Second-Order Curvature Compensation Bandgap Reference
Guizhi Liu · Journal of Electron Devices · 2005
a first-order curvature compensation bandgap voltage reference has a temperature coefficient above 30×10 -6/℃.It couldn’t achieve the requirement of some high-precision system. So high-order curvature compensation technique is been added to first-order bandgap circuit.When a MOSFET is working at sub-threshold area in standard CMOS process,its drain current can be expressed with exponential relationship.So we can impose this exponential relationship to cancel the second-order item of the V_ be(T),Also the simulation result that employs CSMC 0.6 μm two metal two poly CMOS process is given.The output voltage is about 1.234V,and the temperature coefficient of this bandgap is about 10ppm/C between -50℃ to 120℃。