A resistorless CMOS bandgap reference with low temperature coefficient and high PSRR

A novel bandgap reference (BGR) with low temperature and supply voltage sensitivity without any resistor, which is compatible with standard CMOS process, is presented in this article. The proposed BGR utilises a differential amplifier with an offset voltage proportional to absolute temperature to compensate the temperature drift of emitter-base voltage. Besides, a self-biased current source with feedback is used to provide the bias current of the BGR core for reducing current mirror errors dependent on supply voltage and temperature further. Verification results of the proposed BGR implemented with 0.35 mu m CMOS process demonstrate that a temperature coefficient of 10.2 ppm/degrees C is realised with temperature ranging from -40 degrees C to 140 degrees C, and a power supply rejection ratio of 58 dB is achieved with a maximum supply current of 27 mu A. The active area of the presented BGR is 160 x 140 mu m(2).