Analog-Digital converter using delta sigma modulation digital filtering, and gain-scaling
US5757299A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1995 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Sep 26, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/43
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An analog-digital converter comprises a .DELTA. .SIGMA. modulator, a digital filter, a high-pass filter and a multiplier which are connected in series. Analog input is converted into serial-bit strings by the .DELTA. .SIGMA. modulator, for which gain `1/A` is set. The digital filter extracts low-frequency components, corresponding to the analog input, from the serial-bit strings, so the low-frequency components are converted into parallel-bit digital data. The high-pass filter removes DC offset component from output of the digital filter; and then, output thereof is multiplied by scaling gain `A` by the multiplier so that digital output is produced. The .DELTA. .SIGMA. modulator comprises at least three switched-capacitor integrators and a one-bit quantizer, which are connected in series, as well as a one-sample delay circuit. One-bit output, produced by the one-bit quantizer, is delayed by the one-sample delay circuit, whose output is delivered to each switched-capacitor integrator. Each switched-capacitor integrator is configured using a CMOS differential amplifier which is configured by a CMOS operational amplifier and at least one amplitude-limiting circuit. The amplitude-limit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.