An ultra-low power energy-efficient microsystem for hydrogen gas sensing applications
- 299 Downloads
This paper presents a fully integrated power management and sensing microsystem that harvests solar energy from a micro-power photovoltaic module for autonomous operation of a miniaturized hydrogen sensor. In order to measure H2 concentration, conductance change of a miniaturized palladium nanowire sensor is measured and converted to a 13-bit digital value using a fully integrated sensor interface circuit. As these nanowires have temperature cross-sensitivity, temperature is also measured using an integrated temperature sensor for further calibration of the gas sensor. Measurement results are transmitted to the base station, using an external wireless data transceiver. A fully integrated solar energy harvester stores the harvested energy in a rechargeable NiMH microbattery. As the harvested solar energy varies considerably in different lighting conditions, the power consumption and performance of the sensor is reconfigured according to the harvested solar energy, to guarantee autonomous operation of the sensor. For this purpose, the proposed energy-efficient power management circuit dynamically reconfigures the operating frequency of digital circuits and the bias currents of analog circuits. The fully integrated power management and sensor interface circuits have been implemented in a 0.18 μm CMOS process with a core area of 0.25 mm2. This circuit operates with a low supply voltage in the 0.9–1.5 V range. When operating at its highest performance, the power management circuit features a low power consumption of less than 300 nW and the whole sensor consumes 14.1 μA.
KeywordsAnalog integrated circuits Solar energy harvesting Ultra-low power circuits Power management circuits Sensor interface circuits Wireless sensor networks
This work was supported by European project SiNAPS under contract number 257856. The authors would like to thank Dr. Vahid Majidzadeh for his support and helpful discussions about sensor interface circuit. The authors would also like to thank Prof. Fritz Falk and Dr. Jia Goubin from the Institute of Photonic Technology, Jena (IPHT-Jena) for providing miniaturized nanowire solar cells and Dr. Erik Puik for providing Palladium nanowire sensors.
- 3.Chen, G., Ghaed, H., Haque, R., Wieckowski, M., Yejoong K., Gyouho K., Fick, D., Daeyeon K., Mingoo S., Wise, K., Blaauw, D., & Sylvester, D. (2011). A cubic-millimeter energy-autonomous wireless intraocular pressure monitor. Proceedings of IEEE International Solid-State Circuits Conference, San Francisco, CA, USA, pp. 310–312.Google Scholar
- 5.Khosro Pour, N., Krummenacher, F., & Kayal, M. (2012). A miniaturized autonomous microsystem for hydrogen gas sensing applications. In Proceedings of IEEE 10th International New Circuits and Systems Conference, Montreal, Canada, pp. 201–204.Google Scholar
- 8.Varra V6HR Datasheet. Available online: http://www.varta-microbattery.com. Accessed on 10 March 2013.
- 10.Qiu, Y., Liempd, C. V., Veld, B. O. H., Blanken, P. G., & Hoof, C. V. (2011). 5 μW-to-10mW Input power range inductive boost converter for indoor photovoltaic energy harvesting with integrated maximum power point tracking algorithm. In Proceedings of IEEE International Solid-State Circuits Conference, San Francisco, USA, pp. 118–120.Google Scholar
- 11.InfinitePowerSolutions Co. Website. Available online: http://www.infinitepowersolutions.com. Accessed on 3 March 2012.
- 12.Toumaz TZ1053 Datasheet. Available online: http://www.toumaz.com/page.php?page=telran. Accessed on 13 March 2012.
- 13.Zarlink ZL70250 Datasheet. Available online: http://www.zarlink.com/zarlink. Accessed on 3 March 2013.
- 14.Lu, C., Raghunathan, V., & Roy, K. (2010). Maximum power point considerations in micro-scale solar energy harvesting systems. Proceedings of IEEE International Symposium on Circuits and Systems (ISCAS), Paris, France, pp. 273–276.Google Scholar
- 17.Premrudeepreechacham, S., & Patanapirom, N. (2003). Solar-array modeling and maximum power point tracking using neural networks”, IEEE Bologna Power Tech Conference, Bologna, Italy.Google Scholar
- 18.Pastre, M., Krummenacher, F., Robortella, R., Simon-Vermot, R., & Kayal, M. (2009). A fully integrated solar battery charger. In Proceedings of Joint IEEE North-East Workshop on Circuits and Systems and TAISA Conference, Toulouse, France, pp. 1–4.Google Scholar
- 23.Yanfei, C., et al. (2009). Split capacitor DAC mismatch calibration in successive approximation ADC. IEEE Custom Integrated Circuits Conference, 13–16, 279–282.Google Scholar