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Can MAX-II series CPLD interface with 5V operated device and operating frequancy is 40MHz?
e.g. Interface a Microcontroller (operated on 5V and oscillator 40MHz) data bus with 3.3V operated MAX-II CPLD.
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Read the MAX II handbook:
http://www.altera.com/literature/lit-max2.jsp p73 of the PDF indicates 4.6V absolute maximum voltage for inputs. So no, you cannot interface directly with 5V.
However, you could use a 3.3V powered, 5V tolerant, buffer on signals from the micro to the CPLD (eg., Fairchild and TI TinyLogic devices). The 3.3V signals from the CPLD to the micro will be fine, no buffering required. If you have a bidirectional bus between the CPLD and micro, then use a bus-switch. You power a bus-switch from a diode drop below 5V (giving about 4.3V) and the bus switch will clamp signals to about 1V below that level, i.e., the 5V signals will be clamped to 3.3V (eg., TI, Fairchild, and Pericom).
Cheers,
Dave
Honored Contributor
