logic tolerant?
Can a micro-controller that is capable of running at voltages ranging from 2.3 to 5.5 V, tolerate 5V logic levels while operating at 3.3V?
I need to interface GPS (5V) and raspberry Pi (3.3V) with my ...
0
votes
1answer
317 views
Converting 3.3v logic level to 5v using octal bus transceiver
I'm using the Raspberry PI to communicate with various sensors and other circuits that input and output 5V logic level. The Raspberry Pi itself has 3.3V GPIOs, so i need to convert the logic levels.
...
4
votes
1answer
393 views
TTL logical low isn't ground
I'm working with an Arduino Due and four 5V TTL pressure sensors. I'm using this logic level converter to convert from the 3.3V Due to the 5V sensors. I've been having problems using all four at a ...
4
votes
2answers
2k views
Single transistor level up shifter
I need a simple, single directionnal level shifter for 3.3V -> 5V conversion.
There are many options on the internet, some using a logic ic and some using 2 NPN transistors (converter and inverter), ...
2
votes
1answer
8k views
Step up 3.3V to 5V for digital I/O
I normally use an Arduino for my projects because it has 5V inputs and outputs and has 5V Vin so that makes life very easy when interfacing with 5V components. For this project I want to use a ...
2
votes
2answers
2k views
GY-521 MPU-6050 + Arduino nano - Logic converter or not?
I bought this MPU-6050: link (marked as "GY-521" on the board)
According to the manufacturers' site, the sensor logic level is 3.3V (though the eBay page says ...
4
votes
1answer
134 views
Is the logic level of a MCU the same as the operating voltage?
The Atmega328 has an operating voltage of 1.8V to 5.5V. If I was operating it at 3V (by supplying 3V to VCC) and set a pin to high, would that pin be at 3V?
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votes
1answer
231 views
Sensing 12v inputs in 3.3v system
Sorry if this has been asked before, but I searched for a while and didn't find anything that exactly answered my question.
I would like to sense the "dummy lights"(oil, neutral, etc.) in my ...
2
votes
1answer
367 views
Detect logic signal in a long distance. What type of interface to use?
My daughter board uses a comparator(LM339) to output logic 1 or 0 under a 3v3 supply. The cable connecting daughter board and main board is at least 1.5m. Luckily, the frequency is not fast but the ...
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votes
2answers
299 views
multiply binary numbers [closed]
Is it any book which explains how to multiply binary numbers and how to create appropriate digital circuit schema?(i.e. digital schema which compute the multiplication of the binary numbers).
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votes
2answers
257 views
Translating to “below ground” logic levels
I have an RF switch chip that is controlled by a logic signal with levels of 0 V and -3 V.
I want to control this from a CPLD that's producing ordinary +3.3 V CMOS levels.
Board area is at a premium ...
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vote
3answers
2k views
controlling SPI devices using the Arduino - different voltages
My arduino board uses 5v to power the atmega chip. I was wondering is there any thing wrong with powering my atmega at 5v but say I power my MCP4922 dac at 3.3v does it matter? It just that I've seen ...
1
vote
3answers
291 views
Connecting 3.3 and 5 V devices
The requirements are different from similar questions I've found here.
TXB/TXS are expensive for my needs.
Sparkfun's logic shifter is bi-directional, while I need two uni-directional conversions, ...
3
votes
1answer
646 views
What is the difference between a voltage-level translator and a logic-level translator?
(This is a follow-up to an earlier question of mine.)
I would like to use the GTL2000 bi-directional translator IC to facilitate level translation between a 3.3V circuit and a 5V circuit (including ...
4
votes
2answers
466 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. ...
1
vote
1answer
81 views
what are cores in real in a cpu?
i would like to know what cores at physical level are in a cpu. some mix of logic gates make a head that's called a core is it?.so one core how does it appear to be in physical level.!
PLease am new ...
4
votes
2answers
1k views
Logic Levels between 5(V) and 3.3(V) devices
I am using a 5V microcontroller to communicate with a Bluetooth module operating at 3.3V.
I have regulated the output from the 5V microcontroller rail to 3.3V rail for the Bluetooth module.
Since I ...
4
votes
4answers
584 views
Using an open-collector output from one IC to trigger a level change on the input pin of another IC?
So my problem is simple: I have an IC that provides an output pin to alert you when some condition is met. The output pin is open-collector, high-impedance when active. I want to monitor this output ...
5
votes
1answer
144 views
Need 1-4 pins controlling 16pins logic level
I have max four outputs coming from a PIC. I need these four outputs (or one serially) to simultaneously control 16 pins with a logic level. This is for a clock application.
A BCD could accomplish ...
5
votes
2answers
923 views
Methods to drive a multiplexed LCD with logic-level signals?
I've used such a technique in a couple of the products I've designed, but I've never seen anyone else do so. It's possible to drive a 3-way multiplexed LCD using a bunch of 74HC595's to generate an ...
