Highly accurate switched capacitor DAC
US6924760B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2004 |
| Grant date | Aug 2, 2005 |
| Priority date | — |
| Expiry date | Feb 27, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/502
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In one set of embodiments the invention comprises a highly accurate, low-power, compact size DAC utilizing charge redistribution techniques. Two complementary conversions may be performed and added together to form a final DAC output voltage by performing charge redistribution a first time, and again a second time in a complementary fashion, followed by a summing of the two charge distributions, in effect canceling the odd order capacitor mismatch errors. By canceling all odd order mismatch errors the accuracy of the DAC may become a function of the square of the mismatch of the two capacitors, resulting in greatly increased accuracy. When performing the complementary conversions for multiple bits, the sequence in which each of the two capacitors is charged may be determined to minimize the even-order errors, especially second-order errors. The DEM technique may be applied, in conjunction with the complementary conversions, with less oversampling than required by current DEM implementations, resulting in even-order errors being substantially reduced in addition to all odd-order errors being eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.