Multiplexed sigma-delta A/D converter
US5150120A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 3, 1991 |
| Grant date | Sep 22, 1992 |
| Priority date | — |
| Expiry date | Jan 3, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/454
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A sigma-delta analog-to-digital converter employs multiplexed single-loop modulators in parallel and respectively phased time-divided clocks. The parallel modulators have the effect of producing digital output at a high sampling frequency that is a multiple of the phased switching frequencies applied to the modulator circuits. In one preferred embodiment, four second-order sigma-delta modulators are driven in clocked phased sequence and combined by a multiplexor circuit. Another embodiment employs second-order modulators using RC integrators. A further embodiment replaces the multiplexor with an adder when in-phase modulator clocks are used, and the adder also acts as a simple low pass filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.