Level shifter 1.8V<->3.3V

[filip.amator]

Hi All!

I am looking for an inspirartion for a level shifter circuit (unidir.) between 1.8V and 3.3V digital systems. Sadly, I can't use dedicated chips - they must be radhard and SEL free and I couldn't find proper products on the market. The only option is to use discrete components. Max. frequency is 10 MHz and rise time/fall time must be 10ns or slightly better. Any ideas?

 

[KlausST]

Hi,

3.3V --> 1.8V: Resistive voltage divider
1.8V --> 3.3V: bjt + pullup

you may also look for comparators and analog switches to build a level converter.

Klaus

 

[danadakk]

Although this link is a bit of an ad for TI part discussed there
are some points made for not doing discrete approach, eg.
power sequencing, isolation, glitch free....

https://training.ti.com/understanding-pitfalls-discrete-level-shifting-circuits


Regards, Dana.