A 3.0 <i>μ</i> Vrms, 2.4 ppm/°C BGR With Feedback Coefficient Enhancement and Bowl-Shaped Curvature Compensation

Abstract

This paper demonstrates a low-noise, offset and temperature coefficient (TC) bandgap reference for the portable biopotential signal monitoring system. The proposed feedback coefficient enhancement technique suppresses the low-frequency noise and offset voltage. Besides, the bowl-shaped curvature compensation is applied in the BGR to obtain a decent TC. The proposed bandgap reference was designed and fabricated by the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.18 ~\mu \text{m}$ </tex-math></inline-formula> deep N-well CMOS technology with an active area of 0.088 mm2. Experimental results show that this BGR outputs 0.6 V reference voltage under 1.2 V supply voltage while consuming <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$60 ~\mu \text{W}$ </tex-math></inline-formula> power. The measured integrated noise from 0.1 to 10 Hz is about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.0 ~\mu \text{V}$ </tex-math></inline-formula> (rms). In addition, the average TC of the BGR is 2.4 ppm /°C from −45 °C to 125 °C after trimming.