A 1.2 V, 33 ppm/°C, 40 nW, regeneration based BGR circuit for nanowatt CMOS LSIs

Design of a CMOS Bandgap Reference Voltage Using the OP AMP in 180 nm Process

Abstract: This article proposes the implementation and design of a first-order CMOS Bandgap reference using an operational amplifier with negative feedback to improve the power supply rejection ratio (PSRR) and reduce the temperature coefficient (TC). The circuit is designed in 180 nm CMOS process technology and provides a reference output voltage of 1.2 V over an extended temperature range from −40 °C to 120 °C with a measured temperature coefficient of 54 ppm/°C. The BGR chip uses a 1.8 V supply.

1.2-V Supply, 100-nW, 1.09-V Bandgap and 0.7-V Supply, 52.5-nW, 0.55-V Subbandgap Reference Circuits for Nanowatt CMOS LSIs

Abstract: This paper presents bandgap reference (BGR) and sub-BGR circuits for nanowatt LSIs. The circuits consist of a nano-ampere current reference circuit, a bipolar transistor, and proportional-to-absolute-temperature (PTAT) voltage generators. The proposed circuits avoid the use of resistors and contain only MOSFETs and one bipolar transistor. Because the sub-BGR circuit divides the output voltage of the bipolar transistor without resistors, it can operate at a sub-1-V supply. The experimental results obtained in the 0.18-μm CMOS process demonstrated that the BGR circuit could generate a reference voltage of 1.09 V and the sub-BGR circuit could generate one of 0.548 V. The power dissipations of the BGR and sub-BGR circuits corresponded to 100 and 52.5 nW.

A Sub-1 ppm/°C Precision Bandgap Reference With Adjusted-Temperature-Curvature Compensation

Abstract: This paper presents a precision bandgap reference with an innovative adjusted-temperature-curvature compensation circuit that obtains a good temperature coefficient (TC) over a wide temperature range. The proposed compensation circuit for enhancing the voltage accuracy of the bandgap reference combines an addition circuit, subtraction circuit, and current mirror to achieve an adjusted piecewise linear temperature current over an entire temperature range. The proposed bandgap reference was designed and fabricated using a standard Taiwan Semiconductor Manufacturing Company (TSMC) $0.18~\mu \text{m}$ 1P6M CMOS technology. Measurements on eight samples indicated that the proposed bandgap reference achieved a TC that varies from 1.67 to 10.55 ppm/° from −40 °C to 140 °C with a supply voltage of 1.8 V. The measured 547 mV reference voltage achieved a precision line regulation that is less than 0.08%/V for supply voltages between 1.3 and 1.8 V. The proposed circuit dissipated $28~\mu \text{A}$ with a supply voltage of 1.8 V, and an active area of 0.0094 mm2. The circuit was designed to operate on a low supply voltage down to 1.3 V.

Matching performance of current mirrors with arbitrary parameter gradients through the active devices

Abstract: Effects of threshold gradients at any angle across a die and through active devices on the matching characteristics of current mirrors are discussed. Results show a major improvement but also an unreported limitation in performance of common-centroid layouts. A CAD tool that predicts performance of arbitrary layouts under arbitrary parameter gradients is introduced.