- Thu Mar 31, 2011 11:15 am
#124207
- Ideally I'd like to have valid, hard data on the actual components on the Sparkfun Pro Mini - the regulator, the caps, everything, which I don't recall seeing on the schematic where one would expect to find it. I presume the traces are usable at any voltage / current the components themselves support; if that's not the case it would be important to know.
- Sparkfun and about all "user grade" literature says the raw voltage input has a max of 12v. I accepted that at face value until I stumbled across what is supposed to be the datasheet for the regulator used by the Pro Mini in this thread:
viewtopic.php?f=7&t=13370&p=0&e=0
That datasheet (which does match the markings on my pro mini regulator) says the regulator will accept up to 16v.
- I want to run my Pro Mini from a standard "12v" car battery, which can actually put out near 14v on a fresh charge, but I'd *prefer* not to have to pre-regulate that "12v" just because it's a few over the user grade literature. Yet this datasheet is the *only* reference I've seen that does not say 12v, which makes me leery of trusting it as the only data point that lists a limit I prefer. (grin)
- But it could be the "user grade" literature really means the consumer variation of "12v", such as that put out by a car battery, rather than a literal limit of 12v as read by a multimeter. In that regard I don't trust even Sparkfun saying it's 12v means *rigidly* 12v, but "sort of" 12v.
- Be that as it may, I'm not interesting in zatching my Pro Mini. Anyone else would simply pre-regulate the voltage <12v literal and be done with it. I'm not wanting any more parts that I have to and consider it wasteful to toss in regulation if the device really can take a car battery's max output.
- If that datasheet is in fact accurate, then it also has all the information necessary to compute thermal safety limits, so if it will take 14v from a battery I can also make sure the regulator doesn't fail due to overheating.
- I do have a variable bench supply and I could run it up to 14v and check temps with the IR thermometer. I don't like that approach because it doesn't address long-term circuit stress - for instance if the regulator has a "max" voltage of 16v I can likely run it on 20v at low current as long as I don't mind severely reducing its usable life span. So knowing it "works" at 14v isn't sufficient. I need to know what the specs are on the parts and Pro Mini itself.
Thanks for your time...
- Sparkfun and about all "user grade" literature says the raw voltage input has a max of 12v. I accepted that at face value until I stumbled across what is supposed to be the datasheet for the regulator used by the Pro Mini in this thread:
viewtopic.php?f=7&t=13370&p=0&e=0
That datasheet (which does match the markings on my pro mini regulator) says the regulator will accept up to 16v.
- I want to run my Pro Mini from a standard "12v" car battery, which can actually put out near 14v on a fresh charge, but I'd *prefer* not to have to pre-regulate that "12v" just because it's a few over the user grade literature. Yet this datasheet is the *only* reference I've seen that does not say 12v, which makes me leery of trusting it as the only data point that lists a limit I prefer. (grin)
- But it could be the "user grade" literature really means the consumer variation of "12v", such as that put out by a car battery, rather than a literal limit of 12v as read by a multimeter. In that regard I don't trust even Sparkfun saying it's 12v means *rigidly* 12v, but "sort of" 12v.
- Be that as it may, I'm not interesting in zatching my Pro Mini. Anyone else would simply pre-regulate the voltage <12v literal and be done with it. I'm not wanting any more parts that I have to and consider it wasteful to toss in regulation if the device really can take a car battery's max output.
- If that datasheet is in fact accurate, then it also has all the information necessary to compute thermal safety limits, so if it will take 14v from a battery I can also make sure the regulator doesn't fail due to overheating.
- I do have a variable bench supply and I could run it up to 14v and check temps with the IR thermometer. I don't like that approach because it doesn't address long-term circuit stress - for instance if the regulator has a "max" voltage of 16v I can likely run it on 20v at low current as long as I don't mind severely reducing its usable life span. So knowing it "works" at 14v isn't sufficient. I need to know what the specs are on the parts and Pro Mini itself.
Thanks for your time...