A low-power temperature-compensated CMOS relaxation oscillator
- 549 Downloads
A relaxation oscillator with integrated voltage and current reference generation circuitry is presented in this paper for on-chip clock signal generation in low-power applications. Designed and simulated in 0.11 μm CMOS technology, the oscillator provides a clock signal at the frequency of 20 kHz with a temperature coefficient of 314 ppm/ °C over a range from −20 to 80 °C. The oscillator’s output signal frequency has a standard deviation of 7.9 % under the influence of device mismatches. It operates with a supply voltage of 1.2 V and has a dynamic power consumption of 4.9 μW at room temperature. An integrated voltage and current reference generator was developed to provide two reference voltages at 484.6 and 663.5 mV with simulated temperature coefficients of 7.5 and 16 ppm/ °C over a range from −20 to 80 °C respectively, as well as a reference current of 26.84 nA with a temperature coefficient of 166 ppm/ °C over the same temperature range.
KeywordsRelaxation oscillator Temperature compensation Process variation Low-power analog design Reference voltage generation Reference current generation
This work was supported in part by the NSF Grant ECCS-1349692. The authors thank Chun-hsiang Chang from Northeastern University for valuable discussions.
- 1.Bala, F., Nandy, T. (2005) Programmable high frequency RC oscillator. Proceedings of IEEE 18th International Conference VLSI Design, 511–515.Google Scholar
- 2.Barnett, R., Liu, J. (2006) A 0.8 V 1.52 MHz MSVC relaxation oscillator with inverted mirror feedback reference for UHF RFID, Proceedings IEEE Custom Integrated Circuits Conference (CICC), 769–772.Google Scholar
- 5.Chang, C.-W., Lo, T.-Y., Chen, C.-M., Wu, K.-H., Hung, C.-C. (2007) A low-power CMOS voltage reference circuit based on subthreshold operation. Proceedings of IEEE International Symposium on Circuits and Systems, 3844–3847.Google Scholar
- 6.De Vita, G., Marraccini, F., and Iannaccone, G. (2007) Low-voltage low-power CMOS oscillator with low temperature and process sensitivity, Proceedings of IEEE International Symposium (ISCAS), 2152–2155.Google Scholar
- 8.Geraedts, P. F. J., Van Tuijl, E., Klumperink, E. A. M., Wienk, G. J. M., and Nauta. (2008) A 90 μW 12 MHz relaxation oscillator with a −162 dB FOM, IEEE International Solid-State Circuits Conference (ISSCC) Dig. Tech. Papers, 318–618.Google Scholar
- 12.Osaki, Y., Hirose, T., Kuroki, N. and Numa, M. (2010) Nano-ampere CMOS current reference with little temperature dependence using small offset voltage. Proceedings of IEEE International Midwest Symposium on Circuits and Systems (MWSCAS), 668–671.Google Scholar