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Voltage converters

Altera_Forum
Honored Contributor II
‎08-25-2009 01:04 PM
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I'm doing a circuit with a Cyclone III, it expects inputs from comparators that are 5V powered. What is a cheap, low latency (less than 100ns at least) solution to shift that to 3.3V to keep the FPGA happy? 

 

Baldur
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Altera_Forum
Honored Contributor II
‎08-25-2009 01:28 PM
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You can use 5V-tolerant buffers, such as the 74lvc241 (http://www.standardics.nxp.com/products/lvc/datasheet/74lvc241a.pdf). 

Having comparators with open collector outputs is also an alternative.
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Altera_Forum
Honored Contributor II
‎08-25-2009 02:41 PM
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100ns is rather slow. A resistive divider can do.

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