AVR-Chat

The main advantage is high input Z and low output Z.  I've used the
resistor divider 3.3V/5V matching design on circuits up to 40KHz transfer
rates with no problems.  If you use smaller value resistors (well under
10K) then unless you have some WAY high line capacitance things will work
out fine at even higher frequencies.  If you are talking MHz clock rates
then you should indeed look into "high input impedence, low output
impedence" type drivers to assure good signal states.  The OP was talking
to a low data rate transceiver, but that transceiver (if I remember
correctly) can have a high burst rate comm speed (in the 1MHz range), so
if he runs it that fast he should use a driver, under 100KHz he's almost
certainly safe with the resistor divider method IMO.

DLC

> This has no real advantage that I can see for level
> shifting. Rather than this, just use a transistor/fet and a
> pullup resistor. With one of these, you still need a pullup
> and you have used two transistors. It is still inverting
> like a single transistor would be, which makes neither of
> these very useful for simple in-line level shifting.
>
> Jim
>
>
> On Mon, 22 Jan 2007 08:55:00 -0000
>  "sm5glc" <lasse.moell@swipnet.se> wrote:
>> http://en.wikipedia.org/wiki/Sziklai_pair
>>
>> --- In AVR-Chat@yahoogroups.com, erikc <firewevr@...>
>> wrote:
>> >
>> > David VanHorn wrote:
>> >
>> > > You can also use a Szaiklai pair, to convert the 3V
>> outputs to 5V
>> rails
>> >
>> > What?
>> >
>> >
>> > --
>> > erikc
>> > --
>>
>>
>>
>
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