I'm feeling like an idiot here. I've found this great little IC that will do the job I want but I can't seem to figure out what the max voltage is that can be supplied for sensing.
The IC runs on 5Vdc and the version I want to use is the 30A size.
I'm trying to sense when a 100W RF amplifier is working. The amplifier runs on 13.8Vdc and has a standby current of about 0.5A but when it's working it jumps to 21-23A.
Being fairly new to the whole thing I was hoping someone could point out where on the data sheet it says I'm good-to-go or DON'T DO IT MAN you're going to be making magic blue smoke.
Looking at the datasheet makes me think there is no friggin way a tiny IC can handle this much juice running through it without it melting. Am I missing something? It looks like they say it needs to be wired in series with the amplifier.
ACS714-DataSheet
Best Answer
Yes, you have it correct, the device should be wired in series with the amplifier. The pins 1,2 and 3,4 are isolated from the hall sensor circuitry. They are simply a conduction path with a nominal resistance of 1.2mΩ, so even at 30A the maximum dissipation is only 30^2 * 0.0012 = 1.08W
Hall sensing is an isolated technique, this IC just has the current p[ath fixed rather than needing to position it over a current carrying trace as with other hall ICs
This page on Allegros site explains: