Date: 18 Jan 2016
Venue: FSH, E12- G003
Speaker: Prof.SeongHwan Cho , Professor of Korea Advanced Institute of Science and Technology(KAIST)
Lecture 1: VCO-based Analog-to-Digital Converters for Highly-Digital RF Receivers
IIn this talk, time-based ADCs using voltage-controlled oscillators will be presented for digital-intensive RF receivers. First, an RF band-pass ADC for direct RF sampling receiver is introduced. Unlike conventional delta-sigma band-pass ADCs that require accurate DACs and high speed analog circuits, the proposed architecture provides band-pass function by time-interleaving 1st-order 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. Next, a direct conversion receiver employing VCO-based ADC with 2nd-order Sinc filter will be shown. The use of VCO-based ADC provides high sampling rate, wide dynamic range and inherent anti-alias filtering that eliminates the need for VGA and analog filters. Experimental results of RF band-pass and direct conversion receiver implemented in 65 and 90nm CMOS will be presented.
Lecture 2: All-electrical Sensors that Measure Heart rate, Pulse-wave Velocity and Respiration
We propose wire-free, all-electrical sensors that are capable of monitoring non-electrical vital signs such as pulse wave velocity (PWV) and respiration. The key techniques that we employ to obtain wire-free and all-electrical measurement are bio-impedance (BI) and analog-modulated body-channel communication (BCC). For PWV, time difference between ECG and BI signals are measured by placing an ECG sensor at the chest and a BI sensor at the wrist. ECG signal is sent to the BI sensor without any sampling via analog BCC to avoid sampling rate mismatch between the two sensors. For respiration, BI is measured at the abdomen. A prototype chip fabricated in 0.11um CMOS process consists of ECG/BI sensor and BCC transceiver. Measurement results show that heart rate and PWV are both within physiological range. The chip consumes 1.25mW at 1.2V supply while occupying 5mm x 2.5mm.
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 a professor. His research interests include analog and mixed-signal circuits for low power communication systems, bio/health-care devices and CMOS sensors. Prof. Cho was the co-recipient of the 2009 IEEE Transactions on Circuits and System Society Guillemin-Cauer Best Paper Award and 2012 ISSCC Takuo Sugano Award for Outstanding Far-East Paper. Prof. Cho has served on the Technical Program Committee on several IEEE conferences, including ISSCC, Symp. on VLSI and A-SSCC. He has served as associate editor of IEEE Trans. on Circuits and Systems-I and guest editor of JSSC. He also serves as a distinguished lecturer of IEEE Solid-State Circuits Society from 2015 to 2016. He has twice received Outstanding Lecturer Award from the department of EE and KAIST.
The lecture is open to the public
For enquiry: State Key Laboratory of Analog and Mixed-Signal VLSI
Tel. (853) 8822-8796 ; http://www.amsv.umac.mo