A Low-Noise Low-Power Second-Order Compensated Cmos Bandgap Reference

The design of a low-noise and low-power second-order bandgap reference voltage source using a linear combination of two base-emitter voltages with only one scaling factor is treated. The design takes into account the temperature dependency of the resistors and the finite current gain of BJT�s. The circuit is integrated in a CMOS process. The output voltage is approximately 140 mV with an average temperature dependency of 22.5 ppm/K in the range of 0�C to 120�C. Its equivalent output noise voltage is 57.6nV/vHz. The total current consumption is about 115 �A from a 2V voltage-supply.