MLX75026 with a fully integrated IR filter improves system stray light performances
Tessenderlo, Belgium, 15 September 2021 - Melexis has developed a new version of its time-of-flight 3D camera MLX75026 with a fully integrated infrared bandpass (IRBP) filter. By integrating the IRBP, it is no longer required to include a separate IR filter in the lens or sensor assembly. This solution is unique in the industry. It reduces design complexity and cost, while creating more design choice when sourcing a lens.
Melexis, a global microelectronics engineering company, has introduced the MLX75026 with IRBP, an AEC-Q100 qualified QVGA time-of-flight sensor that further expands the third generation of ToF sensors from Melexis. The integration of an infrared bandpass filter removes the need to add a separate bandpass filter, which simplifies design and manufacturing while also increasing the choice of suitable, IR-friendly lenses.
The MLX75026 targets automotive use cases like driver monitoring (DMS), in-cabin monitoring, gesture control, safety applications related to airbag deployment, head-up display (HUD) driver alignment and industrial applications like automated guided vehicles (AGVs), elevator entry and (collaborative) robotics.
'An IR filter is mandatory in every ToF application to reduce out-of-band infrared light in the operating environment, which could otherwise lower the dynamic range of the sensor,' explained Gualtiero Bagnuoli, Optical sensors marketing manager at Melexis. 'A separate filter adds cost and complexity to a design, but by using the MLX75026 with IRBP filter, engineers can avoid both the cost and complexity, and explore the benefits of time-of-flight sensing more easily'.
The integration of the correct IR bandpass filter is not trivial: the passband must be adapted to the illumination and the filter shall accept light from a wide range of incidence at minimal spectral shift (optically hard filter). This facilitates the usage of ToF-lenses with high apertures (low f-number). Melexis is the only ToF sensor manufacturer currently offering this option, which is now available as a variant of the MLX75026. The MLX75026 offers software-compatibility with other Melexis gen 3 ToF sensors.
MLX75026 with IRBP filter has QVGA (320x240 pixels) resolution with a 1/4 inch optical format and supports 940 nm illumination. Configuration is implemented over an I2C interface and provides CSI-2 serial data output. The high integration, small size and low power consumption of the sensor, coupled with the integration of the IR bandpass filters, enables the design of compact and cost-effective ToF cameras for automotive, industrial and consumer applications.
Samples of the MLX75026 with IRBP filter are available now. A compact high-performance evaluation kit (EVK) will also be released.
Incorporating a Xilinx Zynq Ultrascale+ MPSoC, the EVK75026+ quadruples the data bandwidth and frame rate of the earlier EVK75026 evaluation kit, while taking up approximately half the mechanical size. It offers advanced pixel calibration and filtering functions, plus on-demand support for sophisticated features like ambiguous range extension, multi-path resolving and interference rejection. The programming interface (API), written in C language, includes wrappers that allow the kit to be used with both Matlab and Python.