Gated integrator preamplifier for infrared data networks
US5790295A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 28, 1995 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Aug 28, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/114
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for receiving infrared signals are provided. The circuit includes preamplifier that includes an integrator that charges based on light detected by a photodiode. The circuit includes a warning circuit that generates a warning flag when the charge on the integrator exceeds a predetermined level. To prevent the integrator from saturation, digital logic resets the preamplifier by dumping the charge on the integrator in response to the warning signal. The digital logic is also configured to reset the integrator at predetermined intervals. When the incoming signal is encoded using pulse position modulation, the interval at which the integrator is reset is the length of a single time slot in the pulse position modulation frame. A sample and hold circuit is provided to hold a previous output of the preamplifier. The difference between the previous output of the preamplifier and the current output of the preamplifier is compared with a threshold voltage to detect pulses on the incoming signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.