Optocoupler circuit

US8260098B1 · kind B1 · utility

Assignee

• NXP B.V. · NL

Inventors

• Dusan Golubovic · Leuven, BE
• Gerhard Koops · Aalst, BE
• Tony Vanhoucke · Bierbeek, BE
• Rob Van Dalen · Veghel, NL

Key dates

• Filing date: Feb 17, 2011
• Grant date: Sep 4, 2012
• Expiry date: May 13, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/8262

Abstract

An optocoupler device facilitates on-chip galvanic isolation. In accordance with various example embodiments, an optocoupler circuit includes a silicon-on-insulator substrate having a silicon layer on a buried insulator layer, a silicon-based light-emitting diode (LED) having a silicon p-n junction in the silicon layer, and a silicon-based photodetector in the silicon layer. The LED and photodetector are respectively connected to galvanically isolated circuits in the silicon layer. A local oxidation of silicon (LOCOS) isolation material and the buried insulator layer galvanically isolate the first circuit from the second circuit to prevent charge carriers from moving between the first and second circuits. The LED and photodetector communicate optically to pass signals between the galvanically isolated circuits.