Switched-capacitor frequency-to-current converter
US6798372B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 2003 |
| Grant date | Sep 28, 2004 |
| Priority date | — |
| Expiry date | Apr 1, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K9/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency-to-current converter operative to convert a clock frequency to an output current is described; the frequency-to-current converter ensures that the output current increases linearly with the clock frequency. The frequency-to-current converter may be incorporated in analog-to-digital converters driven by clocks with variable frequencies. The frequency-to-current converter employs an integrator circuit, used to compare an input reference voltage and a current feedback into a sampling capacitor. At steady state, the feedback current is just sufficient to discharge the sampling capacitor to a fixed voltage. The core of the frequency-to-current conversion circuit includes one opamp, two capacitors, one feedback transistor and a few switches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.