Research
My PhD thesis involved the design of highly digital radios and ADCs for the ultra-wideband project. My masters thesis involved designing an RF transceiver for the µAMPS project. The µAMPS project explores issues in design and implementation of wireless sensor networks.
My overall research interests are in low power, energy efficient circuit and system design. As systems move from being performance limited to energy limited, it is necessary to maximize the energy efficiency of all system components. The goal of my research is to develop techniques that allow for an order-of-magnitude increase in battery lifetimes of mobile devices.
Journal Publications
D. C. Daly, P. P. Mercier, M. Bhardwaj, A. L. Stone, Z. N. Aldworth, T. L. Daniel, J. Voldman, J. G. Hildebrand, A. P. Chandrakasan, "A Pulsed UWB Receiver SoC for Insect
Motion Control," IEEE Journal of Solid-State Circuits, vol. 45, no. 1, pp. 153-166, January 2010.
[ paper PDF ]
A. P. Chandrakasan, D. C. Daly, D. F. Finchelstein, J. Kwong, Y. K. Ramadass, M. E. Sinangil, V. Sze, N. Verma, "Technologies for Ultra Dynamic Voltage Scaling," Proceedings of the IEEE, vol. 98, no. 2, pp. 191-214, February 2010.
[ paper PDF ]
D. C. Daly and A. P. Chandrakasan, "A 6-bit, 0.2V to 0.9V Highly Digital Flash ADC with Comparator Redundancy," IEEE Journal of Solid-State Circuits, vol. 44, no. 11, pp. 3030-3038, November 2009.
[ paper PDF ]
P. P. Mercier, D. C. Daly, A. P. Chandrakasan, "An Energy-Efficient All-Digital UWB Transmitter Employing Dual
Capacitively-Coupled Pulse-Shaping Drivers," IEEE Journal of Solid-State Circuits, vol. 44, no. 6, pp. 1679-1688, June 2009.
[ paper PDF ].
A. P. Chandrakasan, F. S. Lee, D. D. Wentzloff, V. Sze, B. P. Ginsburg, P. P. Mercier, D. C. Daly, R. Blazquez,
"Low-Power Impulse UWB Architectures and Circuits," Proceedings of the IEEE, vol. 97, no. 2, pp. 332-352,
February 2009.
[ paper PDF ]
A. P. Chandrakasan, N. Verma, D. C. Daly, "Ultra Low-Power Electronics for Biomedical Applications," Annual Review of Biomedical Engineering, vol. 10, August 2008.
[ paper website ]
D. C. Daly, A. P. Chandrakasan, "An Energy Efficient OOK Transceiver for Wireless Sensor Networks," IEEE Journal of Solid-State Circuits, vol. 42, no. 5, pp. 1003-1011, May 2007.
[ paper PDF ]
B. H. Calhoun, D. C. Daly, N. Verma, D. Finchelstein, D. D.
Wentzloff,
A. Wang, S.-H. Cho, A. P. Chandrakasan, "Design Considerations for Ultra-low Energy Wireless Microsensor Nodes," IEEE Transactions on Computers, June 2005.
[ paper PDF ]
Conference Publications
P. P. Mercier, M. Bhardwaj, D. C. Daly, A. P. Chandrakasan, "A 0.55V 16Mb/s 1.6mW Non-Coherent IR-UWB Digital Baseband with +-1ns Synchronization Accuracy," IEEE International Solid-State Circuits Conference (ISSCC), pp. 252-253, February 2009.
[ paper PDF |
slides PDF ]
D. C. Daly, P. P. Mercier, M. Bhardwaj, A. L. Stone, J. Voldman, R. B. Levine, J. G. Hildebrand, A. P. Chandrakasan, "A Pulsed UWB Receiver SoC for Insect Motion Control," IEEE International Solid-State Circuits Conference (ISSCC), pp. 200-201, February 2009.
[ paper PDF ]
P. P. Mercier, D. C. Daly, A. P. Chandrakasan, "Energy Efficient Pulsed-UWB for Miniaturized Flying Vehicles," Presented at the CMOS Emerging Technologies Workshop, February 2009.
A. P. Chandrakasan, D. C. Daly, J. Kwong, Y. R. Ramadass, "Next Generation Micro-power Systems," IEEE Symposium on VLSI Circuits, pp. 2-5, June 2008.
P. P. Mercier, D. C. Daly, A. P. Chandrakasan, "A 19pJ/pulse UWB Transmitter with Dual
Capacitively-Coupled Digital Power Amplifiers," IEEE Radio Frequency Integrated Circuits (RFIC) Symposium, pp. 47-50, June 2008.
[ paper PDF |
slides PDF ]
P. P. Mercier, D. C. Daly, M. Bhardwaj, D. D. Wentzloff, F. S. Lee, A. P. Chandrakasan, "Ultra-Low-Power UWB for Sensor Network Applications," IEEE International Symposium on Circuits and Systems (ISCAS), pp. 2562-2565, May 2008.
[ paper PDF |
slides PDF ]
D. C. Daly, M. Bhardwaj, F. S. Lee, P. P. Mercier, D. D. Wenztloff, J. Voldman, A. P. Chandrakasan, "Energy Efficient Pulsed-UWB Transceiver for Insect Flight Control," Government Microcircuit Applications & Critical Technology Conferece (GOMACTech), pp. 401-404, March 2008.
D. C. Daly, A. P. Chandrakasan, "A 6-bit, 0.2V to 0.9V Highly Digital Flash ADC with Comparator Redundancy," IEEE International Solid-State Circuits Conference (ISSCC), pp. 554-555, February 2008.
[ paper PDF ]
D. D. Wentzloff, F. S. Lee, D. C. Daly, M. Bhardwaj, P. P. Mercier, A. P. Chandrakasan, "Energy Efficient Pulsed-UWB CMOS Circuits and Systems", IEEE International Conference on Ultra-Wideband (ICUWB), September 2007
[ paper PDF |
slides PDF ]
D. C. Daly and A. P. Chandrakasan, "An Energy Efficient OOK
Transceiver for Wireless Sensor Networks," IEEE Radio Frequency
Integrated Circuits Symposium, pp. 279-282, June 2006.
Awarded the Student Paper Prize, 3rd place.
[ paper PDF |
slides PDF ]
A. Chandrakasan, N. Verma, J. Kwong, D. Daly, N. Ickes, D.
Finchelstein, B. Calhoun, "Micropower Wireless Sensors," Presented at NSTI
Nanotech, pp. 459-462, vol 3, May 7-11, 2006.
[ EE
Times article summarizing the paper ]
B. Bougard, D. Daly, A. P. Chandrakasan, F. Catthoor, W.
Dehaene,
"Energy Efficiency of the IEEE 802.15.4 Standard in Dense Wireless
Microsensor
Networks: Modeling
and Improvement Perspectives," Presented at the Design, Automation and Test in
Europe (DATE) Conference,
March 2005.
[ paper PDF |
slides PDF ]
Included in the book, The
Most Influential Papers of 10 Years DATE
D. Daly and A. Chan Carusone,
"A Sigma-Delta Based Open-Loop Modulator,"
Presented at the 2003 IEEE International Symposium on Circuits and Systems,
Bangkok, Thailand, May 2003.
[ paper PDF ]
Theses
Denis Daly, "Highly Digital ADCs and Ultra-Wideband Wireless Circuits for Energy Constrained Applications," Ph.D. Thesis, Electrical Engineering, Massachusetts Institute of Technology, June 2009.
Denis Daly, "An Energy Efficient Transceiver for Wireless Sensor Networks," S.M. Thesis, Electrical Engineering, Massachusetts Institute of Technology, May 2005.
Denis Daly, "Direct GSMK Generation Using Sigma-Delta Modulation," B.A.Sc. Thesis, Division of Engineering Science, University of Toronto, April 2003.
Other Presentations
D. Daly, D. Finchelstein, N. Ickes, N. Verma, A. P. Chandrakasan, "An Ultra Low Power Wireless Microsensor Node," 2006 DAC/ISSCC Student Design Contest, 3rd place winner.
D. Daly, N. Ickes, B. Calhoun, D. Finchelstein, N. Verma, A. Wang, D. Wentzloff, A. P. Chandrakasan, "Power-Aware Sensor Signal Processing," poster at DARPA Power Aware Computing and Communications Meeting, Portland, OR, June 22-23, 2004.
D. Finchelstein, N. Verma, B. Calhoun, D. Daly, N. Ickes, A. Wang, D. Wentzloff, A. P. Chandrakasan, "Power-Aware Sensor Signal Processing," poster at DARPA Power Aware Computing and Communications Meeting, January 27-28, 2004.
Chip Gallery
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A Pulsed UWB Receiver SoC for Insect Flight Control Co-designed with Patrick Mercier and Manish Bhardwaj April 2008 A highly integrated, 3-to-5 GHz non-coherent pulsed UWB RX SoC is designed for an insect flight control system. The SoC includes an integrated 4-channel PWM stimulator. The highly duty cycled RX requires 0.5-to-1.4 nJ/bit. A multistage tuned inverter-based RF front end and differential signal chain allow for robust, low energy operation. The receiver achives a maximum sensitivity of -76dBm at a data rate of 16Mb/s (10^(-3) BER). |
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A 19pJ/pulse UWB Transmitter with Dual Capacitively-Coupled Digital Power Amplifiers Co-designed with Patrick Mercier April 2007 A pulsed ultra-wideband transmitter operating in the 3-to-5GHz band is designed in 90nm CMOS. The all-digital architecture generates pulses by capacitively combining two paths which have in-phase RF signals, yet have counter-phase common-mode components that are canceled. This technique results in FCC-compliant pulse generation without requiring the use of any off-chip filters. The transmitter operates at a maximum data rate of 15.6Mbps, requires a core area of 0.07mm2, and achieves an energy efficiency of 19pJ/pulse. |
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A 6-bit, 0.2V to 0.9V Highly Digital Flash ADC with Comparator Redundancy October 2006 A 6-bit highly digital flash ADC is implemented in a 0.18um CMOS process. The ADC operates in the subthreshold regime down to 200mV and employs comparator redundancy to improve linearity. Common-mode rejection is implemented digitally via an IIR filter. The ADC's minimum FOM is at a supply of 0.4V, where it achieves a FOM of 125fJ/conversion-step and a ENOB of 5.05 at 400kSPS. |
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An Energy Efficient OOK Transceiver for Wireless Sensor Networks May 2005 A 1 Mbps 916.5 MHz OOK transceiver for wireless sensor networks has been designed in a 0.18-µm CMOS process. The RX has an envelope detection based architecture with a highly scalable RF front end. The RX power consumption scales from 0.5 mW to 2.6 mW, with an associated sensitivity of -37 dBm to -65 dBm at a BER of 10^(-3). The TX consumes 3.8 mW to 9.1 mW with output power from -11.4 dBm to -2.2 dBm. The RX achieves a startup time of 2.5 µs, allowing for efficient duty cycling. |
System Gallery
An Ultra Low Power Wireless Micro-Sensor Node
December 2005
This custom wireless sensor node PCB integrates a custom chipset (ADC, DSP, radio) and demonstrates a typical application of acuoustic sampling, classification, and wireless notification.