کنفرانس مهندسی برق ایران

صفحه اصلی / سی و سومین کنفرانس بین المللی مهندسی برق

A Design Methodology for Submicron Low-Voltage Bandgap Voltage Reference

نویسندگان :

Mehdi Samavati¹ Samad Sheikhaei² Mohsen Jalali³

1- دانشگاه تهران 2- دانشگاه تهران 3- دانشگاه تهران

کلمات کلیدی :

bandgap reference،mismatch،reference voltage accuracy،optimization،systematic circuit design

چکیده :

The accuracy of a submicron low-voltage bandgap voltage reference (BGR) is significantly influenced by the precision of the current density ratio of the PN junctions, which is closely related to the mismatch between current source transistors as well as their short channel effects. Although increasing the current or the area of the current source transistors can help reduce this mismatch, it comes with trade-offs: increasing the current rises power consumption, while increasing the area results in a larger chip area. Additionally, for a specific current, increasing the area can cause the transistors to operate in a region with a weaker inversion level, which increases channel length modulation and ultimately reduces the reference voltage accuracy. To address these challenges, this paper presents a method for systematically determining the minimum dimensions and current of the current source transistors required to achieve the desired accuracy for the reference voltage. Based on the presented method, two BGRs are designed: one with high precision and the other with low power consumption, using a standard 40 nm low-power CMOS technology to provide a 250 mV reference voltage. Operating with a 1.1 V supply voltage, the two BGRs consume about 10 µW and 2.5 µW of power, respectively. Monte Carlo simulations indicate 3σ accuracies of 0.3% and 10%, respectively.