Re: Are 8255s operating at 3.3V available?

On 17 Apr 2006 00:07:40 -0700, "VSP" <vijayandra.poojari@xxxxxxxxx>
wrote:

Has anyone used an 8255 which can operate at 3.3V ? Is such a device
even available? Or could some one suggest some other chips which can
provide the functionality similar to 8255 but can work at 3.3V?

The 82C55's I've used all require 4.5-5.5V, but I suppose that doesn't
mean someone else might not know of one that works at 3.3V. I'm just
not aware of one.

What kind of timing do you require? Can you specify the set up and
hold times for your memory interface to the chip, etc? The usual
82C55 requires some 150ns or 250ns for the /RD pulse width, and so
on... are you able to meet these timings? More? Less? Do you need
all 24 I/Os? More? Less? Is the 44PLCC packaging usually found for
an 82C55 okay? Have you searched Maxim or Microchip for their port
expanders? Would SPI or other serial interface be okay?

What have you considered and rejected?

Jon
.

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