A low-power fully-MOSFET voltage reference generator for 90nm CMOS technology

An integrated voltage reference generator, designed for being incorporated in standard 90-nm CMOS technology flash memories, is described in this paper. A fully MOSFET based approach, using also subthreshold operated devices, has been adopted in order to achieve low-voltage and low-power requirements and to overcome the difficulties of conventional band-gap reference circuits. The proposed circuit, based on current signals, internally generates two currents with opposite dependence on temperature. The two currents are added, thus canceling almost completely temperature dependence, and then linearly converted into the output voltage. For a temperature variation between -20degC and 90degC, the produced reference voltage shows a stability within 0.7%. The very low current consumption (1.3 muA), together with the possibility of operating at very low supply voltages (around 1V), make the circuit well suitable for applications in low-power low-voltage integrated circuits.