Chen, C., & Zhang, H. (n.d.). a 0.6-V, 69-dB subthreshold sigma–delta modulator *Project supported by the National Natural Science Foundation of China (No. 61704143), the Natural Science Foundation of Fujian Province (No. 2018J01566), the Young and Middle-Aged Teacher Education Research Project of Fujian Province (No. JAT170428), and the High-Level Talent Project of Xiamen University of Technology (No. YKJ17019R).. Journal of semiconductors, 39, . http://access.bl.uk/ark:/81055/vdc_100086725368.0x000028