Time constant automatic adjusting circuit, filter circuit system, and method of automatically adjusting time constant
US7865163B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2009 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Mar 19, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/1291
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A time constant automatic adjusting circuit comprises: a filter circuit varying a phase of an clock signal to be input so as to output the clock signal; a phase comparison circuit comparing a phase of an output signal of the filter circuit with the phase of the clock signal, and outputting a predetermined voltage when the phase of the output signal and the phase of the clock signal are the same; at least three comparators comparing the output voltage with a plurality of different voltages; an up-down counter counting a number of output bits of either one of the at least three different voltages in accordance with an output result of the comparators; and a control circuit varying the time constant of the filter circuit in accordance with the number of output bits counted by the up-down counter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.