Circuit for detecting electrical signals at a given frequency
US6759941B2 · kind B2 · utility
1Cited by
11References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 18, 2001 |
| Grant date | Jul 6, 2004 |
| Priority date | — |
| Expiry date | Aug 27, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/007
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The circuit for detecting the frequency of binary signals includes a circuit for detecting rising edges in the binary signals, a measuring circuit for measuring the period between the rising edges which supplies a logic state, and a shift register whose input latch stores the logic state. Also, the detecting circuit includes a shift circuit for shifting logic states of the shift register, and a decoding circuit for decoding logic states of the register, and which supplies a signal validating the signals. The detecting circuit can be used in contactless chip card readers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.