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US 2013/0293401 A1Published application
Sigma-delta digital-to-analog converter
AssigneeHoneywell International Inc.
InventorPaul M. Werking
Life of this patent
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Abstract
A sigma-delta digital-to-analog converter (SD DAC) exhibits undesirable distortion when implemented in an integrated circuit due to the non-linearity of polysilicon resistors used in the filtering stages of the SD DAC. By using resistors other than polysilicon for the output resistor of an SD DAC, distortion can be reduced or eliminated. Additionally or alternatively, by generating an error correction signal, the distortion can be corrected.
Claims20
A sigma-delta (SD) digital-to-analog converter (DAC) comprising:
- a translator stage comprising a sigma-delta modulator, wherein the translator stage is implemented on an integrated circuit;
- a filtering stage comprising an output resistor, wherein the output resistor is an approximately linear resistor, wherein at least a portion of the filtering stage is implemented on the integrated circuit.
A method comprising:
- performing sigma-delta digital-to-analog conversion on a digital input signal to generate an analog output signal;
- generating an error correction signal, wherein the error correction signal is based on a voltage coefficient of an output resistor;
- adding the error correction signal to the analog output signal to produce a corrected output signal.
(canceled)
A circuit comprising:
- a first path configured to perform sigma-delta digital-to-analog conversion on a digital input signal to generate an analog output signal;
- an error correction path configured to generate an error correction signal;
- an output resistor;
- a summing stage configured to subtract the error correction signal from the output signal to produce a corrected output signal across the output resistor.
1 more element
Dependencies are inferred from the claim text.