D2audio Corporation

Zetex Plc

Brian E Attwood

Jack B Andersen

Systems and methods for controlling amplification of a pair of pulse width modulated signals. In one embodiment, a system comprises an audio amplifier which is configured to receive a pulse code modulated (PCM) input signal, convert this signal to a pulse width modulated (PWM) signal in a controller, and amplify the PWM signal in an output stage. The controller separates the PWM signal into a high-side signal and a low-side signal. The controller incorporates digitally programmable delays into the processing paths for each of the high-side and low-side signals. The high-side and low-side signals are separately provided to the output stage. The separate high-side and low-side signals can be used to individually control (e.g., turn off) the high-side and low-side transistors. Circuitry is included to generate a short low-side pulse when both transistors are turned off in order to drain the gate charge from the high-side transistor.

Integrated PULSHI mode with shutdown

An electric circuit comprising a transformer having first and second magnetically coupled inductors, a first switch which is connected to the first inductor, a second switch which is connected to the second inductor so as to be turned on and off by the second inductor; and a timing circuit for connection to the first switch for turning the first switch on and off. The second inductor is magnetically coupled to the first inductor such that flux reversal in the first inductor which occurs as the first switch is turned off will induce flux reversal in the second inductor which will thereby turn on the second switch. The circuit includes a damping element arranged to damp the operation of the second switch.

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Temecula, CA, United States of America

Brian E Attwood