Circuits for realizing an optical isolator
US5061859A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1989 |
| Grant date | Oct 29, 1991 |
| Priority date | — |
| Expiry date | Sep 13, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F55/25
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An optical transmitter/receiver pair has an integrated CMOS circuit that provides a current flow to a pre-biased solid state light emitting device (LED) in response to the presence or absence of a digital input signal. The current flow is augmented at the rising and falling edges of the input signal to enhance turn-on and turn-off speed of the LED. The LED is optically coupled to a photodiode that produces a current flow in response to illumination. The photodiode is shielded from spurious electronic noise by a transparent shield and the output of the photodiode is amplified to produce an output voltage, which is connected to a capacitively delayed voltage divider. The voltage divider generates a time delayed threshold voltage connectable along with the output voltage to the inputs of a comparator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.