A Sub-200nW All-in-One Bandgap Voltage and Current Reference Without Amplifiers

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 68; no. 1; pp. 121 - 125
• Main Authors: Huang, Wenbin, Liu, Lianxi, Zhu, Zhangming
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Bandgap voltage reference; Circuits; CMOS; Current measurement; Current mirrors; current reference; Electric potential; Energy gap; line sensitivity; Photonic band gap; Power consumption; Power management; Room temperature; Sensitivity; Sensitivity enhancement; temperature coefficient; Temperature measurement; Temperature sensors; Topology; Transistors; ultra-low-power; Voltage
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2020.3007195

This brief presents a low-power and high-precision bandgap voltage and current reference (BGVCR) in one simple circuit for battery-powered applications. All the amplifiers have been eliminated in the proposed circuit. The voltage reference is derived from the bandgap topology, and the current reference is obtained by summing a proportional-to-absolute-temperature (PTAT) current and a complementary-to-absolute-temperature (CTAT) current. Therefore, the temperature coefficient of the current reference can be optimized. Besides, a pseudo-cascode structure and a simple line sensitivity enhancement circuit are adopted to improve the current mirror accuracy and line sensitivity. The proposed circuit is fabricated in a 0.18-μm deep N-well CMOS process with an active area of 0.063 mm 2 . The measured VREF and IREF are 1.2 V and 51 nA, respectively. The VREF and IREF show measured average temperature coefficients of 32.7 ppm/°C and 89 ppm/°C at a temperature of -45 to 125°C and standard deviations of 0.17 % and 1.15 %, respectively. In the supply voltage range of 2 to 5 V, the line sensitivities of voltage and current are 0.058%/V and 1.76%/V, respectively. The minimum supply voltage is 2 V with a total power consumption of 192 nW at room temperature.