A low-power low-noise CMOS voltage reference with improved PSR for wearable sensor systems

This paper describes a novel sub-threshold voltage reference generator suitable for very low power and very low voltage wearable systems. Indeed, the circuit, designed and extensively simulated in a standard 0.18-μm CMOS technology, generates a 51.3-mV output voltage with a nominal supply voltage of 0.5 V and consumes as low as 185 nW. Design optimisation and a first order temperature compensation allow achieving a temperature coefficient of 25.4 ppm/ C in the temperature range from −40 to 125° C. The proposed architecture optimizes the output noise performance by minimizing the current mirrors flicker and thermal noise contributions which, in conventional schemes, severely affect the output node. In addition, the same circuital arrangement allows obtaining high power supply rejection (PSR). The simulated root mean square output noise is 1.6 μV in the frequency range from 0.1 Hz to 10 Hz, while the PSR is −76 dB at 100 Hz, a remarkable value.

[1]  Ralf Brederlow,et al.  An Ultra Low Power Bandgap Operational at Supply From 0.75 V , 2012, IEEE Journal of Solid-State Circuits.

[2]  Giuseppe Iannaccone,et al.  A 2.6 nW, 0.45 V Temperature-Compensated Subthreshold CMOS Voltage Reference , 2011, IEEE Journal of Solid-State Circuits.

[3]  Franco Maloberti,et al.  A 0.4-V Supply Curvature-Corrected Reference Generator With 84.5-ppm/°C Average Temperature Coefficient Within −40 °C to 130 °C , 2017, IEEE Transactions on Circuits and Systems II: Express Briefs.

[4]  K. Sakui,et al.  A CMOS bandgap reference circuit with sub-1-V operation , 1999 .

[5]  David D. Wentzloff,et al.  5.4 A 32nW bandgap reference voltage operational from 0.5V supply for ultra-low power systems , 2015, 2015 IEEE International Solid-State Circuits Conference - (ISSCC) Digest of Technical Papers.

[6]  Y. Amemiya,et al.  A 300 nW, 15 ppm/$^{\circ}$C, 20 ppm/V CMOS Voltage Reference Circuit Consisting of Subthreshold MOSFETs , 2009, IEEE Journal of Solid-State Circuits.

[7]  G. Palumbo,et al.  A low-voltage low-power voltage reference based on subthreshold MOSFETs , 2003, IEEE J. Solid State Circuits.

[8]  Michael R. Neuman,et al.  Wearable sensors : fundamentals, implementation and applications , 2014 .

[9]  Gaetano Palumbo,et al.  A detailed analysis of power-supply noise attenuation in bandgap voltage references , 2003 .

[10]  Giuseppe de Vita,et al.  A Sub-1-V, 10 ppm/ $^{\circ}$C, Nanopower Voltage Reference Generator , 2007, IEEE Journal of Solid-State Circuits.