Time-Domain ADCs for Digital-Intensive RF Receivers and Health-Care ICs for Nonelectrical Vital sign Monitoring

July 12, 2012
633 Mudd
Hosted by: Columbia Integrated Systems Laboratory
Speaker: Prof. Seongwhan Cho (KAIST)


In the first part of the talk, a time-domain ADC using voltage-controlled oscillators will be presented for a digital-intensive direct RF sampling receiver. Unlike conventional delta-sigma band-pass ADCs that require high speed analog circuits and passive components, the proposed architecture provides band-pass function by time-interleaving 1st-order noise-shaped VCO-based ADCs. The use of VCO-based ADC has the advantage that its resolution is determined by time-resolution rather than the voltage resolution, thus making it attractive for future low-voltage CMOS processes. In the second part of the talk, a technique to monitor pulse-wave velocity and respiration will be presented. By exploiting the change of electrical impedance in human body, we will show that such non-electrical vital signs from human body can be measured in an all electrical way.

Speaker Biography

SeongHwan Cho received the B.S. degree in electrical engineering from KAIST, Korea, in 1995, and the S.M. and Ph.D. degrees in EECS from MIT, Cambridge, MA, in 1997 and 2002, respectively. In 2002, he joined Engim, Inc., where he was involved in data converters and phased-locked loop (PLL) design for IEEE 802.11abg WLANs. Since November of 2004, he has been with KAIST in the department of EE, where he is now an associate professor. His research interests include mixed-signal and analog circuits for low power communication systems and bio/health-care devices. Prof. Cho was the co-recipient of the 2009 IEEE Transactions on Circuits and System Society Guillemin-Cauer Best Paper Award. Prof. Cho serves on the technical program committee on several IEEE conferences, including ISSCC, Symp. on VLSI and A-SSCC. He has served as an associate editor of IEEE Transactions on Circuits and Systems-I and a guest editor of JSSC.

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