Comparator with application in data communication
US5386207A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 23, 1992 |
| Grant date | Jan 31, 1995 |
| Priority date | — |
| Expiry date | Jun 23, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45732
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A comparator that may be used in data communications transmission lines, in particular, an Ethernet Twisted-Pair line. The comparator accepts as input the differential voltage from the transmission lines. The comparator uses feedback circuitry to monitor particular voltages within the comparator and adjust them as necessary to mitigate the effect of bias offset within the comparator that may result from, for instance, temperature driven device parameter variations. The comparator also minimizes the effect of power supply noise. The feedback circuitry ensures that as the comparator input differential voltage approaches zero (i.e., when the comparator outputs should switch from a high voltage to a low voltage or vice versa), the input of a comparator output amplifier is situated in the middle of the high gain region of the output amplifier, ready to quickly trigger switching of the comparator output when the comparator input differential voltage crosses zero volts. In one embodiment, the feedback circuitry comprises an operational amplifier and two resistive-capacitive structures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.