A resistor-free temperature-compensated CMOS current reference

This paper presents a resistor-free temperature compensated CMOS current reference designed in a standard 0.18 μm CMOS process. The temperature compensation scheme is achieved by combining a PTC (Positive Temperature Coefficient) current generator circuit with a NTC (Negative Temperature Coefficient) current generator circuit. The proposed design is shown to be less sensitive to process and temperature variations and well suited for integration into other circuits as an accurate and stable current source. Simulation results for the proposed current reference show a temperature coefficient of 170 ppm/°C over a temperature range of 20 °C to 120 °C and an output current variation of 3% over a power supply range of 2 V to 3 V.