Above question comes from a spam bot. See: http://electronics.stackexchange.com/questions/235276/digital-circuit-to-compare-two-voltages/235279 (their bot seem to suck up questions from electronics.stackexchange.com, insert their links and post to forums) If we see any more questions with Kynix-links, I'll just delete the new accounts. The @longkke user will be kept and banned for reference. I hope this will help other forums identifying Kynix as a SPAM cooperation.