Nanyang Technological University

Linfei Guo

Joseph Sylvester Chang

Tong Ge

Huiqiao He

A supply modulator is provided, having a first amplifier circuit configured to generate a first electrical signal, a second amplifier circuit configured to generate a second electrical signal, the first and second electrical signals being for driving an electrical load, and a control circuit electrically coupled to the first and second amplifier circuits wherein the control circuit is configured to generate a pulsed electrical signal and to supply an output control signal to the second amplifier circuit for controlling generation of the second electrical output signal, wherein the supply modulator is configured to operate in two modes of operation, for the first amplifier circuit to generate the first electrical signals in response to quiescent current of the first amplifier circuit, for the control circuit to generate a modulated electrical signal in accordance with a clock signal in one mode, and, for the second amplifier circuit to operate.

Supply modulator, power amplifier having the same, method for controlling the same, and method for controlling the power amplifier

An amplifier circuit for a parametric transducer, comprising: a signal processor for processing an input signal into first and second signals; and at least a pair of output stages arranged to respectively receive the first and second signals for generating amplified first and second signals respectively, which are provided to operate the parametric transducer. The input, first and second signals are arranged with a substantially similar frequency to cause a switching frequency of the amplifier circuit to be matched to a carrier frequency of the parametric transducer. A related audio device is also disclosed.

Amplifier circuit for a parametric transducer and a related audio device

A method () of generating a pulse width modulation (PWM) signal for an analog amplifier, the amplifier arranged to receive an amplifier input signal having a magnitude, is disclosed. The method comprises receiving () a modulator input signal, which is associated with the amplifier input signal; and using () the modulator input signal to modulate a carrier to produce the PWM signal, wherein the carrier's frequency varies in dependence on the magnitude of the amplifier input signal. A related pulse width modulator is also disclosed.

Method of generating a pulse width modulation (PWM) signal for an analog amplifier, and a related pulse width modulator

A dead time circuit () for a switching circuit is disclosed. The dead-time circuit comprises: an input () for receiving a switching signal of the switching circuit with at least one supply rail having a ground bounce signal; first and second outputs (); a first feedforward path () coupled to the first output and arranged to receive the switching signal; a second feedforward path () coupled to the second output and arranged to receive the switching signal; a first feedback path () forming a first feedback loop between the first output and the second feedforward path; and a second feedback path () forming a second feedback loop between the second output and the first feedforward path; wherein each of the first and second feedforward paths includes a respective first and second delay circuit (), each having a time delay greater than a predetermined time period of the ground bounce signal. A switching amplifier is also disclosed.

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Linfei Guo