Abstract: A system for controlling and measuring a power source switches between a first source and a second source in rapid succession to help maintain function of a load. In particular, a primary source may be replaced or augmented by an auxiliary source. Fast switching is achieved by delivering current to the output load through a nonlinear device. A record of conditions when the power sources switch modes is maintained in memory. The record is used to anticipate subsequent mode switching events.

Abstract: An apparatus for detecting off-track positioning of a disk read/write head seeking a selected data track on a disk having data tracks with embedded servo burst patterns recorded thereon. The apparatus comprises a compare and select component, a charge redistribution A/D converter circuit and an off-track controller. The compare and select component compares and selects from among voltage values corresponding to the servo bursts a pair best representing track centerline as a first servo signal and a second servo signal and determines which of the servo signals is greater. The charge redistribution analog-to-digital (A/D) converter circuit determines if the normalized track position exceeds a position threshold representing a percentage of the normalized track position distinguishing on-track from off-track position through the use of an internal binary-weighted, switched capacitor array DAC and a comparator.

Abstract: A switched-capacitor high pass filter is disclosed and in which a switched capacitor approximation of an inductor is inserted in the direct coefficient loop to prevent instability. The value of the inductor is selected to compensate for the filter termination phase error.