Integrated MOSFET resistance and oscillator frequency control and trim methods and apparatus
US5243239A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 1992 |
| Grant date | Sep 7, 1993 |
| Priority date | — |
| Expiry date | Sep 4, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/011
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
For use in integrated circuit systems wherein both filter time constants and oscillator frequency each need a suitable reference, both the filter and the oscillator are referenced to common reference circuitry through a suitable control loop. Because the fundamental control parameters of the oscillator and the filter are time-period and time-constant respectively, the oscillator and the filter are implemented in a manner where the monolithic passive elements setting the fundamental control parameters (time-period and time-constant) are of the same type. This has the advantage of close tracking through process and ambient variations. Monolithic capacitors on the same chip are used as one of the common passive elements between the oscillatorand the filter to set the time-period and time-constants, respectively, adjustable through adjustment of control currents. The monolithic implementation of the Control Block is such that by tuning the oscillator frequency to the appropriate value through setting of the respective control current, the filter time-constants also are appropriately set to satisfy the Nyquist criteria for a sampling rate referenced to the oscillator frequency. Trimming…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.