Abstract
This paper discusses a voltage-to-time converter (VTC) designed for use in a time-based analog-to-digital converter. The VTC considered in this work is based on a starved-inverter topology. Linearity, delay, and jitter of the VTC are analyzed to facilitate a physical understanding of the circuit performance. The design is experimentally verified in a 65-nm CMOS technology. Measurement results show that the VTC, operating with a 5-GHz clock, has an output delay range of \(\pm 25\,{\text{ ps }}\), 4.4 effective number of bits (ENOB), and output jitter of \(0.5\,\text{ ps }\) RMS while consuming 4 mW of power. The input effective resolution bandwidth (ERBW) of the VTC is measured to be 4.1 GHz, over which the ENOB remains above 3.5 bits. The same VTC, operating with a 7.5-GHz clock, consumes 9.7 mW of power from a 1.2-V supply, has ENOB of >3.8 bits, ERBW of >7 GHz, output jitter of \(0.4\,\text{ ps }\) RMS, and output delay range of \(\pm 25\,\text{ ps }\). The VTC achieves the widest input bandwidth of any VTC reported to date.
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Notes
In the case of a VTC, the headroom advantage applies not to voltage but to time—the VTC output can have double the delay range without modifying the timing constraints.
\(C_\mathrm{out}\) is assumed constant in this analysis and equal to its value when \(V_\mathrm{out}=\frac{1}{2}V_\mathrm{dd}\).
Flicker noise is ignored since the \(1/f\)-corner frequency is much smaller than the intended clock frequency.
[6] showed that this approximation slightly underestimates jitter.
Measurements were performed with a Keysight, formally Agilent, DSAX93204A scope.
References
A. Abidi, Phase noise and jitter in CMOS ring oscillators. IEEE J. Solid State Circuits 41(8), 1803–1816 (2006)
W. Bennett, Spectra of quantized signals. Bell Syst. Tech. J. 27(3), 446–472 (1948). http://www.alcatel-lucent.com/bstj/vol27-1948/articles/bstj27-3-446
J. Borremans, K. Vengattaramane, V. Giannini, B. Debaillie, W. Van Thillo, J. Craninckx, A 86 MHz-12 GHz digital-intensive PLL for software-defined radios, Using a 6 fJ/Step TDC in 40 nm digital CMOS. IEEE J. Solid State Circuits 45(10), 2116–2129 (2010)
R. Brodersen, Antiques from the innovations attic. IEEE Solid State Circuits Mag. 5(2), 78–79 (2013)
J. Bulzacchelli, D. Friedman, S. Naraghi, S. Rylov, A. Rylyakov, Z. Toprak-Deniz, Time-to-digital based analog-to-digital converter architecture (2011)
A. Homayoun, B. Razavi, Analysis of phase noise in phase/frequency detectors. IEEE Trans. Circuits Syst. I Regul. Pap. 60(3), 529–539 (2013)
A. Homayoun, B. Razavi, Relation between delay line phase noise and ring oscillator phase noise. IEEE J. Solid State Circuits 49(2), 384–391 (2014)
W. Kester, MT-001: Taking the Mystery out of the Infamous Formula, “SNR=6.02N + 1.76dB,” and Why You Should Care. [Online] (2012). Analog Devices, REV. 0, 10–03-2005. http://www.analog.com/static/imported-files/tutorials/MT-001
J. Kim, S. Cho, A time-based analog-to-digital converter using a multi-phase voltage controlled oscillator. In IEEE International Symposium on Circuits and Systems (Kos, Greece 2006), pp. 3934–3937
P. Kinget, J. Kuppambatti, B. Vigraham, C.W. Hsu, Scaling analog circuits. In IEEE European Solid-State Circuits Conference (Bucharest,Romania, 2013), p. 32
G. Li, Y. Tousi, A. Hassibi, E. Afshari, Delay-line-based analog-to-digital converters. IEEE Trans. Circuits Syst. II Exp. Br. 56(6), 464–468 (2009)
A. Macpherson, A time-based 5GS/s CMOS analog-to-digital converter. Ph.D. thesis, University of Calgary (2013)
A. Macpherson, J. Haslett, L. Belostotski, A 5GS/s 4-bit time-based single-channel CMOS ADC for radio astronomy. In IEEE Custom Integrated Circuits Conference (San Jose, 2013), pp. 1–4
A. Macpherson, K. Townsend, J. Haslett, A 5GS/s voltage-to-time converter in 90nm CMOS. In IEEE European Microwave Integrated Circuits Conference (Rome,Italy, 2009), pp. 254–257
Y.J. Min, A. Abdullah, H.K. Kim, S.W. Kim, A 5-bit 500-MS/s time-domain flash ADC in 0.18-\(\mu \)m CMOS. In International Symposium on Integrated Circuits (Singapore, 2011), pp. 336–339
S. Naraghi, M. Courcy, M. Flynn, A 9b 14\(\mu \)W 0.06mm\(^2\) PPM ADC in 90nm digital CMOS. In IEEE International Solid-State Circuits Conference (San Francisco, 2009), pp. 168–169
T. Oh, H. Venkatram, U. Moon, A time-based pipelined ADC using both voltage and time domain information. IEEE J. Solid-State Circuits 49(4), 961–971 (2014)
H. Pekau, A. Yousif, J. Haslett, A CMOS integrated linear voltage-to-pulse-delay-time converter for time based analog-to-digital converters. In IEEE International Symposium on Circuits and Systems (Kos,Greece, 2006), pp. 2373–2376
M. Park, M. Perrott, A VCO-based analog-to-digital converter with second-order sigma-delta noise shaping. In IEEE International Symposium on Circuits and Systems (Taipei, 2009), pp. 3130–3133
J. Rabaey, A. Chandrakasan, B. Nikolic, Digital Integrated Circuits—A Design Perspective, 2nd edn. (Prentice Hall, New Jersey, 2004)
W. Rao, P. Hanumolu, A deterministic background calibration technique for VCO-based ADCs. In Workshop on Advances in Analog Circuit and Design (Lisbon, 2014), pp. 1–4
S. Rao, B. Young, A. Elshazly, W. Yin, N. Sasidhar, P. Hanumolu, A 71dB SFDR open loop VCO-based ADC using 2-level PWM modulation. In IEEE Symposium on VLSI Circuits (2011), pp. 270–271
A. Samarah, A. Carusone, A digital phase-locked loop with calibrated coarse and stochastic fine TDC. IEEE J. Solid-State Circuits 48(8), 1829–1841 (2013)
Y.H. Seo, J.S. Kim, H.J. Park, J.Y. Sim, A 1.25 ps resolution 8b cyclic TDC in 0.13 \(\mu \)m CMOS. IEEE J. Solid-State Circuits 47(3), 736–743 (2012)
R. Staszewski, D. Leipold, C.M. Hung, P. Balsara, TDC-based frequency synthesizer for wireless applications. In IEEE Radio Frequency Integrated Circuits Symposium (Fort Worth, 2004), pp. 215–218
R. Staszewski, K. Muhammad, D. Leipold, C.M. Hung, Y.C. Ho, J. Wallberg, C. Fernando, K. Maggio, R. Staszewski, T. Jung, J. Koh, S. John, I.Y. Deng, V. Sarda, O. Moreira-Tamayo, V. Mayega, R. Katz, O. Friedman, O. Eliezer, E. de Obaldia, P. Balsara, All-digital TX frequency synthesizer and discrete-time receiver for Bluetooth radio in 130-nm CMOS. IEEE J. Solid State Circuits 39(12), 2278–2291 (2004)
R. Staszewski, J. Wallberg, S. Rezeq, C.M. Hung, O. Eliezer, S. Vemulapalli, C. Fernando, K. Maggio, R. Staszewski, N. Barton, M.C. Lee, P. Cruise, M. Entezari, K. Muhammad, D. Leipold, All-digital PLL and transmitter for mobile phones. IEEE J. Solid State Circuits 40(12), 2469–2482 (2005)
Y. Tousi, E. Afshari, A miniature 2 mW 4 bit 1.2 GS/s delay-line-based ADC in 65 nm CMOS. IEEE J Solid State Circuits 46(10), 2312–2325 (2011)
K. Townsend, A. Macpherson, J. Haslett, A fine-resolution time-to-digital converter for a 5GS/S ADC. In IEEE International Circuits and Systems Symposium (Paris, 2010), pp. 3024–3027
F. Trofimenkoff, J. Haslett, A. Nordquist, VFC with pulsewidth-to-period ratio proportional to input voltage. IEEE Trans. Instrum. Meas. IM–35(3), 237–244 (1986)
P. Wambacq, W. Sansen, Distortion Analysis of Analog Integrated Circuits (Kluwer Academic Publishers, Norwell, MA, USA, 1998)
T. Watanabe, T. Mizuno, Y. Makino, An all-digital analog-to-digital converter with 12-\(\mu \)V/LSB using moving-average filtering. IEEE J. Solid State Circuits 38(1), 120–125 (2003)
W. Wu, R. Staszewski, J. Long, A 56.4-to-63.4 GHz multi-rate all-digital fractional-N PLL for FMCW radar applications in 65 nm CMOS. IEEE J Solid State Circuits 49(5), 1081–1096 (2014)
L. Xu, K. Stadius, J. Ryynanen, An all-digital PLL frequency synthesizer with an improved phase digitization approach and an optimized frequency calibration technique. IEEE Trans Circuits Syst. I Regul. Pap. 59(11), 2481–2494 (2012)
Y. Xu, L. Belostotski, J. Haslett, A 65-nm CMOS 10-GS/s 4-bit background-calibrated noninterleaved flash ADC for radio astronomy. IEEE Trans. Very Large Scale Integr. (VLSI) Syst. 22(11), 2316–2325 (2014)
T. Yamaguchi, S. Komatsu, M. Abbas, K. Asada, N.N. Mai-Khanh, J. Tandon, A CMOS flash TDC with 0.84-1.3 ps resolution using standard cells. In IEEE Radio Frequency Integrated Circuits Symposium (Montreal, 2012), pp. 527–530
H. Yang, R. Sarpeshkar, A time-based energy-efficient analog-to-digital converter. IEEE J. Solid State Circuits 40(8), 1590–1601 (2005)
A. Yousif, J. Haslett, A fine resolution TDC architecture for next generation PET imaging. IEEE Trans. Nucl. Sci. 54(5), 1574–1582 (2007)
E. Zailer, T. Graham, L. Belostotski, R. Plume, R. Taylor, Analysis of the ADC resolution for radio astronomy applications. In IEEE International Symposium on Antenna Technology and Applied Electromagnetics (Victoria, Canada, 2014), pp. 1–4
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This work was supported by the University of Calgary, the Natural Sciences and Engineering Research Council of Canada, CMC Microsystems, Alberta Innovates Technology Futures, and NSERC’s Special Research Opportunity program.
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Macpherson, A.R., Belostotski, L. & Haslett, J.W. 65-nm CMOS Voltage-to-Time Converter for 5-GS/s Time-Based ADCs. Circuits Syst Signal Process 34, 3121–3145 (2015). https://doi.org/10.1007/s00034-015-0009-5
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DOI: https://doi.org/10.1007/s00034-015-0009-5