STMicroelectronics (STM - distributed by Braemac ) claims to have produced prototypes of silicon-based optocouplers that deliver similar performance to existing non-silicon devices at a reduced cost by exploiting established low cost silicon manufacturing processes.
The physical properties of pure silicon have traditionally resisted attempts to make the material emit light. Instead combinations of more expensive compound semiconductors such as gallium, arsenic and indium have had to be used.
STM, however, claims to have developed silicon-based devices that can produce over 1 mW of emitted light power per square millimetre of silicon to efficiencies comparable to existing compound semiconductors.
As a result, the technology could be used to integrate all three functions of light emission, light waveguides and light detectors onto a single low cost and easily manufacturable silicon chip. This makes it applicable to a wide range of light emitting products and applications including optocouplers.
“Given that we already know from our current research that it will be possible to increase this performance by at least another order of magnitude, we are on the threshold of opening up entirely new industrial applications in the fields of displays and even solid state illumination,” claims Dr Salvo Coffa, a research director at ST.
“In addition to targeting the large existing market for conventional optocouplers, STM [intends to] aggressively pursue these novel applications.”
STM has signed a license agreement with Ericsson Technology Licensing for Ericsson’s new Bluetooth baseband core, which implements the complete range of mandatory Bluetooth 1.2 features.. ST will embed the Ericsson Core Bluetooth Baseband Platform Q-E1 in future Bluetooth products, starting with a single-chip Bluetooth solution with full V1.2 functionality that is currently in development.
Products compliant with the Bluetooth V1.2 specification offer features such as faster connection times, enhanced voice quality and adaptive frequency hopping and better scatternet functionality, for improved coexistence with other wireless technologies. The company's device is said to be fully compliant with the new standard, backwards compatible with all V1.1 solutions.
“We chose Ericsson due to their large base of experienced staff in Bluetooth wireless technology,” says Jacques Wenin, ST's Bluetooth business unit manager.