论文信息 - Subthreshold current-mode oscillator-based quantizer with 3-decade scalable sampling rate and pico-Ampere range resolution

Subthreshold current-mode oscillator-based quantizer with 3-decade scalable sampling rate and pico-Ampere range resolution

A current-mode oscillator-based analog-to-digital data converter (ADC) for bio-medical readout front-end systems is being presented. The core of this circuit is a current-controlled ring oscillator (CCO) whose oscillation frequency is proportional to the input current signal. To shape the quantization noise and improve the resolution, a CCO can be used as an integrator in ΔΣ configuration. Experimental results show that the proposed ADC can reach to 54 dB signal-to-noise ratio while the sampling frequency is 45.5 kHz and consuming 800 nW power (with an over-sampling ratio of 64). The sampling frequency of this ADC can be adjusted from 700 Hz to 540 kHz with a scalable power dissipation, corresponding to 17.5 pW/Hz.

Yusuf Leblebici | Armin Tajalli | Y. Leblebici | A. Tajalli

[1] A. Tajalli,et al. Ultra low power subthreshold MOS current mode logic circuits using a novel load device concept , 2007, ESSCIRC 2007 - 33rd European Solid-State Circuits Conference.

[2] Haiming Tang,et al. Time-referenced single-path multi-bit /spl Delta//spl Sigma/ ADC using a VCO-based quantizer , 2000 .

[3] A. Hajimiri,et al. Jitter and phase noise in ring oscillators , 1999, IEEE J. Solid State Circuits.

[4] T. Morie,et al. An architecture of Delta-Sigma A-to-D converters using a voltage controlled oscillator as a multi-bit quantizer , 1998, ISCAS '98. Proceedings of the 1998 IEEE International Symposium on Circuits and Systems (Cat. No.98CH36187).

[5] Michael H. Perrott,et al. A 12-Bit, 10-MHz Bandwidth, Continuous-Time ΣΔ ADC With a 5-Bit, 950-MS/s VCO-Based Quantizer , 2008, VLSIC 2008.

[6] Franco Maloberti,et al. A 60-dB dynamic-range CMOS sixth-order 2.4-Hz low-pass filter for medical applications , 2000 .

[7] John A. McNeill. Jitter in ring oscillators , 1997 .

[8] Terri S. Fiez,et al. using a VCO-Based Quantizer , 2000 .

[9] M.Z. Straayer,et al. A 12-Bit, 10-MHz Bandwidth, Continuous-Time $\Sigma\Delta$ ADC With a 5-Bit, 950-MS/s VCO-Based Quantizer , 2008, IEEE Journal of Solid-State Circuits.