Low-Power Subthreshold Voltage References for High-Temperature Applications

Advanced Internet-of-Things (IoT) devices are increasingly used in high-temperature environments, such as automotive, aerospace, defense, and industrial applications. High-temperature voltage references are crucial for these systems. This paper presents two topologies designed for high-temperature operation. The first topology minimizes design costs by using a replica branch to decouple leakage from the core, reducing its impact on the reference voltage. The second topology optimizes the operating temperature by employing one-stage amplifiers as buffers to handle junction leakage while maintaining body voltage. Both designs are fabricated in a 180 nm CMOS process. The first design supports operation up to $140~^{\circ }$ C with an average temperature coefficient (TC) of 70 ppm/°C, while the second design operates up to $170~^{\circ }$ C with a TC of 64 ppm/°C. The designs also exhibit line sensitivities of 0.46 %/V and 0.31 %/V, PSRRs of –37.8 dB and –38.3 dB at 100 Hz, and power consumption of 111 pW and 136.8 pW at room temperature, respectively.