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US 8,044,715 B2Granted
Method and system for increasing sampling frequency for switching amplifiers
AssigneeJM Electronics Ltd. LLC
InventorLarry Kirn
Life of this patent
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Abstract
The present invention is directed toward providing a system and method of reducing RF interference in switching amplifiers without degrading performance. In one embodiment, the sampling rate of coarse high voltage modulated pulsewidths are increased relative to the sampling rate of fine lower voltage modulated pulsewidths. This increase in the sampling rate of coarse high voltage modulated pulsewidths results in a reduction in EMI.
Claims23
A switching amplifier, comprising:
- a first set of switching devices configured to be coupled to a first voltage source and further configured to be coupled to a first output filter;
- a second set of switching devices configured to be coupled to a second voltage source and further configured to be coupled to a second output filter;
- a third set of switching devices configured to be coupled to a third voltage source;
- and
- a modulator including an input terminal configured to receive an input signal and further including respective output terminals coupled to individual ones of the first, second, and third sets of switching devices, wherein the modulator is further configured to control the first set of switching devices at a first sampling rate, to control the second set of switching devices at a second sampling rate, and to couple the first and second voltage sources to the first and second output filters, respectively, in accordance with the input signal, and wherein the first sampling rate is greater than the second sampling rate.
2 more elements
A switching amplifier, comprising:
- first, second, and third reference voltage sources;
- a first set of control switches, wherein each control switch of the first set is coupled to a respective one of the reference voltage sources and further coupled to a first output filter;
- a second set of control switches, wherein each control switch of the second set is coupled to a respective one of the reference voltage sources and further coupled to a second output filter;
- and
- a modulator including:
- an input terminal configured to receive an input signal;
- and
- a first plurality of output terminals coupled to respective ones of the first set of control switches;
- and
- a second plurality of output terminals coupled to respective ones of the second set of control switches, wherein the modulator is configured to generate a plurality of control signals for the first and second sets of control switches in response to the input signal, and wherein the plurality of control signals are configured to activate the control switches coupled to the first reference voltage source at a higher frequency than the control switches coupled to the second reference voltage source.
7 more elements
A method of operating a switching amplifier, the method comprising:
- receiving an input signal at an input terminal of the switching amplifier;
- applying a plurality of first pulsewidth-modulated voltage pulses to a first filter of the switching amplifier during a first period of time;
- and
- applying a plurality of second pulsewidth-modulated voltage pulses to a second filter of the switching amplifier during the first period of time, wherein a voltage of the first pulsewidth-modulated voltage pulses is greater than a voltage of second pulsewidth-modulated voltage pulses, and wherein the first pulsewidth-modulated voltage pulses are applied to the first filter at a higher frequency than the second pulsewidth-modulated voltage pulses are applied to the second filter.
1 more element
A system, comprising:
- a load;
- and
- a switching amplifier, including:
- a first set of switching devices configured to be coupled to a first voltage source and further configured to be coupled to a first output filter;
- a second set of switching devices configured to be coupled to a second voltage source and further configured to be coupled to second output filter;
- a third set of switching devices configured to be coupled to a third voltage source;
- and
- a modulator comprising:
- an input terminal configured to receive an input signal;
- and
- output terminals coupled to respective ones of the first, second, and third sets of switching devices;
- wherein the modulator is configured to control the first set of switching devices at a first sampling rate and further configured to control the second set of switching devices at a second sampling rate to thereby provide first and second voltages to the first and second output filters, respectively, in accordance with the input signal, and wherein the first sampling rate is greater than the second sampling rate.
9 more elements
Dependencies are inferred from the claim text.