Method and apparatus for the generation of long time constants using switched capacitors
US5552648A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1994 |
| Grant date | Sep 3, 1996 |
| Priority date | — |
| Expiry date | Feb 22, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A switched capacitor (12) providing an effective resistance having a relatively long time constant. The switched capacitor (12) includes a technique for switching an input switch (14) associated with the capacitor (12) between a first input potential and a second input potential where the second input potential is proportional to the first input potential. In one specific implementation, the capacitor is a primary capacitor (30) having a three position input switch (46) that is switchable between a ground contact (48), an intermediate contact (42) and the input potential, and a three position output switch (50) that is switchable between a first ground contact (56), a second ground contact (54) and an output potential. A secondary capacitor (32) includes a two position input switch (34) that is switchable between the input voltage and a ground contact (38), and an output switch (40) that is switchable between a ground contact (44) and the intermediate contact (42). The clocking frequency of the primary capacitor (30) enables the input switch (46) to be switched from the ground contact (48) to the intermediate contact (42) to the input voltage. When the input switch (46) of the prim…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.