fala
Full Member level 5
Hello board, I read in an article by "Keith Armstrong" that for fast TTL
(rise time 2ns or less) I should consider impedance matching for nets longer than 15Cm. I have an AVR(ATMega128) master MCU @16MHz that it's SPI runs at about 1Mbit/Sec. I want to connect it to 8 slave MCUs which are placed in other PCBs, total distance will be in the range of 40-60Cm for each Slave MCU. In datasheet of my AVR fall /risetime of SPI interface has been assigned
"TBD" which I'm not quit sure what it means(maybe To Be Determined....). anyway if we consider it as fast logic do I need impedance matching? for reliable communication? Dose placing just a resistor at source can alleviate the problems? do I need impedance match for tracks?
Thanks,
(rise time 2ns or less) I should consider impedance matching for nets longer than 15Cm. I have an AVR(ATMega128) master MCU @16MHz that it's SPI runs at about 1Mbit/Sec. I want to connect it to 8 slave MCUs which are placed in other PCBs, total distance will be in the range of 40-60Cm for each Slave MCU. In datasheet of my AVR fall /risetime of SPI interface has been assigned
"TBD" which I'm not quit sure what it means(maybe To Be Determined....). anyway if we consider it as fast logic do I need impedance matching? for reliable communication? Dose placing just a resistor at source can alleviate the problems? do I need impedance match for tracks?
Thanks,
