Analog-to-digital converter with digital linearity correction
US5594612A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 24, 1994 |
| Grant date | Jan 14, 1997 |
| Priority date | — |
| Expiry date | Aug 24, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/50
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A analog calibration signal including at least one frequency component is generated by a very pure signal source, such as a digital oscillator and a digital-to-analog converter (DAC) that has been calibrated to be ultralinear. The analog calibration signal is converted by an analog-to-digital converter (ADC) to a digital signal. The digital signal is digitally compensated in accordance with compensation coefficients to produce a compensated digital signal. The compensated digital signal is digitally processed to isolate and measure distortion components, and the compensation coefficients are adjusted in response to the distortion components in order to reduce the distortion components. Feedback causes the distortion components to be minimized so that the compensation coefficients correct the nonlinearity in the analog-to-digital converter. Preferably the analog calibration signal is a two-tone signal, the digital signal is compensated by computing a polynomial, the compensation coefficients are coefficients of the polynomial, and the distortion components are intermodulation components. After calibration, the calibration coefficients can be adjusted to provide a specified non-linea…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.