Tuning circuit for continuous-time filters and method therefor
US5187445A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 28, 1991 |
| Grant date | Feb 16, 1993 |
| Priority date | — |
| Expiry date | Oct 28, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J2200/10
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tuning circuit (30) provides selection signals to a passive component array (80) in a continuous-time filter (70) to compensate for wide variations in values which are encountered in integrated circuit processing. The tuning circuit (30) includes at least one capacitor (46) and at least one resistor (31), and a plurality of either capacitors or resistors. A largest component is enabled and an integration of a reference current during a predetermined period is performed. If the integration provides a voltage greater than a reference voltage, then a corresponding selection signal is set and the component is selected. Successive integrations are performed to determine which components are enabled by corresponding selection signals in order to enable a combination of components which most closely integrates the reference current to the reference voltage. When selection signals corresponding to all components have been determined, the selection signals are applied to corresponding components in the filter (70).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.