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

0
votes
3answers
122 views

Positive Level Shift a Clock Output using Diode?

I need to level shift a 26mhz 1.8v clock output by .7v on both the high and low side (so clock swings from .7v to 2.5v on output). Would a simple diode/resistor setup like below work for this? ...
0
votes
3answers
63 views

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/...
2
votes
2answers
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 ...
5
votes
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 ...
0
votes
2answers
53 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 ...
0
votes
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 ...
0
votes
3answers
176 views

Driving capacitance with a high voltage level shifter

I am having issues with a 'high' voltage level shifter I am creating. I need to drive a 28Vpp waveform with specific timings ( <.1us rise time, 1us pulse width), converting from the 3.3V logic that ...
2
votes
2answers
2k views

How to scale and shift voltage signal?

I want to scale and shift my voltage signal by below relation: $$ V_{out} = \frac {10} {12} \cdot V_{in} - 10 $$ Indeed my primary voltage is from 0v to 24v and I want to put it from -10v to +10v. ...
1
vote
2answers
281 views

Issues using an Ultrasonic Sensor with Raspberry Pi

I am conducting a project which needs to use a precise ultrasonic sensor but I am having trouble working it with the raspberry pi. The sensor I’m using is the Senscomp 600 series; the manual isn’t ...
0
votes
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 ...
1
vote
2answers
4k views

What can I replace a BSS138 N-Channel MOSFET with?

I'm replicating this level shifter by Sparkfun but they use a transistor that I don't have. Frankly, I know next to nothing about transistors so reading the specs is way over my head at this point. ...
5
votes
1answer
1k views

Odroid XU4 and Olimex MOD-IO by I2C via level converter

Long version Like some of you, I do electronics as a hobby and I'm relatively now to this, so I have a few questions regarding the communication between my Odroid XU4 and a nice I2C module from ...
1
vote
0answers
41 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 ...
4
votes
2answers
5k 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 ...
0
votes
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 ...
0
votes
1answer
455 views

How does a level shifter shift the DC level of a multi-stage amplifier output to the ground (or zero)?

As we can see that input fed to this amplifier is the output of final stage of a multistage amplifier and if we apply KVL to base-emitter loop then Vbb is the DC level acquired from the previous ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
1answer
142 views

SPI readings always high (1) when connected via bi-directional level shifter

I am trying to read two gas sensors (MQ4 for methane and MQ7 for carbon monoxide) with my NodeMCU ESP8266. Both sensors require 5v (for the heaters) and have 4 pins (GND, VCC, DO, AO). Digital outputs ...
1
vote
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 ...
1
vote
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 ...
0
votes
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 ...
2
votes
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 ...
3
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
1
vote
1answer
378 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 ...
0
votes
2answers
520 views

Analyzing 24V fast PWM signal in Arduino

I am currently trying to fit a 3d printer head on a cheap chinese CNC mill. So far I have successfully been able to control the fan, heating element (including reading a thermistor) and the feeder ...
2
votes
2answers
274 views

Is this a reasonable design for a high-speed level shifter?

I wanted to try designing a device that will use an RS-232 interface. RS-232 works at +12/-12V - I know I can use a MAX232 as a level converter, but I wanted to try designing my own (this is a ...
1
vote
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 ...
8
votes
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. ...
3
votes
3answers
2k views

Replace BSS138 with AO3400A in level shifter circuit

I have to use level shifter circuit to interface MAX31855 with Arduino running on 5V. I found easy to build level shifter circuit at SparkFun website. It is using BSS138 (datasheet) which I don't ...
1
vote
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
0
votes
2answers
2k views

FET level shifter for serial does not work with inline resistor for safety

For a voltage change on a serial line I'm using a common level shifter design which uses a FET (BSS138 in this case) as so: I have two of these - one for RX and one for TX. I should add that I'm ...
1
vote
1answer
96 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, ...
1
vote
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 ...
1
vote
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
1
vote
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 ...
24
votes
1answer
22k views

Is my MOSFET-based bidirectional level shifter insane?

In a moment of cheapness, I decided not to order a 5v to 3.3v level shifter from Sparkfun, but instead to put it together myself. The original schematic used a BSS138 MOSFET, but since I enjoy ...
-1
votes
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 ...
0
votes
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/...
0
votes
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 ...