Microchip Technology Inc.

James S Bartling

Neil F Deutscher

Jerry Hanauer

Jinhui Chen

Dennis P Lehman

Padmaraja Yedamale

A touch panel or screen has a serpentine transmission line fabricated on a substrate, e.g., printed circuit board, LCD, plasma or LED screen, etc., and has a constant impedance. Touches to the touch panel will cause changes of impedance of the transmission line at the locations of the touches. Time domain reflectometry (TDR) is used for determining the locations of the changes of impedance of the transmission line by accurately measuring the return pulse times at the source of a plurality of pulses, and then converting the return pulse times to X-Y coordinates of the touch panel or screen.

Touch sense determined by characterizing impedance changes in a transmission line

A touch panel or screen has a serpentine transmission line fabricated on a substrate, e.g., printed circuit board, LCD, plasma or LED screen, etc., and has a constant impedance. A touch to the touch panel will cause a change of impedance of the transmission line at the location of the touch. Time domain reflectometry (TDR) is used for determining the location of the change of impedance of the transmission line by accurately measuring the return pulse time at the source of the initial pulse, and then converting the return pulse time to X-Y coordinates of the touch panel or screen.

Touch sense using time domain reflectometry

An integrated circuit boost regulator design providing selection of either a low power on-chip power component boost regulator circuit or a high power off-chip power component boost regulator circuit using the same integrated circuit device.

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Chandler, AZ, United States of America

James S Bartling