A sub-nW, self-biased voltage reference circuit is developed to provide bias signals for use in Internet-of-Things (IOT) applications, taking use of the sub-threshold region operation MOSFETs. Circuit is evaluated by simulation with 180nm SCL’s CMOS device parameters and 1.8 V voltage supply and from temperature -40˚C to 125˚C. Simulation shows that a temperature sensitivity of designed voltage reference is less than 100 ppm/°C. The size of the proposed design without IO pads is 30 µm × 30 µm and consumes power less than 50 nW.