Ati Technologies Inc.

Jim M Seto

Raymond Chau

Roger P Colbeck

Simon C Leung

A phase locked loop is comprised of a phase-frequency detector for providing to a charge pump up and down pulse signals having pulse widths proportional to phase differences between a pair of signals applied thereto, apparatus for introducing a relative phase difference between a first clock signal and a second signal to provide the pair of signals, the second signal being synchronized with an output signal of the loop, apparatus for providing a third up or down signal to the charge pump offsetting the effect of the introduced phase difference, and apparatus for obtaining a loop control voltage from the charge pump.

Phase offset cancellation technique for reducing low frequency jitters

A voltage to current converter is formed of a first current steering mirror which includes first binary weighted current mirror transistors and receives an input voltage signal and converts it to an output current. The converter also is formed of a second current mirror which generates a selectable output current, the second current mirror being formed of second binary weighted current mirror transistors. The output currents of the first current steering mirror and second current mirror are added and the sum is provided to the control input of a current controlled oscillator which can be used in a phase locked loop.

Growing community of inventors

North York, Canada

Jim M Seto