Analysis and design of sub-μW bandgap references in nano-meter CMOS

Analysis and design of nano-watt (nW) bandgap references (BGR) in nano-meter (nm) CMOS are presented. Three different BGR topologies are studied and design trade-offs are discussed. Based on the analysis results, a BGR is fabricated in a TSMC 90 nm CMOS process. A special feature is that it can generate proportional to absolute temperature (PTAT) and complementary to absolute temperature (CTAT) current individually which enables more possibility of system co-design. Measurements show temperature coefficient and line sensitivity without trimming are 47.1 ppm/°C and 0.8 %/V respectively. The power consumption of the BGR core with a 1.2 V supply is 315 nW at room temperature. The core area is 0.026 mm².