5 volt tolerant IO scheme using low-voltage devices

Systems and methods are disclosed for operating a core circuitry of an integrated circuit at a lower voltage than the coupled IO circuitry using a tolerant circuit. In one embodiment includes a voltage tolerant circuit comprising a voltage detect module adapted to detect when a voltage is sufficient to switch bias conditions without violating maximum transistor operating conditions and a comparator adapted to detect when a PAD voltage is greater than an IO power supply voltage.