Alpha and Omega Semiconductor (cayman) Ltd.

Rhys Philbrick

Steven Patrick Laur

Nicholas Ian Archibald

An error amplifier circuit receives first and second input signals and provides an error amplifier output signal indicative of the difference between the first and second input signals. The error amplifier circuit implements a proportional-integrator-differentiator (PID) circuit having a differential input signal path and including a proportional amplifier circuit, an integrator amplifier circuit, and a differentiator amplifier circuit. The differentiator amplifier circuit receives an AC coupled input signal. The error amplifier circuit sums the output from the proportional amplifier circuit, the integrator amplifier circuit and the differentiator amplifier circuit to provide the error amplifier output signal where the error amplifier output signal is referenced to a first bias voltage.

Digitally programmable, fully differential error amplifier

A voltage-controlled oscillator (VCO) generates a clock signal in response to an input feedback signal by applying tuning to a control loop error signal related to the input feedback signal and generating the clock signal using a voltage ramp signal that is ground referenced. The VCO includes an input tuning circuit applying tuning to a difference signal to generate a tuned voltage signal, a comparator to compare the tuned voltage signal to the ground-based ramp signal, an one-shot circuit to generate an one-shot signal pulse in response to the ramp signal increasing to the tuned voltage signal. The one-shot signal pulse is the clock signal and is also used to reset the ramp signal. In some embodiments, the voltage-controlled oscillator of the present disclosure is incorporated in a current mode hysteretic modulator.

Voltage-controlled oscillator for current mode hysteretic modulator

A circuit for providing temperature compensation to a sense signal having a first temperature coefficient includes a temperature compensation circuit receiving a temperature sense signal indicative of a temperature associated with the sense signal where the temperature compensation circuit is digitally configurable by at least one digital signal to generate a compensating impedance signal having a second temperature coefficient. The compensating impedance signal provides an impedance value in response to the temperature sense signal. The compensating impedance signal is applied to modify the sense signal to provide a modified sense signal having substantially zero temperature coefficient over a first frequency range. The circuit further includes an amplifier circuit receiving the modified sense signal and generating an output signal indicative of the sense signal where the output signal has substantially zero temperature coefficient over the first frequency range.

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Los Gatos, CA, United States of America

Rhys Philbrick