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28 Pin eeprom chip switch

pietercc

Mar 19, 2024
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Mar 19, 2024
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New here, not sure if this is the right category for this, I am looking for something to make it easier to swap in between two 28pin memory chips, as in have the 2 pugged in, and just have a toggle between the two. The chips I am looking to swap between are both 27sf512, Not sure what else to say, just curious if someone can point me in the right direction.
 

Martaine2005

May 12, 2015
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Hi, you may be able to simply stack them and ONLY switch the VCC.
Or if on perfboard, use sockets for the ICs and only switch the power input (VCC)?

Martin
 

Harald Kapp

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Nov 17, 2011
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ONLY switch the VCC.
I beg to disagree.

That'll leave the unpowered switch with logic signals at the inputs. Undefined behavior will be the case.
Better to switch the [imath]\overline{CS}[/imath] signal like so:
1710915065956.png
This is how it's meant to be connected. The inactive Chip will drive its outputs to a high-Z state and thus will not disturb the output signal from the active chip.
 
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