A 11.5nW CMOS bandgap voltage and current reference

For emerging high-tech products such as bioimplants, energy harvesters, and IoT sensing technologies, the semiconductor manufacturing industry may increasingly favor bandgap reference voltage sources due to their low cost, robustness, and compact size. In particular, in biocompatible electronic devices where ultra-low power consumption and miniaturized integrated circuits (ICs) are paramount, voltage and current references serve as fundamental building blocks of the IC system. This article presents an ultra-low power bandgap reference voltage and current circuit designed using an SMC 0.18um process model. The circuit combines a complementary-to-absolute-temperature (CTAT) voltage generated by bipolar transistors with a proportional-to-absolute-temperature (PTAT) voltage produced by a cascaded source-coupled pair structure to mitigate temperature dependence. Operating over an ambient temperature range of 0°C to 125°C, the circuit delivers a voltage reference of 1.235V and a current reference of 6.35nA, exhibiting a temperature coefficient of merely 93ppm/°C. It dissipates an exceptionally low power of just 11.5nW.