Compact PNP BJT-Based Temperature Sensor and Sub-1-V Bandgap Reference for SoC Applications in 4-nm FinFET

This article presents a dual-function circuit of a temperature sensor and a sub-1-V bandgap reference (BGR) implemented in the 4-nm FinFET CMOS process. The design, based on subthreshold MOS transistors and parasitic PNP bipolar junction transistor (BJT) devices, offers distinct advantages over existing PNP BJT-based sensors and sub-1-V BGRs. As a temperature sensor, it achieves the fastest conversion time of 7 mu s, while consuming a power of only 68.5 mu W, which results in the lowest energy consumption rate of 0.5 nJ per conversion. In addition, the sensor demonstrates a resolution of 0.46 C-degrees and a resolution figure-of-merit (FOM) of 0.106 nJ & sdot; K-2. It also functions as a low-cost, high-accuracy BGR capable of sub-1-V operation, producing a stable output of 450 mV within a compact 0.0061 mm(2) footprint, and featuring an accuracy of +/- 1.1%(+/- 3 sigma) along with an average temperature coefficient (TC) of 33 ppm/C-degrees. Moreover, by supporting both BGR and sensing modes, the design significantly reduces costs by incorporating dual functionalities within a single architecture.