Design and analysis of high performance current reference generators for low-power CMOS data converters

Based on a highly accurate current divider using switched-current technique without the need of well-matched components, a current reference generator (CRG) circuit is developed to generate and hold the weighed currents used in the data converters. This paper also presents a methodology for designin g high-performance CMOS CRG circuits for low-power applications and their p erformance analysis for estimating the accuracy, speed, and power consumpti on. To demonstrate the design procedure and performance analysis, several d esign examples are given. The simulation results show that, for a 6-bit CRG circuit, its calibration time and holding time are 27 and 242 mu s, respec tively, and for a 8-bit CRG circuit, they are 48 and 236 mu s, respectively . The circuit consumes 1.8 mW and achieves better than 10-bit accuracy, whe re a MOSIS SCNA20 2-mu m process and a 3.3-V supply voltage are employed, T hus, the developed CRG circuit is well suited for low-power/low-voltage and moderate resolution data converters.