Re: 3.3V-5V level ****fters

langwadt@[EMAIL PROTECTED]
 wrote:
> On 25 Sep., 21:08, Joerg <notthisjoerg...@[EMAIL PROTECTED]
>
> wrote:
>> qrk wrote:
>>> On Wed, 24 Sep 2008 17:26:32 -0700, Joerg
>>> <notthisjoerg...@[EMAIL PROTECTED]
> wrote:
>>>> What's the jelly-bean level ****fter du jour, the most popular?
>>>> Need to ****ft three sigs 3.3V to 5V and another three 5V to 3.3V.
Stuff
>>>> us analog dudes normally don't do. The TXB0104 looks ok, so does the
>>>> 74LVC4245. But the specs for both are horrible, incomplete at best.
Not
>>>> much in drive levels mentioned, or just for one direction.
>>>> The topper is a comment in the TXB spec, "OE should be tied to GND
>>>> through a pulldown resistor; the minimum value of the resistor is
>>>> determined by the current-sourcing capability of the driver" That
driver
>>>> is obviously on the chip. Duh! Of course they also forgot what to do
if
>>>> not needed. Pull up? Leave open? Who knows. Well, maybe they had a
>>>> kegger the night before ...
>>>> Here's what seems to qualify as a datasheet these days:
>>>> http://focus.ti.com/lit/ds/symlink/txb0104.pdf
>>>> VOH and VOL at 20uA. Microamperes! Couldn't believe it.
>>> Going from 5v to 3.3v is easy with Fairchild 74LCX541 and other parts
>>> in the family. I've found that Fairchild seems to have more
>>> interesting parts in jellybean digital, power FETs, and analog
>>> switches.
>> AFAIK those are only 5V-tolerant but can't really drive 5V logic with
>> gusto on the other side.
>>
> 
> something like this then
http://www.fairchildsemi.com/ds/74/74LVX4245.pdf
> ?
> 
> it has dual supply, one for each side
> 

Yep, or the LVC4245 I wanted to use.

-- 
Regards, Joerg

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