[month] [year]

MSWCAS-2021 

Dr. Zia Abbas and his students published the following  papers at the 64th IEEE International Midwest Symposium on Circuits and Systems (MSWCAS-2021), Michigan from 8 – 11 August.

 

  • A 443pW Accumulation-Mode Gate-Leakage Based Bandgap Reference for IoT Applications –   Abhishek V Pullela, A  Ali, S Gurram and Zia Abbas.

Research work as described by the authors: The paper presents a sub-nW bandgap reference (BGR) that exploits the temperature variation of gate-leakage current in thin oxide devices operating in the accumulation region to generate the reference voltage. The incorporation of gate-leakage transistors scales down the power consumption of the BGR to pico-watt level without using any large physical resistors or sophisticated techniques, thereby making it suitable for IoT applications. The BGR is designed in TSMC 65nm technology and occupies an area of 0.009mm2. Post layout simulation results show nominal and worst-case accuracies of 23ppm/oC and 44ppm/oC respectively in the temperature range of −40oC to 100oC. Without any trimming, an inaccuracy (±3σ) of 3% is observed for the reference voltage, showing its resilience to process variations. It also exhibits a typical line sensitivity of 0.063%/V in a supply range of 1.5V-3.8V and a PSRR of -65dB at DC and 1.8V supply. The power consumption is observed to be 443pW at 1.5V supply and nominal temperature.  

 

  • A 0.85V Supply, High PSRR CMOS Voltage Reference without Resistor and Amplifier for Ultra-Low Power Applications – Ashutosh Pathy and Zia Abbas.

Research work as described by the authors: This paper presents an ultra-low power CMOS voltage reference (CVR) which is free of amplifier and resistor. A current generator circuit is used to generate a supply independent current to bias the active load in the temperature compensation circuit. The drain-source voltage of two critical MOSFETs is made equal in the current generator circuit by using a feedback arrangement to ensure a high PSRR of -75dB for the reference voltage. Temperature compensation is achieved by using the complementary to absolute temperature (CTAT) nature of gate-source of a MOSFET operating in the subthreshold region and proportional to absolute temperature (PTAT) nature of conventional composite pair architecture. The proposed CVR is designed in TSMC 180nm technology. The circuit works desirably for a supply range of 0.85V to 2.3V while generating a reference voltage of around 0.68V. Maximum temperature coefficient (TC) of 184 ppm/˚C and minimum TC of 69 ppm/˚C are noted for mismatch and process variations in the Monte-Carlo simulation for 1000 samples. The circuit consumes only 46nW of power, which makes it suitable for ultra-low power applications. 

 

The IEEE International Midwest Symposium on Circuits and Systems (MWSCAS) is the oldest, and now the flagship, Circuits and Systems symposium. The 64th meeting of the MWSCAS was hosted by Michigan State University, in East Lansing, Michigan, USA, from 8 – 11 August. The MWSCAS 2021 had pivoted to a fully virtual symposium to add a sense of certainty supported and managed by the convenient CONFlux virtual platform. It included oral and poster sessions, a student paper contest, keynote addresses, regular and special sessions, and tutorials presented by world experts in a wide range of circuits and systems topics. The 2021 Symposium theme was artificial intelligence (AI) and autonomous circuits and systems, and hopes to bring forward solutions to consequences of the COVID-19, from detection, testing to predictions. 

 

More details at: https://www.mwscas2021.org/