Garry2009
Newbie level 4
Input protection...
Hello all...
I'm new to the world of microcontrollers, and recently got involved with using a Freescale MCU for a work project. I'll probably switch to TI for production units (printers), but here's my story: I found out the hard (and expensive) way that one cannot have any voltage of any kind on any input (I/O, DAC, whatever) while the card is powered down. TI tells me the same thing, and in fact, supposedly that's true for every MCU every made, for oldest to most current. Is this true?? Seems like most would (or should) probably some kind of internal clamping for this...no? Anyway, if it's needed, can someone recommend the best way to do this? TI says some kind of zener/resistor arrangement and something else I didn't catch. If this is as standard as TI is saying, then I would assume there's probably some "standard" way of dealing with floating inputs when the power is off...no?
Thanks for any help,
Garry
Hello all...
I'm new to the world of microcontrollers, and recently got involved with using a Freescale MCU for a work project. I'll probably switch to TI for production units (printers), but here's my story: I found out the hard (and expensive) way that one cannot have any voltage of any kind on any input (I/O, DAC, whatever) while the card is powered down. TI tells me the same thing, and in fact, supposedly that's true for every MCU every made, for oldest to most current. Is this true?? Seems like most would (or should) probably some kind of internal clamping for this...no? Anyway, if it's needed, can someone recommend the best way to do this? TI says some kind of zener/resistor arrangement and something else I didn't catch. If this is as standard as TI is saying, then I would assume there's probably some "standard" way of dealing with floating inputs when the power is off...no?
Thanks for any help,
Garry