Forum Discussion
Altera_Forum
Honored Contributor
15 years agointerface MAX-II with 5V device
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...
Altera_Forum
Honored Contributor
15 years agoAs per reference document downloaded from Altera’s site, can be interface 5V signal to 3.3V operated CPLD using pull up and series resistor connected to IO pin and between two IC, but as per calculation, value of these resistors are very low, approx 200 Ohm, if operating frequency of signal is 40MHz. And if 20-25 signals (16 bit Bidirectional bus and control signal) are connected as above mentioned way then current sinking from VCC is very high. So is it feasible to use this configuration in my application? or there is only way to use level shifter in between two ICs.
Regards, Pankaj