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

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Level shifter for WS2811 led strip

I'm trying to control a WS2811 Led strip with an ESP32. I'm using a logic level shifter to convert the 3.3V output of the ESP32 to 5V. I bought this level shifter (txs0108e) https://fr.aliexpress.com/...
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1answer
102 views

How to speed up level shifter?

I have a level shifter that uses a transistor to control the gate of a high voltage P-channel MOSFET, like this: simulate this circuit – Schematic created using CircuitLab This is designed to ...
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2answers
52 views

10-30v to 3.3v Level Shifting [closed]

Could someone point me towards a level shifter IC or circuit that can handle 10-30v to 3.3v shifting? It doesn't need to be fast or bidirectional just want to data log the state of some 12v and 24v ...
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1answer
71 views

How does a LSF level-shifter work?

I'm trying to interface an Arduino with an eMMC chip to bit-bang it. eMMC uses bidirectional lines, and one of them (CMD) is first used in open-drain mode (for identifying devices on the bus) and then ...
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1answer
42 views

The simplest “adaptive” downward level shift solution?

I want to build a level shifter circuit for the RX pin of my ESP-12S. The goal is to convert any level between 3.3V and 5V to 3.3V as I might use many USB to UART breakout boards with different output ...
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0answers
40 views

How do I wire a Rasberry Pi 3B+ to a WS2812b RGB strip?

I am working on a project where I need to use a WS2812b RGB strip. I am really worried because I have already burnt 2 Raspberry Pis with my wiring. I just want to show my schematics, and be assured as ...
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1answer
64 views

Pulldown for zener voltage shifter

I would like to know whether R24 has been correctly applied to pulldown the EN pin when none of the diodes are switched on. The idea here is that voltages higher than 3.3V may be applied from any of ...
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3answers
55 views

How should I drive a chip where I need to pull pins low in order to enable

I am wanting to use a FSTD16211 in my circuit. It's datasheet says that pins OE1 and OE2 should be high to disconnect the 2 channels of the bus, and both should be low to connect the 2 channels of the ...
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0answers
43 views

Noise filtering circuit on a pulled-up 1-wire bus

The 1-wire bus data line is connected to a microcontroller pin (through a level shifter) with open drain configuration. The bus is pulled up to 5 Volts (DVDD) with a 4.7k resistor. The communication ...
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1answer
52 views

Multiple ground planes, single point ground, and a level shifter

I'm using a level shifter to go from 3.3V to 5V (digital/analog). According to the datasheet, if I put 1 ground on the left side of the IC and the other on the right, it would tie the grounds together ...
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2answers
46 views

High level present in a pin of a non-powered IC can damage it?

I'm using a TXS0108E to convert from 5V to 3.3V and vice versa. The schematic is below: In the datasheet, in section 6, I read the following: Voltage applied to any output in the high-impedance or ...
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1answer
39 views

Can I leave it unconnected pins in the level shifter?

My concern is that pins are connected between DB25 and TXS0108E, but are not connected between TXS0108E and the Header 5x2. There is only the tracks between TXS0108 and the Header 5x2, but there is no ...
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1answer
70 views

Voltage shifter 0-30VDC

I am required to generate and measure squared signal (PWM like). I should cover a 0-30VDC amplitude. High level of the signal is 30 VDC, low level is 0VDC. The bandwith to be covered is 0-20kHz. I ...
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4answers
932 views

Purpose of level-shifter with same in and out voltages

I am looking at a schematic for the Pixhawk 2 board (page 3). The UART ports on the microcontroller are sent through a level-shifter chip (TXS0108) where the input voltage is the same as the output ...
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1answer
69 views

Both sides of a voltage level shifter connected

The TXS 0108E is a level shifter circuit, performing, in my project, a shift level voltage from 3.3V to 5V . Because of a design error in the wiring diagram, I left some pins with the same name on the ...
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1answer
142 views

Understanding 5V to 1.8V UART level-shifting circuit

Hopefully it's OK to ask very basic electronics questions here. I had a TTL 5V UART cable, however the board I had only accepts 1.8V max. So I found some online schematics that uses resistors and a ...
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4answers
74 views

4.5 V on gate of Mosfet while switch open

I have a strange behavior with the circuit below. (the bidirectional logica level should be read as: VL = Voltage Low GNDL = GND Low VH = Voltage High GNDH = GND High L1 = Low channel 1 (I did only ...
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2answers
62 views

Level shifting: from 0-3.5V range to -2/1.5 range

I have a signal (digital) which has output levels of 0V (logic 0) and 3.5V (logic 1). I would like to know if it is possible to shift it between -2V (logic 0) and 1.5V (logic 1). I found here on ...
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2answers
132 views

How to find a truly bi-directional level shifter?

I'm trying to create an interface PCB to a 32 channel USB GPIO device which has 3.3v IO, and I want the flexibility to use 1.8, 3.3 or 5v - across all pins, or at most in 2x banks of 16 - I don't need ...
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2answers
501 views

Level shifter using BJT schematic

I was reading the book Analogue electronic circuits and systems, by Amitava Basak, when I stumbled in this level shifter circuit that uses BJTs instead of the usual mosfets. See the below picture. ...
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1answer
97 views

Using a Dual Bidirectional I2C Bus Voltage-Level Translator

I have a module that uses this ADC powered with 3.3V (MCP3422): Datasheet Now I would like to communicate with it over I2C using an Arduino Mega. The problem is that the Arduino's I2C is operating on ...
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3answers
202 views

Protecting a 3.3V circuit from 5V power supply

I'm designing a dev board for 3.3V parts. On the dev board, I will have a header for an "FTDI Friend" USB-to-Serial converter. The FTDI part can supply Vcc to the target board. However, FTDI parts ...
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2answers
85 views

How can I build a versatile high voltage translator with an output in the negative and positive range?

Looking for advice on how to build an adjustable voltage translator. Input is standard 1V8 logic, but output HIGH is in a selectable range of +3 to -3V, while output LOW is way down in a selectable ...
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1answer
40 views

Digital signal integrity & grounding

I have a battery operated device with an old B&W LCD in it. I'm tapping to the display bus and would like to input it into an FPGA for some processing. The bus includes vertical and horizontal ...
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1answer
153 views

UART RX in VHDL

I have to set up a UART transmitter and receiver using a Spartan 3 board. I've got the transmitter set up already and verified it with the arduino terminal using this FTDI breakout.The receiver is ...
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1answer
95 views

Is my understanding of this level shifter correct

I am considering using this TI LSF0102 level shifter in my circuit - but would like to understand, based upon its datasheet, if I have my understanding correct. It says it has a 100mA current rating, ...
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1answer
131 views

Why is this considered a slow logic level shifter?

I'm working on a project where I have to do some unidirectional logic level shifting. I'm not able to get any chip to do it at this moment (it's late at night) so I looked up some DIY solutions and ...
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2answers
100 views

Is my understanding of this level shifter correct?

I am considering using this TI LSF0102 level shifter in my circuit - but would like to understand, based upon its datasheet, if I have my understanding correct. My aim is to be able to supply 3.3V ...
2
votes
1answer
194 views

Level shiffter (3.3V / 5V) for controlling transistors

Is it possible to control the base of the transistor using the level shift chip (3.3V / 5V)? I want to use the SN74AHCT125 level shift chip. Transistor BC337-16
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1answer
54 views

Weak output from TXB0104 at 1.5MHz

I'm driving a TXB0104 translator from 3.3V logic on the B side, VccB is 3.3V, VccA is 2.5V, OE is on VccA. Both supplies are solid. It's on a breadboard. (https://www.sparkfun.com/products/11771). The ...
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1answer
62 views

Question regarding MCU, Voltages and Level Shifting

I have a board with a 3.3v MCU (C8051F850 from Silicon Labs in a QSOP-24 package) but whose pins are 5v tolerant. The board is running at 5v and all the relevant GPIO pins from Ports 0 & 1 have ...
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1answer
43 views

Mixed digital/analog rails and level-shifting components best practices

I am designing a board with a ±2.5V analog domain and a 3.3V digital domain where space is at a premium. Digital and analog grounds only connect at a single point near the supplies. As such I am using/...
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1answer
376 views

What's wrong with this single-transistor level-shifter?

I was trying to step up the output of a 3.3V microcontroller pin to 5V for communication with another device. I wanted to do it with a single bjt, and found a good design for doing that here Single ...
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1answer
47 views

Can I use TXB0104B bidirectional level shifters on the Intel 8085 NMOS CPU buses?

I want to connect an old Intel 8085 CPU to an FPGA board. The basic issue is that the 8085 works at 5V while the FPGA will not accept any voltage avobe 3.3V so I decided to use the TXB0104 / TXB0108 ...
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1answer
153 views

What's the purpose of using PNP transistors on I2S bus?

What could be the reason of using these 3 PNP transistors on I2S bus (LRCK, BCK and DATA pins)? The DAC used in this schematic is PCM5102. I know for sure that this DAC would work without these ...
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2answers
175 views

What is wrong with this voltage shifter?

I need to do voltage shifting (3.3V Papilio FPGA <--> 5V RAM chip). Most of the pins are output 3.3V -> input 5V, and 3.3V qualifies as "high" to a 5V device, so I can connect them directly. The ...
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0answers
61 views

1.8 V to 5.0 V level shifter with low delay and low rise time

i have a problem with finding the right components and circuit for the following problem. I have a device that is producing trigger signals with a length of 100 ns at a amplitude of 1.8 V (left part ...
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1answer
136 views

How do I remove the offset from the DAC output and change the range?

This DAC has an output range of 1-3 volts. Here's the datasheet: Datasheet I'm getting pulses with different amplitudes, frequencies, duty cycles and widths varying from 0.2 ms to 2 s from the DAC. ...
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2answers
78 views

74AS TTL to CMOS pull up resistor and maximum speed (or lowest delay)

Hello I have to pilot a CMOS input 5V chip device with a 7474 flip flop with the lowest possible delay to minimize clock jitter. Signal is about 11.3 Mhz I have two options: 1) 74HC74 (CMOS ...
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1answer
45 views

Weird level shifting issue only when connected to IC chip

I'm connected to a 5v heat-pump to control it via serial. I'm using a level shifter to shift between the two as the heatpump is 5v and the D1 is 3.3v shown in the scope images below. My issue is I can'...
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2answers
85 views

Convert CMOS-level signal to microphone-level (0..3V --> -1..+1V)?

I'm building a microcontroller circuit that feeds its output into a microphone input of an audio recorder. The output is a square wave. (Think old-style 3.5mm Square credit card readers). What can I ...
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1answer
301 views

Level shifting with 74HC245 3.3V to 5V not working for WS2812b [closed]

I'm trying to drive a strip of NeoPixels/WS2812b using an ESP8266 controller. To do so I'm using an external power supply (5V/10A effectively more like 5.6V) and a 74HC245 to shift the 3.3V data line ...
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2answers
243 views

2.8V to 5V conversion not working as it should. Why?

I'm using an arduino Leonardo clone (SS Micro) who works on 5V logic only, but has also a 3.3V output for powering devices. I'm interfacing it with a breakout board TOF sensor, the VL6180. This ...
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1answer
67 views

Best way to transform multiple digital signals from 12V to 3.3V

I am looking for the best way to transform multiple (more than 10) 12V digital signals down to 3.3V I know some ways to do it, such as voltage dividers, make use of BJT or MOSFETs, or even ...
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1answer
41 views

Automatic level shifting

I have a signal which can have a different offset voltage based on the requirements. However, I need the voltage to start at zero. Since the offset is variable, I was hoping if there are any ...
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2answers
670 views

How to monitor an Alternator exciter wire with MCU?

I have a internally regulated vehicle alternator which uses a conventional battery light wired in-between the exciter terminal and positive. Obviously when the alternator isn't turning the exciter ...
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1answer
98 views

PC to Rasberry Pi Serial Communication

Im trying to communicate to my pc using my raspberry pi using a software called Docklight. I'm using a serial cable (that i ripped apart) and my breadboard as shown below. Now, you can also see I ...
0
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1answer
75 views

Bidirectional Logic Translator translates to 2.8V instead of ~5

Considering the below PCB with the following scheme, with components inserted, with DC+ connected to a relay's DC+, DC- to DC-. When CH1 is connected to the relay, the voltage between HV1 and HGND is ...
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0answers
89 views

Does Level Shifting for I2C also work for UART?

This is a widely used circuit for level-shifting I2C signals that will be familiar to many of us here: simulate this circuit – Schematic created using CircuitLab Can it be used for shifting ...
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1answer
83 views

Active analog attenuation with OPA2340

I wish to have active analog attenuation circuit. Following this page, I got myself some OPA2340. I use the B-side to keep the numbering somewhat intact. I go with the design on Figure 16-2 (p. 14/...