Second order digital filter requiring only one sigma delta modulator
US6232900A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1999 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Apr 26, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H17/0411
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A 2.sup.nd order digital filter requiring only one sigma delta modulator is created by implementing (1) a 2.sup.nd order feedforward term created by the cascade of two 1.sup.st order elements; (2) a 2.sup.nd order feedback term created by the cascade of two 1.sup.st order elements; and (3) another 2.sup.nd order feedback term created by the cascade of two more 1.sup.st order elements to eliminate the need for another sigma delta modulator to provide a 2.sup.nd order filter. Thus, for the mere `cost` of additional feedback loops, which are small in comparison with the size and complexity of another sigma delta modulator, a second sigma delta modulator is not necessary to implement a 2.sup.nd order digital filter in accordance with the principles with the present invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.