US 6,661,285 B1 · Power efficient capacitive load driving device

Abstract

A device and method for driving a capacitive load that has a more power efficient design. The power efficient capacitive load driving device can be used to drive one or more acoustic transducers of a parametric audio system with low distortion and a flat frequency response. The capacitive load driving device includes a current source, a plurality of switches interconnected in an “H-bridge” configuration coupled to an output of the current source, and a controller. The plurality of interconnected switches is coupleable to at least one capacitive load. By driving the capacitive load with at least one controlled switched drive signal, the capacitive load driving device delivers (recovers) energy to (from) the capacitive load in an optimal manner, thereby generating a desired output voltage waveform across the capacitive load with increased power efficiency.

Claims21

Dependent claims

A device for driving a capacitive load, comprising:

at least one current source having an output;
a plurality of switches coupleable to the load and configured to be controlled for switchingly connecting the load between the current source output and a reference potential to place the load in at least a first orientation to charge the load positively and a second orientation to discharge the load or charge the load negatively;
and
a controller configured to receive a first input representing a predetermined waveform, and control the switches based on at least the first input to place the load in at least the first or second orientation to cause a voltage differential across the load to correspond to the predetermined waveform.

1 more element

A method of driving a capacitive load, comprising the steps of:

providing at least one current source having an output and a plurality of switches for switchingly connecting the load between the current source output and a reference potential to place the load in at least a first orientation to charge the load positively and a second orientation to discharge the load or charge the load negatively;
receiving a first input representing a predetermined waveform by a controller;
and
controlling the switches based on at least the first input to place the load in at least the first or second orientation by the controller to cause a voltage differential across the load to correspond to the predetermined waveform.

1 more element

Dependencies are inferred from the claim text.

Power efficient capacitive load driving device

Life of this patent

Power efficient capacitive load driving device

Life of this patent

Abstract

Claims21