Raytheon Company

Siemens Medical Solutions Usa, Inc.

Frederick Alan Williams

David A Petersen

De Dzwo Hsu

Robert A Hewitt

Wendy L Liu

For transformerless switching regulators, a current-mode controlled boost converter operates based on current sensing through a switch to ground, allowing use of common controllers. To avoid reverse current from a cascaded charge pump, the input of the charge pump is blocked by a diode from passing through the switch to ground and is itself separately switched to ground.

Transformerless switching regulator with controllable boost factor

A high resolution digital phase detector adapted to receive a threshold value and a sequence of digital samples of a substantially linear portion of an analog video signal. A first output signal is provided when a digital sample is detected as having crossed the threshold value. An interpolation is done between the value of the digital sample to first cross the threshold value and the immediately preceding digital sample on the opposite side of the threshold value. In such manner, the time of the crossing within the sample interval is resolved to a subpixel level. A second output signal represents a fractional phase error between the actual crossing and a desired crossing point within the sample interval. The first and second signals are added in a phase locked loop to adjust the output of a voltage controlled oscillator to be synchronized to the incoming analog video signal in both integer and subpixel phase.

Growing community of inventors

Bellevue, WA, United States of America

Frederick Alan Williams