a simple adc question...

ferkar · Joined: 14 Jul 2007 Posts: 38

could anyone tell me what is the maxium adc input should be?
may i convert 100v signal by using Vref+ and Vref-?

thanks..

Guest · Posted: Thu Dec 13, 2007 4:01 am

Absolutely not.
Look at the chip's data sheet. 'Electrical characteristics'. Very first page. 'Voltage on any pin, with respect to Vss'. -0.3v to Vdd+0.3v.
You cannot use the ADC, outside the supply range of the chip. You can sense and read a 100v signal, by using a potential divider, but if this can deliver more than a tiny current level, consider something safer.

Best Wishes

rnielsen · Joined: 23 Sep 2003 Posts: 852 Location: Utah

If you are working with voltages of that level you absolutely, positively, without fail, must KNOW what you are doing or you risk not only damaging components but yourself!!! Learn what is needed before you attempt to tinker with this. I've been hit with 350VDC while tinkering and it HURTS! Luckily it was not capable of high current. Shocked

Just be careful and study up first.

Ronald

Eugeneo · Joined: 30 Aug 2005 Posts: 155 Location: Calgary, AB

Becareful if you build a divider at these voltages. 1/4 watt is used up very quickly. P=I^2R