A current calibration circuit for bandgap reference circuit

In this paper, a bandgap reference circuit is developed to improve the accuracy of the reference by calibrating the output current of the bandgap reference, which is composed of a high-order compensation bandgap reference, a current calibration module and a current detection module. The idea of the higher-order compensation circuit is to eliminate the higher-order term by generating T ln T , and the current calibration module is mainly adjusted by trimming technology. The 0.18um cmos process can generate an output reference voltage of 1.2V in with a temperature coefficient of2.25ppm/°C over a wide range of 190°C (-40°C⁓150°C) at a 3.3V supply voltage. The output current varies by 0.2% over the process angle range, the power supply rejection ratio(PSRR) is 96dB@0K, 83dB@0K, and the output quantization noise is -67.8dBV@1-40M, -66.4dBV@1-40M.