@article{liu_vichienchom_clements_demarco_hughes_mcgucken_humayun_juan_weiland_greenberg_2000, title={A neuro-stimulus chip with telemetry unit for retinal prosthetic device}, volume={35}, ISSN={["1558-173X"]}, DOI={10.1109/4.871327}, abstractNote={In this retinal prosthesis project, a rehabilitative device is designed to replace the functionality of defective photoreceptors in patients suffering from retinitis pigmentosa (RP) and age-related macular degeneration (AMD). The device consists of an extraocular and an intraocular unit. The implantable component receives power and a data signal via a telemetric inductive link between the two units. The extraocular unit includes a video camera and video processing board, a telemetry protocol encoder chip, and an RF amplifier and primary coil. The intraocular unit consists of a secondary coil, a rectifier and regulator, a retinal chip with a telemetry protocol decoder, a stimulus signal generator, and an electrode array. This paper focuses on the design, fabrication, and testing of a microchip which serves as the telemetry protocol decoder and stimulus signal generator. It is fabricated by MOSIS with 1.2-mm CMOS technology and was demonstrated to provide the desired biphasic current stimulus pulses for an array of 100 retinal electrodes at video frame rates.}, number={10}, journal={IEEE JOURNAL OF SOLID-STATE CIRCUITS}, author={Liu, WT and Vichienchom, K and Clements, M and DeMarco, SC and Hughes, C and McGucken, E and Humayun, MS and Juan, E and Weiland, JD and Greenberg, R}, year={2000}, month={Oct}, pages={1487–1497} }
 @misc{hall_clements_liu_bilbro_2000, title={Integrated circuits having cooperative ring oscillator clock circuits therein to minimize clock skew}, volume={6,104,253}, number={2000 Aug. 15}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Hall, L. C. and Clements, S. M. and Liu, W.-T. and Bilbro, G. L.}, year={2000} }
 @article{moyer_clements_liu_schaffer_cavin_1997, title={The delay vernier pattern generation technique}, volume={32}, ISSN={["0018-9200"]}, DOI={10.1109/4.563677}, abstractNote={The authors describe a new technique for generating an arbitrary digital data stream with very fine timing resolution. Note that this timing resolution specifies the output edge placement precision, not the bit rate. The resolution is determined by the difference between two propagation delays rather than by an absolute delay. Because this difference can be made very small, the circuit, called the delay vernier generator, can achieve unprecedented timing resolution in a particular circuit technology. Also, this very precise timing is obtained without requiring an extremely high speed clock. The generator architecture includes delay-locked loop calibration mechanisms to compensate for process and temperature variations. A prototype chip was fabricated in a 1.2-/spl mu/m CMOS technology, and measurements confirmed that resolutions as fine as 100 ps can be achieved reliably.}, number={4}, journal={IEEE JOURNAL OF SOLID-STATE CIRCUITS}, author={Moyer, GC and Clements, M and Liu, WT and Schaffer, T and Cavin, RK}, year={1997}, month={Apr}, pages={551–562} }