Level Shifter

[Ed]

Hi,

I need to convert between 3.3V and 5V and vice versa. Does anyone
know of any chips that will do this? The chip has to be a standard
DIP package.

Thanks for any info,

 

[Luhan Monat]

Ed wrote:

Hi,

I need to convert between 3.3V and 5V and vice versa. Does anyone
know of any chips that will do this? The chip has to be a standard
DIP package.

Thanks for any info,

Hi,

I dont know about a chip that does this, but I have had to do it for a
project. There are some cases that dont require much hardware.....


5v open collector to 3.3 volt input: just add a pullup resistor.

3.3 open collector to 5 volt input: same, just add a pullup.

3.3 to 5 volt ttl level or 74hct serieas cmos: just connect, levels are
ok. This will not work for 74hc or cd40xx parts (at least not reliably).

5 volt ttl/cmos to 3.3 input: wont work unless input specified to work
if driven overvoltage. Maybe using a 2-10k series resistor to limit
current would work in most other cases.

Regards,
Luhan

 

[Jimmy]

I ve done the 5 to 3.3 conversion just by using a voltage divider. Belive
the values were 2k from the 5v out put tothe 3.3 input and 10k from 3.3v
input to ground. You might have to play with these values a little.


"Luhan Monat" <luhanknows@yahoo.com> wrote in message
news:ASClb.66900$La.43578@fed1read02...

Ed wrote:
Hi,

I need to convert between 3.3V and 5V and vice versa. Does anyone
know of any chips that will do this? The chip has to be a standard
DIP package.

Thanks for any info,

Hi,

I dont know about a chip that does this, but I have had to do it for a
project. There are some cases that dont require much hardware.....


5v open collector to 3.3 volt input: just add a pullup resistor.

3.3 open collector to 5 volt input: same, just add a pullup.

3.3 to 5 volt ttl level or 74hct serieas cmos: just connect, levels are
ok. This will not work for 74hc or cd40xx parts (at least not reliably).

5 volt ttl/cmos to 3.3 input: wont work unless input specified to work
if driven overvoltage. Maybe using a 2-10k series resistor to limit
current would work in most other cases.

Regards,
Luhan