Lumileds and Melexis demo IR LEDs for Time-of-Flight
High frequency operation of infrared light sources is rapidly gaining interest for various Time-of-Flight (TOF) applications in automotive, industrial and consumer segments. Due to the fast switching requirements of these applications, mostly VCSELs are being considered. VCSEL technology, however, also comes with its drawbacks, including mass volume availability, required eye-safety measures and high cost.
Now engineers from Lumileds and Melexis have shown operation up to 40MHz Luxeon IR LEDs enabling Time-of-Flight applications in 940nm and 850nm with range of 3 metres.
To demonstrate this, the teams from Lumileds and Melexis have developed an evaluation kit.
“The illuminator evaluation kit developed by Lumileds reduces the rise and fall times of the light pulses to 6 ns, which is a factor of four over other similar LED devices. This is enabled by optimising the combination of improved peak current response of the Luxeon IR LEDS, the PCB design and boost electronics. The illuminator card enables an LED-based TOF system with accuracy and range comparable to VCSEL-based solutions, while reducing the overall system cost,” said Erno Fancsali, director CPAT EMEA at Lumileds.
“This break-through in high-frequency operation of Luxeon IR LEDs enables new TOF applications previously limited by cost or eye-safety constraints. This development will help to bring affordable and eye-safe distance measurements to a much broader range of products such as driver monitoring systems, logistics navigation, gesture recognition systems and drones. The Lumileds LED illuminator is available in 60°, 90°, and 150° fields of view and for 850nm and 940nm, by request,” said Wouter Schrama, senior product manager for the Luxeon IR Family at Lumileds. “The joint evaluation kit with Melexis can help our customers reduce their development time significantly and enable them to successfully enter the market”.
“The Lumileds solution pairs well with our new Automotive QVGA TOF chipset and will help accelerate the adoption of TOF systems, at an affordable cost point; the performance of the system in terms of range and accuracy provides a compelling value proposition for the emerging TOF systems,” said Gualtiero Bagnuoli, product marketing manager at Melexis.
Lumileds and Melexis have reported the results in a whitepaper that can be downloaded from the Lumileds website: https://www.lumileds.com/uploads/788/WP35-pdf
