Amplifier error current based on multiple integrators
AssigneeTexas Instruments Incorporated
InventorsAditya Sundar, Jasjot Singh Chadha
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Abstract
In some examples, an amplifier comprises a first integrator to receive a differential input signal, a second integrator coupled to the first integrator, a third integrator coupled to the second integrator, and a comparator to receive outputs of the second and third integrators, to compare each of the outputs to a reference signal that is below a power supply rail voltage supplied to the amplifier, and to produce an error current based on the comparison. The amplifier also comprises a feedback connection between the comparator and inputs to the second integrator. The feedback connection injects the inputs to the second integrator with a current that is determined at least in part by the error current.
Claims20
An amplifier, comprising:
- a first integrator to receive a differential input signal;
- a second integrator coupled to the first integrator;
- a third integrator coupled to the second integrator;
- a comparator to receive outputs of the second and third integrators, to compare each of the outputs to a reference signal that is below a power supply rail voltage supplied to the amplifier, and to produce an error current based on the comparison;
- and
- a feedback connection between the comparator and inputs to the second integrator, wherein the feedback connection injects the inputs to the second integrator with a current that is determined at least in part by the error current.
A class-D amplifier comprising:
- an integrator chain comprising a plurality of integrators, each of the integrators having multiple inputs and multiple outputs;
- a summer having inputs coupled to the outputs of a subset of the plurality of integrators;
- a first comparator having inputs coupled to the outputs of the subset of the plurality of integrators and to a first reference signal input;
- and
- a second comparator having inputs coupled to outputs of the summer and to a second reference signal input,
- wherein outputs of the first and second comparators couple to inputs of a first subset of the plurality of integrators.
A method comprising:
- operating a class-D amplifier with a loop filter having an integrator chain comprising a plurality of integrators;
- providing outputs of each of a subset of the plurality of integrators to a first comparator and to a summer, the first comparator receives a first reference signal;
- providing outputs of the summer to a second comparator, the second comparator receives a second reference signal;
- and
- injecting an error current into an input of a first of the subset of the plurality of integrators based on outputs of the first and second comparators.
Dependencies are inferred from the claim text.