Hey everyone, I'm trying to control a laser with a PWM signal. The laser driver board takes a 5V TTL signal. The only problem is my board that will be controlling it can only do 3.3V PWM. I bought this logic level converter because it was cheap and I figured I would take a risk. I have hooked up …

I honestly have no idea what that means.....embarrassing..... Should have done my research. I mean, it says TTL in the description so I just thought it would work. Can you point me in the direction of a logic shifter that will do what I want?

You could use a simple transistor to convert 3.3v to 5v. Of course you will have to take into account signal inversion if you use a common emitter NPN cct. We need to know what the input signal requirement is for the laser.

I'm not too sure what the input signal requirements are. What I do know is that it's 0-5V PWM and I hooked up an arduino to the TTL port of the laser driver board and I was able to control the power of the laser with the analogWrite command. This is the type of laser driver board. The board will be…

https://www.digikey.com/product-detail/en/texas-instruments/SN74HC125N/296-1572-5-ND/277218 Power it from 5V. Input signal 3.3V, output will be 5V. Make sure you buy 74HC125. 74HCT125 will also work well, maybe better, as a valid high only needs to be 2V, while HC125 needs 3.15. https://www.digi…

I definitely have a fundamental misunderstanding about these signals work. I know the basics of PWM so when the board wants the laser to be at 50% it is sending out a 50% duty cycle pwm signal so I'm reading 1.67V on my multimeter. I expected this because it's the average voltage of the pwm signal. …

To properly measure a PWM waveform, use an oscilloscope.

CrossRoads: SN74HC125N Texas Instruments | Integrated Circuits (ICs) | DigiKey Marketplace Power it from 5V. Input signal 3.3V, output will be 5V. Make sure you buy 74HC125. 74HCT125 will also work well, maybe better, as a valid high only needs to be 2V, while HC125 needs 3.15. SN74HCT125N Tex…

You cannot talk about averaging when you have cheap test equipment (assume it is cheap). You are running into an equipment measurement problem, use a scope.

Yes, input signal will follow output signal. 50% duty cycle in, 50% duty cycle out. 50% of 3.3 = 1.65, 50% of 5V = 2.5V.

How to use Logic Level Shifter to convert 3.3V signal to 5V?

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bluejets March 28, 2018, 1:01am 2

maybe as it is designed for IIC I2C ???

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How to use Logic Level Shifter to convert 3.3V signal to 5V?

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