Threshold crossover detector with improved digital noise rejection
US5278462A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 24, 1992 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Apr 24, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/1536
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The detector applies an analog input signal through respectively positive and negative offset voltages to the inputs of two comparators, one of which produces a first output signal as the input signal passes beyond a predetermined minimum voltage in the positive going direction, and the other of which produces a second output signal when the input voltage exceeds a minimum predetermined value in a negative going direction. The input signal is also applied directly to the input of a third comparator the output of which produces a third signal each time the input signal crosses over zero voltage in a positive going direction. The first and second comparator output signals are applied to the reset and set terminals, respectively, of a first flip flop. The output of this first flip flop, and the output of the third comparator are applied through an AND gate to the set terminal of a second flip flop. The second flip flop produces at its output a digital signal precisely at the time that a signal is produced at the output of the third comparator, provided the outputs of the first and second comparators have been successively generated in the cycle of the input voltage immediately precedi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.