AT90S8515-8 with 3.3V supply

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I want to know if anyone have expiriences how the 5V version of AT90S8515 will behave in 3.3 V environment. Because the 3.3V version is hard to get I would like to change it with 5V version in my new design.

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Hi,

The AT90S8515-8 has an operating voltage span of 4.0-6.0 Volts
The AT90S8515-4 has an operating voltage span of 2.7-6.0 Volts

The difference between these two parts, is the maximum operating frequency. The -4 device has a max. freq of 4MHz, while the -8 device can run at 8MHz. The low freq part can operate at lower voltages than the high freq part.

This does NOT mean that you can run the AT90S8515-8 at 4 MHz and expect it to behave at 2.7 Volts, because the part has not been tested for this!

As far as I know, there should be no problem getting the AT90S8515-4. Have you contacted your distributor lately? There's was a time when the AVRs were on allocation, but this dark age is now over :)

Have a look at your local distis at: www.atmel.com/atmel/contacts

Morten, AVR tech. support

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Often times 3.3V parts use the exact same die as the 5V parts. The only difference between the parts is how they were tested. As you lower the supply voltage, the maximum operating frequency will drop (that's why the lower voltage parts are dereated down to 4Mhz). Chances are good that you can operate the 5V device at the lower voltage as long as you observe the derated operating frequency. (this is for prototyping, I would insist on having the properly speced part for production).
I personally used a 5V 8051 type processor at 3.3V. It worked flawlessly in dozens of proto boards.

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