A new compact temperature-compensated CMOS current reference

This paper describes a new circuit integrated on silicon, which generates temperature-independent bias currents. Such a circuit is firstly employed to obtain a current reference with first-order temperature compensation, then it is modified to obtain second-order temperature compensation. The operation principle of the new circuits is described and the relationships between design and technology process parameters are derived. These circuits have been designed by a 0.35 mu m BiCMOS technology process and the thermal drift of the reference current has been evaluated by computer simulations. They show good thermal performance and in particular, the new second-order temperature-compensated current reference has a mean temperature drift of only 28 ppm/degrees C in the temperature range between -30 degrees C and 100 degrees C.