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

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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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4answers
98 views

High Speed Op-Amp recommendation [on hold]

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 ...
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3answers
26 views

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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2answers
68 views

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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1answer
51 views

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 ...
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68 views

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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2answers
54 views

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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47 views

Connecting 3.3V periperals with 3.3V or 5V MCU

I'd like to connect various 3.3V perpherals to works with either 3.3V (i.e. Arduino Due) or 5V MCU (i.e. Arduino Atmega2560). Here is a basic diagram: The system is consists of two parts: ...
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6answers
239 views

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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4answers
43 views

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. ...
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1answer
59 views

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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67 views

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 ...
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2answers
37 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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1answer
58 views

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 ...
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3answers
124 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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47 views

Level shifter vs Translator…bits, channels and outputs per channel

I'm looking to do 3v3 to 5v to allow a micro to control a set of servos but I'm having a hard time with the marketing terminology... What's the difference between a level shifter and a translator? ...
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2answers
127 views

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 work as ...
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2answers
81 views

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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2answers
111 views

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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1answer
90 views

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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45 views

Vbe multiplier logic shifting

I need to shift 5V form to 3.3 for USB communication. Is it possible to use Vbe multiplier instead of 3V3 Zener diodes simulate this circuit – Schematic created using CircuitLab
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2answers
79 views

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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3answers
793 views

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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1answer
161 views

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., ...
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1answer
66 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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21 views

Is SN74CBTD3861PWR or alike available in DIP? [on hold]

I need to find some DIP IC to bidirectionally shift 5v-3v for FPGA interfacing. I have found that SN74CBTD3861PWR is more than capable of doing that. Is there any IC like this, except in DIP? Thanks ...
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37 views

Advantages of integrated level translator

I've been trying to decide on what level shifter approach to use for a single, bi-directional, slow signal going from 5V to 3.3V. My input could be a switch to 5V, or maybe a logic level output. ...
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2answers
159 views

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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2answers
49 views

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 ...
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1answer
182 views

Voltage shift from 3.3V to 12V

I'd like to use MX-FS-03V 433MHz transmitter together with a Raspberry Pi (RPi). The Raspberry Pi's outputs have 3.3V, but the MX-FS-03V operates on 3.5-12V (the higher the voltage the higher the ...
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3answers
161 views

Voltage shift from 5V to 3.3V

I'd like to use MX-05V 433MHz receiver together with a Raspberry Pi. The MX-05V operates on 5V, but the Raspberry Pi's inputs only allow 3.3V. So i need to shift the RX data output level from 5V to ...
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2answers
227 views

Need help with a VU meter analog signal

I am making an Arduino VU meter. I need to convert an analog AC audio signal to a varying positive DC signal. I would like the following outputs: 2.5 V output at 0 V input (from VM1); 5 V at maximum ...
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1answer
167 views

I2C level converter stops bus [closed]

I am trying to get an lcd 16x2 with PCF8574 I2C working with my arduino due. If i connect my lcd with 3.3v (backlight doesn't work, led from the PCF8574 lights up) and upload the i2c scanner sketch ...
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1answer
80 views

using transistor to switch 3v from 2

i need to use a GPIO pin to test whether an LED is on/off. the LED only has 2v power which is not enough for my digital input (3.3v) so i would like to use a transistor to amplify the voltage from 2v ...
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79 views

Increasing voltage swing of totem pole structure

I have a totem pole transistor pair as seen in the schematic below which consist of Q1 and Q2. This totem pole is driven with 5V pulses because of the limitations of the opto-isolator. My aim is to ...
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145 views

Synchronous MOSFET Driver for Inverting Buck-Boost topology

I'm on project to make Inverting Buck-Boost converter. that digitally controlled using microcontroller by using feedback on ADC and send duty cycle with specific frequency on PWM pin. I'm using ...
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2answers
406 views

Linked grounds produce “noise” on Arduino's 5V lines

I'm using an Arduino to realize two "simple" tasks. The Arduino shall receive messages by an 433MHz receiver and send them via ESP8266/ESP-01 to a server. The schematic/wiring plan is attached below. ...
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2answers
96 views

SD card logic levels

I'd like to use an SD card using an SPI interface. My microcontroller uses GPIO logic levels of 2.8V. Do I need a level shifter, or can I connect the card directly? I've had a look at the Physical ...
0
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1answer
103 views

Shrink ADC signal from 5V to 1V?

I have an ADC signal, how do I shrink it to 1V from a 5V sensor like Hall IC for example. Of course, a resistor divider is one method, but will it work reliably as the output is expected between 0 to ...
3
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2answers
456 views

Level shift circuit MCU to MOSFET

I have a H-bridge that is being supplied by 12V and using around 10A. I am turning it on/off with a microcontroller that has an output of 0V-5V. The switching frequency is "super low" so the gate ...
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0answers
40 views

How to fix Serial 0 Level not fully grounded

My project uses a USB to Serial(5V) converter board. Looking at the Serial signals on a Scope I noticed that the 0/GND level signals are very high. They are nice and squire but consistently around ...
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1answer
124 views

When is voltage level shifting needed/unneeded?

I know the question sounds simple, but I am facing an edge case here. I have a microcontroller with 3.3V on the GPIO's. I want to use it with this LCD panel. Adafruit creates their own breakout board, ...
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3answers
121 views

Best way to read 18kHz PWM signal with wide V_pk-pk (5.5-18V)

I am trying to design a circuit for level-shifting a PWM signal coming from a sensor and reading it with a 5V micro controller in an automotive environment. I will run my design by an EE at the end ...
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1answer
123 views

How can I increase the multiplier of a voltage doubler circuit using IC4049?

I replicated a voltage doubler circuit from this example I found online: ... and as expected, I am getting 12V from a 6V input. I would like to increase the multiplier to more than 2x, but I am ...
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3answers
185 views

Instrumentation Amplifier Level Shifter

I am working on a temperature measuring circuit using a pt100. The input of my instrumentation amplifier (AD8226) is between 80-200mV. The Gain is set to 20.84 so I get an output range of 1.7-4.2V. I ...
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1answer
64 views

SPI Clock Frequency changes when level shifted

I'm using Adafruit's TXB0108 bi-directional 8 channel level shifter with my Arduino Uno. The SPI clock from Pin 13 is level-shifted through the first channel of the level shifter. Measured with my ...
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3answers
255 views

Logic level shifting from 5v to 2.8v and vice versa

I need to use a logic level shifter in my circuit which translates 2.8V logic level into 5V and the other way round. I found this document. The device itself is presented on the page 10. It is very ...
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1answer
69 views

Level shifter circuit with 50 V output

I am looking for a level shifter circuit, that can convert 5V to 50V logic. I've been looking through some designs. I see a lot of designs uses a current mirror for this. And was wondering, what is ...
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4answers
2k views

Level shifting 5V to 3.3V - can I just use a zener diode?

simulate this circuit – Schematic created using CircuitLab My problem is the ATmega328 is running at 5V. I know I need a bidirectional level shifter. However don't really want to spend ...
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1answer
80 views

Why level-down shifters

I am considering a dual-Vdd circuit design, Vdd_H is 0.6V, Vdd_L is 0.35V. I understand that I need level-up shifters to convert the Vdd_L domain signals to Vdd_H signals, to have enough drive. While ...