Academic Research Online Publisher
In this paper, the authors present the three-delay-stage low power differential ring oscillator used for RFID applications. To make oscillator frequency independent from temperature, two temperature compensation methods have been used. In the first method the NMOS diode-connected transistor is connected in series with PMOS load. As a result of complementary behavior of NMOS and PMOS, the temperature variation of the output voltage is reduced at each stage. In the second method in order to decrease the dependence of oscillator current to temperature, a diode-connected transistor has been used in the current supply.