I need help picking Bi-directional Logic Level Converter

[MasterLight]

Hello,
I'm new to the RPI and IC community, and would like an experienced advice/help.
I am looking for Bi-directional Logic Level Converter (preferably the contacts supports SPI)
2.2v <--> 3.3v
3.3v <--> 5.5v

if you are using/used it before and recommend it, please leave a link of the item below.

Thank you.

background:
i'm going to connect my RPI to two different memories, which works at different Vcc (2.2, 5.5).
connecting protocol: SPI.
freq speed: 1-15Mhz

[FTrevorGowen]

Hello,
I'm new to the RPI and IC community, and would like an experienced advice/help.
I am looking for Bi-directional Logic Level Converter (preferably the contacts supports SPI)
2.2v <--> 3.3v
3.3v <--> 5.5v

if you are using/used it before and recommend it, please leave a link of the item below.

Thank you.

background:
i'm going to connect my RPI to two different memories, which works at different Vcc (2.2, 5.5).
connecting protocol: SPI.
freq speed: 1-15Mhz

5.5V seems a "little odd" but then I've not worked with SPI memory chips. I suspect you need a module using something like the TSX0108E chip ('J' here: http://www.cpmspectrepi.uk/raspberry_pi ... dules.html ) which, IIRC, can handle your levels (check the datasheet). All of the other modules I've used (and shown in the same webpage) are for 3.3V to 5V level conversion (and vice versa).
Trev.

[MasterLight]

Hello,
I'm new to the RPI and IC community, and would like an experienced advice/help.
I am looking for Bi-directional Logic Level Converter (preferably the contacts supports SPI)
2.2v <--> 3.3v
3.3v <--> 5.5v

if you are using/used it before and recommend it, please leave a link of the item below.

Thank you.

background:
i'm going to connect my RPI to two different memories, which works at different Vcc (2.2, 5.5).
connecting protocol: SPI.
freq speed: 1-15Mhz

5.5V seems a "little odd" but then I've not worked with SPI memory chips. I suspect you need a module using something like the TSX0108E chip ('J' here: http://www.cpmspectrepi.uk/raspberry_pi ... dules.html ) which, IIRC, can handle your levels (check the datasheet). All of the other modules I've used (and shown in the same webpage) are for 3.3V to 5V level conversion (and vice versa).
Trev.

Thank you.

[fchk]

My advice is: Don't use a bidirectional level shifter at all, unless you have a very good reason and know what you're trying to do.

The automatic direction control on such chips is somewhat sensitive and can easily be tricked into a false direction, just by using a pullup or pulldown for example. Others have weak driving capabilities regarding to high level, especially those meant for I2C.

A good choice for SPI are the 74AVC*T(2)45 and 74LVC*T(2)45 families, where * is one of 1, 2, 4, 8. They are small, fast, and they just work. These translators have manual direction control, which is what you want for SPI.

fchk