A 180\u2009nm Self-biased Bandgap Reference with High PSRR Enhancement

Yue Shi,Jianwen Cao,Shilei Li,Zekun Zhou,Weiwei Ling

doi:10.1186/s11671-020-03333-w

Abstract

In this paper, an improved self-biased bandgap reference (BGR) with high power supply rejection ratio (PSRR) is presented. An operational amplifier constructing feedback loop is multiplexed with the generation of positive temperature coefficient (TC) voltage for lower power consumption, where an offset voltage is adopted to achieve proportional to absolute temperature (PTAT) voltage. With the temperature-independent reference generation, two feedback loops are realized at the same time for PSRR enhancement, which form a local negative feedback loop (LNFL) and a global self-biased loop (GSBL). The proposed BGR is implemented in a 180 nm BCD technology, whose results show that the generated reference voltage is 2.506 V, and the TC is 25 ppm/°C in the temperature range of −55 to 125 °C. The line sensitivity (LS) is 0.08 ‰/V. Without any filter capacitor, the PSRR is 76 dB at low frequencies, over 46 dB up to 1 MHz.

Highlights

Voltage reference is one of the core modules in electronic systems, which is widely used in medical electronics, power managements, wireless environmental sensors, and communication circuits
When the supply voltage increases above the minimum required supply voltage of proposed bandgap reference (BGR), the core operational amplifier starts to work, and the reference voltage is quickly stabilized at the desired value
The start-up current drops about to zero with a desired reference voltage, while the proposed self-bias current source (SBCS) taking the place of current supply with the global self-biased loop (GSBL)

Summary

Introduction

Voltage reference is one of the core modules in electronic systems, which is widely used in medical electronics, power managements, wireless environmental sensors, and communication circuits. With the improvement of technology, the area of chip continues to shrink, and the anti-interference ability continues to increase, and the requirements for structural optimization and noise immunity of voltage reference are increasing dramatically, especially in nanoscale applications [1]. Conventional bandgap reference (BGR) circuits require additional circuit blocks to provide bias current for the entire circuit, which greatly increases the circuit area and power consumption. The generated bias current is greatly affected by temperature, which affects the temperature coefficient (TC) of the reference voltage. Conventional solutions to improve PSRR are at the cost of chip area and power consumption [5], such as additional amplifiers, long channel transistors, cascode structures [6], additional gain stage [7], and so on. Body bias and negative feedback techniques were utilized in [10] for high PSRR

Methods

Results

Conclusion