Tone detector
US9341661B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 15, 2013 |
| Grant date | May 17, 2016 |
| Priority date | — |
| Expiry date | Jun 9, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/19
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A tone detector is disclosed that is realizable in digital embodiment on a single integrated circuit die and does not require external components, such as a discrete capacitor. An input connects to a comparator, which in turn connects to one or more edge detectors and a flip flop. The edge detector outputs a pulse responsive to a detected edge. A counter is reset by the pulses from the edge detectors thereby preventing the counter from reaching a maximum value, which would otherwise be output from the counter and provided to a flip flop to clock in the comparator output at the D input to the flip flop. In operation, the comparator generates a rail to rail signal responsive to a received tone, which in turn is clocked through the flip flop as a logic high output indicating presence of a tone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.