The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 20, 2001
Filed:
Oct. 29, 1998
Paul Fowers, Tucson, AZ (US);
Burr-Brown Corporation, Tucson, AZ (US);
Abstract
A self-calibrating digital-to-analog converter includes a delta-sigma modulator (,) receiving a digital input signal, an output producing a stream of digital pulses the density of which represents a value of the digital input signal, and an intermediate digital input port coupled to a digital summing element which is also coupled to an output of an integrator within the delta-sigma modulator. A 1-bit DAC converts the stream of digital pulses to an analog signal that is filtered to produce an analog output voltage. A 1-bit DAC converts the analog output signal to a digital feedback signal, and a successive approximation circuit produces a digital offset correction signal from the digital feedback signal and loads it into an offset register. An output port of the offset register is coupled to the intermediate digital input port to provide self-calibration of an offset error without skewing an input range of the digital input signal. The filter circuit includes an operational amplifier and switching circuitry operative to isolate the analog output voltage from both the inverting input and the output of the operational amplifier during the self-calibration operation of the self-calibrating digital-to-analog converter.