A gradient amplifier arrangement is described that comprises a gradient
amplifier power stage. The device may be employed to provide a current to
a gradient coil, as in a MRI system. The circuitry disclosed includes a
series coupling of a first bridge amplifier operating at a first voltage,
a second bridge amplifier operating at a second voltage, a third bridge
amplifier operating at a third voltage, and a gradient amplifier control
stage. The amplifiers may provide output voltages at different levels,
and may be switched at different times and frequencies to provide a range
of output voltage and current levels.