1 ppm/°C bandgap with multipoint curvature-compensation technique for HVIC

A high-order curvature-compensated current mode bandgap reference (BGR) over a very wide temperature range is presented. High-order curvature correction for this reference is accomplished by the proposed multipoint corrected technique, which realises exponential curvature-compensation terms in lower and higher temperature ranges separately through simple structures. The compact multipoint curvature-compensation circuit cancels out the nonlinear terms of the BGR using subthreshold operated metal-oxide semiconductor field effect transistors, which subtract those currents that are proportional to the nonlinearity out of the reference voltage. As a result, a flattened and better effect of curvature compensation in a wide temperature range is realised. The circuit performance was verified experimentally. The measurements indicate that the proposed BGR can achieve a temperature coefficient as low as 1.01 ppm/degrees C over the temperature range of 160 degrees C (-40 to 120 degrees C).