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Bus voltage translation

S

Steve Minshull

Jan 1, 1970
0
Hi

What IC (or IC family) would you guys recommend for translating from a
3.3V logic level to 5V logic level? I have 3.3V logic on a DSP board
and 5V CMOS logic on a connecting daughter board. It's a 16 bit bus.

Thanks in advance

Steve Minshull
 
P

PeteS

Jan 1, 1970
0
Steve said:
Hi

What IC (or IC family) would you guys recommend for translating from a
3.3V logic level to 5V logic level? I have 3.3V logic on a DSP board
and 5V CMOS logic on a connecting daughter board. It's a 16 bit bus.

Thanks in advance

Steve Minshull

What speed are you running the interface at?

Is each signal unidirectional?

If they are all unidirectional signals, and the 5V board has TTL
compatible inputs, you don't need to do anything from the 3.3V -> 5V
domain.

In the other direction, you can either use a device with 5V tolerant
inputs (most of the 74AHC range) or just use a resistive divider for
relatively slow signals.

If everything's high speed, then a translator may be better

Here's TI's offerings - others (Philips, Fairchild, OnSemi) make them
as well

Dual supply:
http://focus.ti.com/paramsearch/doc...avigationId=11385&family=logic&paramTable=yes

Single supply:
http://focus.ti.com/paramsearch/doc...avigationId=11385&family=logic&paramTable=yes

Translating bus switches if you have bidirectional signals:
http://focus.ti.com/paramsearch/doc...avigationId=11385&family=logic&paramTable=yes

Cheers

PeteS
 
J

John Larkin

Jan 1, 1970
0
Hi

What IC (or IC family) would you guys recommend for translating from a
3.3V logic level to 5V logic level? I have 3.3V logic on a DSP board
and 5V CMOS logic on a connecting daughter board. It's a 16 bit bus.

Thanks in advance

Steve Minshull

SN74ALVC164245 is an absurd part number, but it works fine.

John
 
S

Steve Minshull

Jan 1, 1970
0
Cheers for the help

I've found a dual supply bus translator from fairchild which should do
the job.

Steve Minshull
 
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