Abstract: In one form, a multi-mode converter includes first, second, third, and fourth transistors having respective control terminals and arranged in a four-switch buck-boost (FSBB) configuration for coupling to an inductor. The multi-mode converter also includes a first driver having an input for receiving a first switching signal and an output, a first charge pump having an output, a second driver having an input for receiving a second switching signal and an output, a second charge pump having an output, and a control circuit. The control circuit alternatively couples an output of the first driver or an output of the first charge pump to the control terminal of the first transistor, and the output of the second driver or the output of the second charge pump to the control terminal of the fourth transistor in response to a mode of operation of the multi-mode power converter.

Abstract: In one form, a multi-mode converter includes first, second, third, and fourth transistors having respective control terminals and arranged in a four-switch buck-boost (FSBB) configuration for coupling to an inductor. The multi-mode converter also includes a first driver having an input for receiving a first switching signal and an output, a first charge pump having an output, a second driver having an input for receiving a second switching signal and an output, a second charge pump having an output, and a control circuit. The control circuit alternatively couples an output of the first driver or an output of the first charge pump to the control terminal of the first transistor, and the output of the second driver or the output of the second charge pump to the control terminal of the fourth transistor in response to a mode of operation of the multi-mode power converter.

Abstract: Amplifier circuitry comprising a class-D amplifier for amplifying an audio input signal. The amplifier circuitry comprises sigma-delta modulation logic arranged to receive the audio input signal and to generate a modulated signal representative of the audio input signal, and an output stage arranged to generate an output signal for the amplifier circuitry. The amplifier circuitry further comprises finite impulse response, filter logic operably coupled between the modulation logic and the output stage, and having at least one zero in its transfer function arranged to substantially pass signal components within the modulated signal occurring at frequencies less than the at least one zero and to attenuate signal components within the modulated signal at frequencies greater than the at least one zero.

Abstract: Amplifier circuitry comprising a class-D amplifier for amplifying an audio input signal. The amplifier circuitry comprises sigma-delta modulation logic arranged to receive the audio input signal and to generate a modulated signal representative of the audio input signal, and an output stage arranged to generate an output signal for the amplifier circuitry. The amplifier circuitry further comprises finite impulse response, filter logic operably coupled between the modulation logic and the output stage, and having at least one zero in its transfer function arranged to substantially pass signal components within the modulated signal occurring at frequencies less than the at least one zero and to attenuate signal components within the modulated signal at frequencies greater than the at least one zero.

Abstract: A method of converting a plurality of input signals on first and second converters, such that the first and second converters are both used when the plurality of signals comprises two signals, characterised in that said method comprises: selecting more than two input signals; determining the type of each selected signal; combining any signals having the same type to form a combined signal; converting one type of signal with the first converter; converting a second type of signal with the second converter wherein the first or second type signals is a combined signal.

Abstract: A method of converting a plurality of input signals on first and second converters, such that the first and second converters are both used when the plurality of signals comprises two signals, characterised in that said method comprises: selecting more than two input signals; determining the type of each selected signal; combining any signals having the same type to form a combined signal; converting one type of signal with the first converter; converting a second type of signal with the second converter wherein the first or second type signals is a combined signal.

Abstract: A method of, and a converter for, converting an analogue input signal (X) to a digital output signal (Y) by incremental-delta conversion in which, at clock intervals, a non-uniform quantizer (7) produces digital quantizer signals, a digital-to-analogue converter (5) produces analogue quantizer signals that are a function of the digital quantizer signals, analogue difference signals (Q) are applied over a feedback loop to the quantizer (7) that are a function of the difference between the input signal (X) and the integral of the analogue quantizer signals since a reset signal, and the digital output signal (Y) is produced as a function of the sum of the digital quantizer signals since the reset signal.

Abstract: A method of, and a converter for, converting an analogue input signal (X) to a digital output signal (Y) by incremental-delta conversion in which, at clock intervals, a non-uniform quantizer (7) produces digital quantizer signals, a digital-to-analogue converter (5) produces analogue quantizer signals that are a function of the digital quantizer signals, analogue difference signals (Q) are applied over a feedback loop to the quantizer (7) that are a function of the difference between the input signal (X) and the integral of the analogue quantizer signals since a reset signal, and the digital output signal (Y) is produced as a function of the sum of the digital quantizer signals since the reset signal.