1. A 0.5-V Supply, 36 nW Bandgap Reference With 42 ppm/°C Average Temperature Coefficient Within −40 °C to 120 °C.
- Author
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U, Chi-Wa, Zeng, Wen-Liang, Law, Man-Kay, Lam, Chi-Seng, and Martins, Rui Paulo
- Subjects
ON-chip charge pumps ,VOLTAGE dividers ,CAPACITOR switching ,VOLTAGE references ,SWITCHED capacitor circuits ,PHOTONIC band gap structures - Abstract
This paper presents a switched capacitor network (SCN)-based bandgap voltage reference (BGR) circuit designed and implemented in a 65nm standard CMOS process with a wide temperature range, high precision, low supply voltage and low power consumption for IoT device application. The proposed BGR employs a 2x charge pump with ripple optimization design to supply the ${V} _{\mathbf {EB}}$ generator, which can relax ${V} _{\mathbf {DD}}$ from 0.9V to 0.5V.A proportional to absolute temperature (PTAT) current source is proposed to bias the PNP BJT in order to reduce the nonlinearity of ${V} _{\mathbf {EB}}$. Moreover, a voltage divider SCN with low leakage consideration to form the complementary to absolute temperature (CTAT) voltage is designed to reduce the nonlinearity of its coefficient, while a series-parallel SCN with adjusted clock swing to form the PTAT voltage is designed to improve the line regulation of the BGR. The measurement result shows that the proposed BGR has a temperature coefficient (TC) of 42 ppm/°C at 0.5V supply within −40 °C to 120 °C. The line regulation is 3.2mV/V or 0.64%/V from 0.5V to 1V. Based on 6-chip test result, it shows a $3\sigma / \mu $ variation of 3.08% before trimming, while 0.36% after trimming. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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