Power amplifier esp. gradient amplifier of magnetic resonance imaging tomograph

摘要

The power amplifier has at least two end stages connected in series at the output. Each of the output stages has a power breaking circuit to generate a respective output stage voltage by pulse width modulation according to a respective clock. An output voltage of the power amplifier is generated as the sum of the end stage voltages. The output stage clocks of the different output stages are offset relative to each other. This increases the effective switching frequency of the output voltage. Preferably the amplifier has an odd number of output stages e.g. five.