A start-up free 200nW bandgap voltage reference

A low power cross-coupled bandgap voltage reference is proposed in this paper. Based on the suggested structure, a 9.8 ppm/°C temperature coefficient bandgap voltage reference across -50°C to 150°C temperature range with 1.8-V supply voltage is achieved. For the help of the proposed cross coupled structure bandgap voltage reference, start-up circuit can be waived from which can save both area and power consumption for the bandgap circuit. Thus, The total power consumption is only 200 nW at room temperature with 1.8-V supply voltage. The proposed circuit can work at supply voltage varying from 1.4 V to 3.0 V while still enabling a wide temperature range bandgap voltage reference. All the simulation results were based on standard 0.18-μm CMOS process.