Cirrus Logic Inc.

Angus Black

John L Melanson

Eric Jerome King

Axel Thomsen

Thomas H Hoff

Ross Crawford Morgan

Hemant Shukla

Malcolm Blyth

Neil Whyte

Andy Brewster

This application relates to methods and apparatus for driving a transducer with switching drivers. A switching driver has first and second supply node for receiving supply voltages and includes an output bridge stage, a capacitor and a network of switches. The network of switches is operable in different switch states to provide different switching voltages to the output bridge stage. A controller is configured to control the switch state of the network of switches and a duty cycle of output switches of the output bridge stage based on an input signal to generate an output signal for driving the transducer.

Driver circuitry and operation

A device comprising: a data interface comprising: a data input for receiving a data signal; a clock input for receiving a clock signal for clocking the data signal; and a timing input for receiving a first timing signal having a first frequency; and a timing signal generator configured to generate, based on the first timing signal and the data signal, a second timing signal having a second frequency, the first frequency being a integer multiple of the second frequency, a phase of the second timing signal being aligned with an event in the data signal.

Timing signal synchronisation

This application describes an amplifier circuit () with a forward signal path with a class-D output stage () for generating a driving signal (Sout) based on a digital input signal (Sin). The amplifier has a first feedback path for providing a first digital feedback signal (Sfb) based on the driving signal and a second feedback path for providing a second digital feedback signal (Sfb) from a digital part of the forward signal path. The digital input signal (Sin) is combined with a selected feedback signal (Sfbs). The amplifier circuit is selectively operable in a first mode, in which the first feedback signal is used as the selected feedback signal, and in a second mode, in which the second feedback signal is used as the selected feedback signal. A calibration module () is operable to calibrate the first feedback path to reduce any DC offset when the amplifier circuit is operating in the second mode.

Amplifiers

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Edinburgh, United Kingdom

Angus Black