Questions tagged [3.3v]

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3.7 to 3.3V regulation

I want to power up my ESP32 with LiPo battery. LiPo Battery has voltage between 3.7 to 4.2V and ESP32's operating voltage range is 2.2 to 3.6V (but I want it to be 3.3V) and it consumes around 600mA. ...
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3 answers
86 views

Is it possible to increase the current of an Arduino Nano 3V3 pin without altering the voltage?

I am trying to use an ESP8266 with an Arduino Nano but I see that the NANO can not enough current for supplying ESP8266 from 3V3 pin. I think it is limited from the faactory. If I use the 3V3 pin RX ...
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ADS1115: Using 5V supply instead of 3V, do I need to increase the logic level signal from 3V to 5V?

I am using a microcontroller that has a 3.3V Logic level output. The microcontroller is connected to ADS1115 via I2C pins, and the ADS1115 can be powered with 3.3V or 5V depending on the range of ...
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1 vote
1 answer
82 views

Can I directly connect a 5V DC device to the inputs or outputs of a 3.3V microcontroller that tolerate that voltage level?

I'm doing a project with a PIC32 that works with 3.3V and that has some terminals that are tolerant to 5V levels. I need to manage another device that has a UART at TTL voltage levels (5v). The ...
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3 votes
2 answers
88 views

3V3 PSU Redesign. Noise issues

Our initial design was using the TPS560430 chip as a step-down converted from a Vin of (12-16V) down to 3V3 with the 3V3 rail looking like this (Vpp is 120mV, sorry for the quality): Because of the ...
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1 answer
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Non Inverting switching 24V with 3.3V signal using a mosfet

We have a reset circuit used in a peak hold amplifier. under normal conditions, a capacitor on the peak hold circuit is grounded by RST1 (see Circuit). P0-0 is fixed 24V voltage from the supply. When ...
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2 votes
2 answers
119 views

Understanding a SMD Motor driver IC (heat dissipation and control)

I am designing a circuit to control a 12V, 3A electric pump. I thought the driver rz7899 is very handy. The datasheet gave me the following doubts. Is it ...
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1 answer
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Can RFM98PW 3V3 Regulator Cause Heating

I'm using RFM98PW RF module that is supplied by 5 volts. This module has SX1278 on board which is supplied by 3V3. So there is a 3V3 regulator on board. As you can see in the diagram below there is a ...
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1 vote
0 answers
78 views

CAN Transceiver circuit problem with TJA1042T/3

I am a novice designer who recently started designing circuits. Using the STM32f407VGT MCU operating at 3.3V, using the CAN1TX(PB9) CAN1RX(PB8) pins, the circuit was configured by referring to NXP's ...
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353 views

stm32 nucleo 3.3V usage

This is probably an easy question. When using an STM32 Nucleo powered by a 5V power supply, can I use its 3V3 pin to supply 50mA? Or do I need to use for instance a 3V3 linear regulator attached to my ...
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2 answers
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splitting ground plane

I have a 4 layer board, where I have a 3.3V STM32 and some 3.3V components, and also a 24V H bridge to drive a 24V DC motor. The board is supplied with a 24V DC power supply, the 3.3V is created by a ...
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1 answer
2k views

Raspberry Pi Pico 3.3V_EN pin control voltage inquiry

I am trying to turn on or off a Raspberry Pi Pico using a Raspberry Pi Model 3. The Raspberry Pi Pico seems to have a 3.3V_EN ping which is basically the 3.3V regulator enable pin (3V3_EN) pulled up ...
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1 answer
246 views

How to choose a resistor value for Wheatstone bridge such that it is a balanced circuit?

I have a 3V sine wave input and I want to measure resistor precisely from 1 ohm to 40ohm. I have tried using Arduino to measure the resistor using voltage divider but it became obvious that I will not ...
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1 answer
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How can i turn a DPST button in to a DPDT?

How can i turn a DPST button in to a DPDT? I've replaced all the stock rocker switches in UTV, got all 14 of them done except for one all to Push Buttons. The push buttons are SPDT, "on/on" ...
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-2 votes
1 answer
294 views

Can I drive a motor directly with GPIO pins?

I have a Raspberry Pi Zero with a DC motor attached (directly) to gpio. According to the Raspberry Pi Foundation: The operating voltage of the GPIO pins is 3.3v with a maximum current draw of 16mA. ...
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4 answers
255 views

Convert digital 12V/7V inputs to 3V3 levels

I'd like to read the digital inputs of my alarm sensor into a microcontroller (mainly PIR and Reed switches). The alarm system and the sensors operate at 12V (actually a tad higher) and the MCU uses 3....
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2 answers
134 views

Step up 3.3V to 5V and draw 500mA without a voltage collapse/break down

I would like to step up 3.3V from my power supply with the help of a dc-dc-boost converter to 5V and then I want to draw 500mA by placing a 10 Ohm resistor between the output-pin of the boost-...
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1 vote
2 answers
486 views

Recharging a lipo battery while using it

Right now I am designing a circuit that will charge a lipo battery via usb, using the mcp73831 (at 100mA). The battery voltage(nominal 3.7v) will be regulated to 3.3v to power a microcontroller like ...
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0 answers
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MOSFET for 3.3v MCU

I'm building a custom board with ESP32-WROOM-32E that can supply 3.3v trough the GPIO. I need to power a screen using 3.3v power. I'm looking for a way to power off the backlight using the GPIO pins ...
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-1 votes
1 answer
135 views

How to change breadboard power supply output voltage?

I recently bought a 3.3/5v power supply like this. I'm powering it with a fresh 9 volt battery and 9 volt to barrel connector cable. Right now, it's on 3.3 volt mode, and I have no idea how to switch ...
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0 votes
1 answer
69 views

Diode instead of LDO

For a cost sensitive application we need a 4V supply for a GSM module and a 3.3V supply for a STM32 MCU and couple of sensors. Would it be possible to use a diode like 1N4148 to drop from 4V to supply ...
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-2 votes
1 answer
127 views

How to use the human body as a battery?

I was wondering if you'd be able to extract 5 volts (or even just 3) from the human body. I recently discovered in an experiment that just putting a wet strip of aluminum foil over your forehead can ...
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1 vote
1 answer
185 views

Powering the Raspberry Pi zero from printer PCB

I want to convert my simple printer into a network printer with CUPS on Raspberry Pi. I tested everything with Raspberry Pi 4 and it worked perfectly. Now, I want to fit my Raspberry Pi zero inside ...
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1 vote
1 answer
92 views

Using the same ESP8266's GPIO for 3.3v and 5v

I am designing a pcb which should receive various types of sensors. The microcontroller is an ESP32 and the external input are RJ11 linked to I2C GPIOs of the uC. I have already planned a LevelShifter ...
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2 votes
1 answer
71 views

Driving a 5V LED on computer chassis with 3.3V

My add-in card uses a pair of pins to drive an external activity LED, with anode "provid[ing] 220 ohm pull-up to +3.3 V". However, the LED that I wish to drive with these pins, is designed ...
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2 answers
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3.3V Regulator Overheating

Here is my circuit For some reason my 3.3v regulator is over heating. The regulator is a TLV1117LV33. I've tried everything to try and debug the problem but can't seem to figure out what's wrong ...
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1 answer
754 views

Connect two pins on AD009-01T without a relay

I have an IR chip where I want to shortcut two pins (PA2 and PA0) when told so by a 3.3V Arduino. I could do this with a sort of relay, but I want a better way. I thought, that one of the pins needed ...
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6 votes
3 answers
948 views

Change voltage without consumption

Is it possible to change voltage without consuming power? I have a 5V Arduino circuit that makes use of a wireless chip (NRF24L01) that runs on 3.3V. My current approach to get 3.3V out of a 5V source ...
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  • 199
3 votes
3 answers
204 views

USB2 powering 3.3V at 500 mA

I have the above simple requirement, and I'm frankly astonished that I can't find it as a simple chip. My understandings: USB2 provides 5V on its power pins; USB2 assumes 100mA, but will provide ...
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1 answer
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Connecting a TCXO to logic buffer

I am trying to connect the O/P from TCXO (FOX Electronics FOX924B. 20 MHz, 2.5 PPM, 3.3 V supply, Output HCMOS VOL = 0.5 V and VOH = 80% of VDD) to 74HC240 buffer, which I am also running at 3.3 V. I ...
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1 vote
1 answer
80 views

load resistor - my setup is valid?

i want to test my output current of transistor 2N3906. I have two questions. Is my setup valid to measure the max load of the (2N3906) transistor? One plug of multimeter is on leftmost pin of PNP ...
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1 answer
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My node mcu isnt turning on when connecting 3.3V to VIN [closed]

So I'm trying to wire my node MCU using in with 3.3V and in the multimeter, it's reading the 3.3V being delivered properly by the converter, I also tested for amperage and its consuming 37mA and I don'...
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  • 305
0 votes
2 answers
241 views

Power on/off 30-50mA module with 3.3V Arduino-like GPIO

In my Arduino 3.3V project I have a problem shutting down a GPS module. When it "sleeps" with a command, it comsumes 2mA which is way too much for my project. To my understanding I have to ...
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1 answer
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May I connect 3.6v Li-pol accumulator to 3.3v dc supply?

I have an old Bosch electric owen which has clock and timer on-board. The problem is: on each electricity fail (even milliseconds) this clock resets to the time edit mode and zummer starts to make ...
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0 votes
3 answers
409 views

Mixing 5V Sensors and Devices with 3V3

I'm a programmer, not a wizard. I've read up as much as I can, including the similar questions list from this question, but, they blew by me pretty quick. So here we go: A project I'm doing some ...
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0 votes
1 answer
87 views

Atmega32u4 on 5V. MISO from IC on 3.3V?

I'm running an Atmega32u4 on a 5V circuit. However, I'm also using a Bluetooth IC [MDBT40] on a 3.3V circuit that I'm setting down from 5V with a linear regulator. I'm turning both SCK and MOSI to 3....
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1 answer
214 views

High speed logic level converter circuit

I have been trying to make a 3.3V circuit controlled by an Arduino (5V logic.) I have used a logic converter circuit similar to the SparkFun/Adafruit ones. My problem is that whenever i try to ...
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1 vote
1 answer
211 views

Protecting a 3.3V board against a 5V programmer

I'm designing a home automation board with ATmega328. For programming it I'm exposing the appropriate pins via the AVR ISP interface. Now some ICs of the board allow only up to 3.5V power. What are ...
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3 votes
2 answers
211 views

VUSB / +5V selector to safely power KNX project

I'm working on a board that will include a TP-UART IC + an ATMEGA328-AU on the same device. I'm now facing the potential risk of damaging the host computer or the TP-UART IC if I'm mishandling the ...
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1 vote
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On/Off latching circuit with a raspberry GPIO 3.3v

I'm currently failing solving my problem. Of course if I would good better in electronic, I would not post my question here but that's life, and any help would be appreciate. Context: I have around 50 ...
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0 answers
43 views

Calculation of the resistors values in a voltage divider

I'm working on a circuit where a 3.3v flash memory, which comunicate with SPI protocol, has to be interfaced to an 8-bit PIC microcontroller working at 5v. For the MISO signal there should not be any ...
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1 vote
1 answer
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Diode OR or transistor OR circuit?

I need a circuit that converts a 3.3V signal into a 24V signal. But I also need to be able to activate the 24V signal using a PCB switch. I can do it in two ways, using a diode OR or using a ...
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1 vote
0 answers
31 views

Send a 60Hz trig signal over a 9m cable

I want to send a trig signal over a 9m cable, the signal is around 60Hz (each 15ms it sends a 1ms pulse). In order to avoid electrical interference I convert the 3.3V original signal with the ...
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-1 votes
2 answers
1k views

How to do serial communication between 3.3V and 5V devices using THT components?

I know that there are many questions dealing with logic level conversion/shifting between 3.3V and 5V devices, but my goal is to do do this with standard breadboard parts, so either discrete parts or ...
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1 vote
0 answers
63 views

ADC IC I2C problem

I'm trying to run ads7924 using stm32f series. But i2c does not work so I check the i2c line. Between 0R, MCU side 3.3V but ads7924 side 0V. I set pull up setting of MCU internally . What is the ...
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0 votes
1 answer
200 views

Interface 24V signal from one device to 3.3V signal on another device

I have a device A that sends a signal through an optocoupler, this signal travels through a 7m cable and is used by another device B that has a SN74LVC1G17SingleSchmitt-TriggerBuffer powered by 3.3V, ...
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  • 245
1 vote
1 answer
417 views

ATtiny13A on 3.3V not working

I'm trying to get the ATtiny13A to run on 3.3V which, if I'm not wrong, would be possible. I've programmed the chip using an Arduino Uno. I'm doing a simple blinking LED example and when I power the ...
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0 votes
1 answer
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Can you power a 3.3 led with an arduino 5v output?

I have a led that can handle 10 milliamps at 3.3v. Can I use a voltage divider and a plus resistor to power it from an arduino nano 5v digital pin? Maybe something like this. simulate this circuit &...
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1 answer
262 views

Bidirectional 5V-3.3V level shifter and ADS1115 resistor implementation reduction

I’m using the ADS1115 with 5V because my measuring device provides 0 to 5V measurements but since the microcontroller is not tolerant to 5V, I need to shift it down to 3.3V. I plan to use the BSS138 ...
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0 votes
2 answers
72 views

Getting different measurements from power supply vs a battery

to start with, I am very new to the hardware side so don't beat me up too much. For a project I am doing I need to build a couple power rails, one 3.3v and another 24v. The power supply will be from a ...
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