Analog-to-digital converter on CMOS with MOS capacitor
US5790063A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1996 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Dec 16, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/464
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An analog-to-digital converter is introduced which operates as an oversampled delta-sigma converter. The converter is implemented fully differentially, having doubled integrator capacitors (130, 230), comparators (180, 280), and feedback units (160, 260). In order to reduce the influence of parasitic capacities, the feedback units (160, 260) comprise cascoded switches (171-179). Internal auxiliary signals for controlling the feedback units (160, 260) return to zero at clock frequency. The converter can be used in an integrated signal processing circuit having analog and digital domains on one chip. The capacitors (130, 230) itself are implemented by MOS transistors with the same single poly process as the rest of the circuit. In a second embodiment of the invention, the analog-to-digital converter (500) comprises multiple comparators (580, 572, 573, 574), dynamic matching circuits (801, 802). The comparators (572, 573, 574) can received dithered input signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.