PWM signal to TTL

Hi, I'm working on a new project where the sensor needs a TTL logic signal.
From the Arduino, I'm looking into outputting a PWM (0-3V) signal but I need to convert this into a TTL logic. Is there an IC or circuity that I can use for this?
Thank you for your help

HI @miteshradia.
Recommendations.
Read: How to get the best out of this forum
Use </> tags to post sketcks or printouts;
Post your scheme. Can be done freehand;
What products are you using in your project?
Which microcontroller you using in your project?
Arduino Uno/Mega/ESP....?

" 'm looking into outputting a PWM (0-3V) signal but I need to convert this into a TTL logic. "

Use a transistor or MOSfet.
RV mineirin

I would use the 74HCT14. There are six inverting buffers in one IC. Just use two, one fed into the other to get your signal. I use this when driving Neopixel strips.

"TTL" logic is actually 0 to 2.5 V, so what you appear to want to do is to convert the "TTL" logic you already have, to 5 V.

The 74HCT14 is the simplest approach as it is specifically designed to convert "TTL" to 5 V logic. That's what the "T" in the type number means.

Bad idea. :roll_eyes: ICs such as the 74HCT14 contain a complete circuit to perform the function. Using discrete components requires a number of components to do the same thing poorly.

Hi @Paul_B

I understood "A" PWM with being 1 PWM.

RV mineirin

Yes so what difference does that make?

Note the 74HCT14 needs to be powered by 5V to give you a TTL logic level signal out.

What??

image

https://www.allaboutcircuits.com/textbook/digital/chpt-3/logic-signal-voltage-levels/

OK, so it's 2.7 V. Or 3.3 V.

Not 5 V because TTL does not drive to 5 V. It cannot. And apparently TTL gates do not like being pulled up to 5 V. (I'll leave Mike to explain that. :face_with_raised_eyebrow:)

The two diode drops on the pull-up strictly limit it to perhaps 3.7 V. Maybe more with Schottky.
Note that TTL used only NPN transistors. :sunglasses:

Because of D1, a pull up to 5V through a proper resistor, of course, would not matter. But, notice that for a LOW input, we must draw current out of the input pin!

So 2.5V has now gone up to 3.7V. Have you actually used TTL in anything? I suspect it was before your time.

Also, can you explain why the inputs don't "like" going up to 5V?

Anyway, of course we agree that HCT is the way to go.

TTL thresholds are compatible with 3.3V logic, 0.8V and 2.4V are the thresholds.
If you are driving TTL from 3.3V CMOS there's no translation to do.

1 Like

That was exactly how TTL worked.

Open-collector devices could be ganged to form a "wired-AND". You didn't actually need pull-ups.

Without pullup this was unreliable and had little noise margin though. Standard TTL pullups are 1k, LS family could use 10k.