# Questions tagged [level-shifting]

Level shifting is the process of converting between different logic levels. E.g. from 0-3.3 V logic to 0-5 V logic

368 questions
204 views

### Level Shifter Circuit Question

Looking through the internet, I came across following circuit. MCU GPIO generates 0V or 3.3V Level. VDD may be 5V or 30V. I would like to use the same circuit for both purposes, which is to supply ...
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### 0/10V @ 5 mA input ,translated to 0/10V @0,2A output

The idea is a circuit where an analog input 0-10V (max current of 5mA input), reflects into an analog output with a minimum current of 200mA. The voltage of the analog output (Vo) must always be equal ...
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### I2C with 1.8V levels without level shifters?

I have problems detecting an MPU-6050 I2C device on the Intel Edison Mini breakout board (it only supports 1.8V levels). According to the thread here, it might be possible to get the sensor working ...
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### Do I need a level shifter with an open drain output

I'm currently doing a schematic that has an IC that operates at 3.3V (HDC1000 for those curious), and the rest of my digital operates at 1.8V. I have a level shifter for the I2C lines, but there is an ...
316 views

### -5/0 volt to 0/5 volt logic levels?

Does anyone know a good way to convert -5/0 volt logic to 0/5 volt? I'm using a chip as seen in the diagram below, but I'm not sure what to do about the inverted logic levels. Basically, I need to add ...
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### How to blink LED with 1.8V?

I am experimenting with an Intel Edison mini breakout board with pinout like here: http://fab-lab.eu/wp-content/uploads/2014/10/Edison_IO_LED.jpg Now, I soldered header pins to plug the board into a ...
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### How can a GPIO logic to high amp/voltage logic adapter be built using multiple voltages? (5v, 12v, 24v)

I'm working on a project that requires making a fairly universal board (to work on different model machines). I need to hook up many pre existing motors and switches/sensors to the board that all ...
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### Possible to use a voltage level shift IC for Arduino and external IC?

One of my projects require a 3.3V supply. Its an audio codec, TIs AIC3254, to be interfaced with Arduino Uno. The codec requires almost 300mA of current, so was thinking of using a level shifter ...
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### High level logic level

I need to read a high level logic level betwwen 0 to 30 volts on a microcontroller input, is this is correct, thank you
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### Switch (Relatively) High Voltage from Logic Level

The Situation: Basically, I would like to switch a load that requires 30v using a switch that cannot have more than 5v across it. More descriptively, I am trying to drive the anode of a VFD segment ...
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### Level shifting in OPAMP and HE100T01 interfacing problem

Hi, I want to measure current of 0-50A. For that, in my application I am using HE100T01 hall effect sensor which can measure current from -100A to +100A(depending on the direction of flow it gives -...
971 views

### Pull-up resistors required on both side of level shifter?

My I2C sensor and my embedded processor do not agree on the logic level. So I need a level shifter. Normally I would put a pair of pull-up resistors on the SDA/SCL lines. With the level shifter in the ...
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### uni directional logic level conversion with active drive current

I'm trying to connect an EM4095 to a cortex m0. The EM4095 requires an active high drive voltage of min 4V and has an internal pull down of 50K. Additionally it must be low during boot, otherwise it ...
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### Dual (Shift Up and Shift Down) SPI Level Translation

I'm faced with an interesting challenge: I'm using a microcontroller with 3.3 V logic, but I need to use a SPI (4-wire) interface with parts operating at three logic levels, namely 1.8, 3.3, and 5 V. ...
698 views

### Converting 5 volts to 12 volts using a photocoupler

i have an arduino and i need to convert 5 volts to 12 volts in order to trigger a 12 volt Rele, i am considering to use the circuit that i attached here (below), if the "input" square is 5 volts, what ...
941 views

### DAC Signal to AC?

I am producing a sine wave signal from STM32F3 through DAC. but since micro-controllers can not produce negative output so my output limits to positive half only. but in my application i need signal ...
186 views

### How to combine or simplify multiple 5-12V level shifters

I've created the following model for a school project. This is the first time I'm attempting to read sensors or write alarms etc. using a microcontroller. How I can improve it? To me it seems likely ...
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### level shifting options [closed]

I want to translate or shift 1.8V to about 2.5V. Now, there are 2 ways I can go about with it. Use an op-amp based circuit as shown below - Mosfet circuitry - Which is more efficient and why ? In ...
331 views

### How to shift level of my AC signal compared to another AC signal? [closed]

I want to shift my AC signal level. i have a floating point in my circuit (SINE wave 1 with high amplitude around 350v) which is always changing. on the other hand i have another signal (SINE wave2 ...
888 views

### level shifter alternatives using passives

I have always used level translators when communicating between 2 systems(or controllers) of different voltage levels. For eg txb0108 is a commonly used one, among a host of others. Now, why should ...
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### Digital Level Shifter with Op-Amp

I'm trying to design a simple level shifter to read the digital output of a sensor into a beaglebone GPIO. The sensor output is either 0V or the 24V supply voltage, although a different supply voltage ...
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### 5-10V to 3V3 level converter for bidirectional I/O

I need connect 3V3 powered MSP430 family processor and PW0268 ultrasonic sonar IC. PW0268 is powered Vcc 5-11V and is connected with MCU via bidirectional IO pin which is internally pulled up (3.5-6....
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### OPAMP Level shifting problems

This is my first post here. I am facing the problem with level shifting circuit which is later the input for the ADC of the microcontroller. As far as the sine and triangle waves concern circuit is ...
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### Low voltage PWM to logic level PWM

I have a sensor which constantly outputs serial data at very low voltages (in the milli-volt range), however I need to read this serial data using a PIC micro controller. How can i convert this data ...
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### USB to multiple RS485

I'm trying to create a device that will control a few independent RS485 lines using single USB port. My first idea was to use GL850G usb hub controller (4 downstream ports), 4x FT232R, 4x MAX485. I ...
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### High Speed Op-Amp recommendation [closed]

I am tasked with the issue of driving an IC that wants 5V input signals from an FPGA (3.3V outputs). Now, the most daunting part of it is the slew-rate requirements, with rise time \\$t_r = 1.5 \text{...
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### Level-shifted push-pull gate driver speed problems

I am designing a peak detector with a MOSFET as reset switch. I want to drive the MOSFET by the output of a CD4528 monostable multivibrator (voltage vr in the schematic below). When the N-channel ...
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### Is noise a problem when using a logic level shifter?

Good morning everyone, I'm building a device that uses several bidirectional logic level translators to interface 3.3V microcontroller to 5V, 2.5V and 1.8V sensors (via I2C lines). But I wonder if ...
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### Where do voltage level limitations of logic level translators come from?

When browsing through available bidirectional level translator ICs, I always see the condition that reference voltage on one side of the translator must be strictly less than voltage on the other side....
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### Overcoming the logic level translator limitations

Good morning everyone, I have a STM32F407 microcontroller running on 3.3V logic level, and I have a plethora of peripherals that I want to connect to it. The problem is that these peripherals run at ...
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### Level shifting digital signals with a comparator

I'm trying to understand the voltage levels associated with a comparator used for level shifting digital signals. The comparator is the MAX995. The input voltage levels are +1.5V/-2V, and the output ...
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### Level Shifting Arduino 5v to 1.8v

I am trying to level shift 5v from the Arduino to 1.8v. I have hooked up the level shifter as pictured below. However, I am not getting 1.8v from pin A1. Can you please tell me what I am doing wrong?
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### Can I use a line multiplexer as a level shifter as well?

I have 40 x 5V inputs that I want to read using 3V GPIO pins on the beaglebone black. I am planning on using 5 multiplexers (such as the 74HC151 or 74HC251) that will be sharing the 3 select lines. I'...
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### Connecting BeagleBone Black to an Arduino

I am a software guy (everyone immediately downvotes...) trying do the following: (1) On a BeagleBone Black ("BBB") I am driving a GPIO pin high in software. (2) Then I am sending PCM (audio) out ...
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### Logic Level Shifter

I am trying to connect two devices on a PCB. One operates with 3.3V digital high and the other works with 5V digital high. I actually grouped the input and output pins (There is no bidirectional pins)....
114 views

### Can I, Bi-Directional Level Shifter as Motor(3V) controller with Arduino Lilypad (3.3V)?

Basically this could be easily done by using a BJT NPN, but since I want to control two motors(3 V, 45-60mA) and 5 LEDs was thinking of using a Bi directional level shifter instead of using ...
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### How does a bidirectional level shifter work?

I have the following circuit with an NPN HEXFET Q1 (BS170) Correct me if I'm wrong: When the TX-3V3 microcontroller is 3.3V i.e. logical 1, the TX-5V is a ...
1k views

### pull down resistor in PIR circuit

I have an motion sensor circuit. The circuit calls for a voltage of 2-15 dc volts. On the PIR data sheet the source pins calls for a pull down resistor of 47K at 5 volts. My question is if I use 8 ...
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### Why does 3-to-5 volt with transistor not work the way it should?

A quick google for "3v to 5v transistor" gives me dozens of circuit diagrams that look like option A below with a NPN transistor and a pull-up resistor. If I build the diagram in iCircult, it works as ...
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### Logic Level Converter only works reliably when multimeter attached

I have this logic level converter that only lets data flow when my multimeter is set to measure milliamps and the leads are placed across the high and low signal pins. On the low side I have an ...
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### 74HCT244 UART level translator, how would the circuit look?

I am building a UART 3.3V to 5V Level translator between a Raspberry Pi and a ATMega328. The 74HCT244 is my choice of translator but I can't find a good example of of hooking it up. Am I right that ...
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### Clamping Diodes - Any disadvantages form continuously clamp down?

I am looking at using Clamping diodes to protect my Raspberry Pi UART pins from over voltage. The ESD Diodes I am looking at using My question is, is there any harm in them continuously clamping down ...
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### Level shifting 8 output IO Expander from 0V-5V to -2.3V to +2.3V

I have a circuit problem that I'm trying to find a solution for. I have an 8 output IO expander which outputs 0V-5V. It is running analog switches which have a Vdd and Vss of +-2.3V. Using the 5V ...
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### how to increase the voltage of a digital signal?

I'd like my Raspberry Pi GPIO port to communicate with a digital circuit that works at 2x the GPIO voltage. The communication will be at a relatively high frequency (up to 500kHz). The main question ...
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### Bi-Directional Level Shifter Circuit with pull-down resistors

I'm looking for a bi-directional level shifter circuit to interface a 3.3V controller to a 1.8V component which is not 3.3V tolerant. Usually I'm using the well-known level shifter circuit, e.g., ...
570 views

### HIGH speed Level Shifting

I was working on FPGA project that will be able to detect and timestamp input pulses from a series of detectors giving off a 20 ns pulse for each positive detection. Problem arises is two fold: the ...
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### drive a relay from a 3.3v 2mA max output

I need to drive a relay, but my logic signal is limited to 3.3v with a maximum of only 2 mA. Can I use a level shifter? I have a 5V relay with a 125 ohm coil drawing approximately 40 mA. Any other ...
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### Octal buffer/line driver need current limiters?

I have a couple of these http://www.toshiba.com/taec/components2/Datasheet_Sync//149/215.pdf I am using for level shifting 3.3 volts to 5v from a beaglebone to a stepper motor driver. The frequencies ...