Discussion in "Project Help" started by    sakibnaz    Jul 28, 2019.
Sun Jul 28 2019, 06:40 AM
Hi All.

I need to connect my MCU with an external SPI device which have Logic levels of HIGH 3V and LOW 2V. From the Device to MCU Logic shift I can convert the Voltage 3V/2V to 5V/0V respectively using LM339. But I am facing problem in the other direction conversion of 5V/0V to 3V/2V.

Can anyone advice any comparative Circuit or IC which I can use to make the LOW Output a Positive Voltage (i.e. 2V)? It will be great if there any Quad Differential Comparator available.

Thank you in advance.


[ Edited Sun Jul 28 2019, 10:32 PM ]
Sun Jul 28 2019, 08:55 PM
An LM339 may not be fast enough for reliable SPI operation.
Logic shifting is often done with FET transistors.
Search ebay for "Logic Level Converter" for ready made packages.

[ Edited Sun Jul 28 2019, 08:58 PM ]

Get Social


Powered by e107 Forum System


Wed Apr 14 2021, 09:31 AM
Niklas Spearman
$99 once off!
Tue Apr 13 2021, 10:42 PM
Aliza Dyal
Brand new way of online advertising just released! The best part is you'll never have to pay for clicks again! To find out more have a look at : http://bit.ly/advertising-with-zero-perclick-charges-ever
Tue Apr 13 2021, 07:29 AM
Mon Apr 12 2021, 11:54 AM
Joe N
I have recently launched my own site, and I am looking to provide value for you for free, by giving away 26 professional level blog post templates (worth $297).
Mon Apr 12 2021, 09:24 AM
Hey, I think your site might be having browser compatibility issues. When I look at your website in Ie, it looks fine but when opening in Internet Explorer, it has some overlapping. I just wanted to give you a quick heads up! Other then that, very good blog! https://onanadiete.ru/alpha-numeric-reasoning-questions-and-answers-pdf.pdf alpha numeric reasoning questions and answers pdf alpha numeric reasoning questions and answers pdf



Thu Jun 25 2020, 03:46 PM
Mon Jun 22 2020, 03:03 PM
Tue Jun 16 2020, 05:10 PM
Sat Jun 13 2020, 09:43 PM
Thu May 21 2020, 12:44 PM
Thu May 21 2020, 01:28 AM
Wed May 20 2020, 07:05 PM
Wed May 20 2020, 11:52 AM


Guests: 135, Members: 0 ...

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 38215
Newest member: Mirza123