Are XS1 devices 5V tolerant ?

Technical discussions around xCORE processors (e.g. General Purpose (L/G), xCORE-USB, xCORE-Analog, xCORE-XA).
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BEBDigitalAudio
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Are XS1 devices 5V tolerant ?

Postby BEBDigitalAudio » Tue Dec 28, 2010 10:36 am

Hi all,

before I destroy something, I would like to get the following confirmation : when I look to page 14 of the XS1-G4 datasheet, I see that max input voltage is 5V (for 3.3V I/Os)

Can I consider this as "inputs being 5V tolerant" or shall I consider it as a maximum limit, with a normal input voltage of 3.3V ?

Thanks by advance
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Berni
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Postby Berni » Tue Dec 28, 2010 11:21 am

Yes they are 5V tolerant. But remember that this is only for the G devices! The L chips are 3.3V only
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BEBDigitalAudio
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Postby BEBDigitalAudio » Tue Dec 28, 2010 3:28 pm

Thanks Liltroll, this confirms what I understood

And since the 3.3V MIDI is not very standard, this avoids me to integrate a 3.3V/5V level converter in my design

However, it's funny that Lx are not 5V tolerant (I would have expected that the chip design was the same, with same transistor geometry, but it seems that it is not the case)
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Berni
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Postby Berni » Tue Dec 28, 2010 5:06 pm

Umm im not Liltroll anyway...

It may be something with the smaller manufacturing process used on the L series that makes them much more power efficient.

Oh and btw to get 5V output you need to switch the pin in to a input and have a pull up get it to 5V so that means you cant use any fancy clocking on that pin. Oh and btw isn't MIDI current based?
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BEBDigitalAudio
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Postby BEBDigitalAudio » Sun Jan 02, 2011 10:34 pm

LOL I am sorry Berni, I am discussing so much with Liltroll that I see him everywhere now ;)

Yes, MIDI is current based, but the output buffer shall be powered under 5V (or the resistors must be changed, but in that case, the design is not 100% compliant)

And the optocoupler I use for the input requires a 5V power supply on the output side.

I could design something that uses voltage translators (or even make the 5mA current loop of MIDI work with 3.3V, but I am so lazy... :oops: )
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Berni
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Postby Berni » Mon Jan 03, 2011 7:37 am

Well you can always stick a cheep PNP on the 5V rail and do it proper. Everyone has some spare transistors laying around.

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