Abstract: A power amplifier for receiving an input signal and providing a corresponding amplified output signal. One embodiment of the power amplifier includes a positive half circuit for supplying power to an amplifier during positive half waves of the output signal and a negative half circuit for supplying power to the amplifier during negative half waves of the output signal. Each half circuit has a main power supply, which is typically a switching regulator, and which supplies a first power signal to the amplifier. The slew rate of this first power signal is intentionally limited to control EMI emissions. Each half circuit also has a transient power supply which may be selectively engaged to provide a second power signal to the amplifier when the first power signal is insufficient to power the amplifier.

Abstract: A power amplifier for receiving an input signal and providing a corresponding amplified output signal. One embodiment of the power amplifier includes a positive half circuit for supplying power to an amplifier during positive half waves of the output signal and a negative half circuit for supplying power to the amplifier during negative half waves of the output signal. Each half circuit has a main power supply, which is typically a switching regulator, and which supplies a first power signal to the amplifier. The slew rate of this first power signal is intentionally limited to control EMI emissions. Each half circuit also has a transient power supply which may be selectively engaged to provide a second power signal to the amplifier when the first power signal is insufficient to power the amplifier.

Abstract: A composite bridge amplifier in which the power supply for the bridge amplifiers includes a time varying non-ground reference DC voltage supply dependant on the input signal. A low voltage power supply circuit uses the time varying non-ground reference DC voltage to produce a fixed DC voltage and includes a centering block which removes unbalanced DC voltages which might otherwise contaminate the time varying non-ground reference DC voltage, by providing balancing currents. This eliminates a costly transformer. Safety isolation is provided using an isolation amplifier with a transformer which has a parasitic capacitance. Improved common mode noise rejection is provided by configuring the isolation amplifier so that currents charging the parasitic capacitance with common mode noise voltage tend to cancel noise current in the secondary winding of the transformer.

Abstract: A self oscillating power converter uses two MOSFET transistors connected across first and second primary windings. Each MOSFET is controlled using a gate control circuit located in a feedback path. Each gate control circuit is driven by a gate drive winding which is transformer coupled to a primary winding and which is phased with the primary winding such that regenerative feedback causes accelerated sequential turn-on and turn-off of the associated MOSFET transistor. Each feedback path includes a capacitor for charging in response to the voltage generated across the gate drive winding to initiate turn-on of the MOSFET transistor and a resistor for discharging the capacitor to initiate turn-off of the MOSFET transistor. The power converter can be configured as a push-pull converter in either a common-drain or common-source configuration. The power converter can also be configured such that at least one MOSFET transistor is capacitively coupled to a primary winding.