Current drive mode digital-to-analog converter prefilter for reduced pulse width modulation control drive
AssigneeSkyworks Solutions, Inc.
InventorMark R. Peting
Life of this patent
Estimating the term…
Abstract
This disclosure relates to a feedback loop circuit for an electrical signal. The feedback loop comprises a first branch having a first switch and a second switch, the first branch to receive an input signal and provide a first signal based on the input signal to a first adder and to provide a second signal based on the input signal to a second adder; and a second branch having a feedback line coupled between a third switch and the first adder, the second branch to provide an output signal based on the first signal and the second signal.
Claims19
A feedback loop circuit for an electrical signal, the feedback loop comprising:
- an input;
- a first branch coupled to the input, the first branch having a first switch and a second switch, the first branch configured to receive an input signal from the input and to provide a first signal based on the input signal to a first adder and to provide a second signal based on the input signal to a second adder;
- and
- a second branch having a feedback line coupled between a third switch and the first adder, the second branch configured to provide an output signal based on the first signal and the second signal to a load.
A method for maintaining stability of a feedback loop circuit comprising:
- receiving an input signal;
- splitting the input signal into a first part and a second part;
- processing the first part with a digital filter having at least one filtering characteristic based on one or more filtering characteristics of a load;
- combining the first part with an output signal to produce a first summed signal;
- combining the second part with the first summed signal to produce a drive signal;
- passing the input signal through an equalizer to produce the second part;
- and
- passing the second part through the digital filter to produce the first part;
- and
- driving a pulse width modulator (PWM) using the drive signal.
A feedback loop for reducing noise in an output signal provided by a pulse width modulator (PWM), the feedback loop comprising:
- an input configured to receive an input signal;
- a plurality of supply rail connections selectively coupled to the PWM and configured to provide power to the PWM;
- an equalizer coupled to an adder, the equalizer configured to provide an equalized signal based on the input signal;
- a digital loop filter selectively coupled to a digital-to-analog converter (DAC), the digital loop filter configured to provide a filtered signal based on the equalized signal, the adder being further configured to provide a drive signal to the PWM based on the equalized signal, the filtered signal, and the output signal;
- and
- a controller configured to control the plurality of supply rail connections to selectively couple to the PWM based on an energy of the output signal.
Dependencies are inferred from the claim text.