ON Semi is seeing a marked increase in the number of image sensors deployed per car in ADAS functions. Its most recent introduction provides, among other features, flicker reduction. This is intended to eliminate, directly at the sensor, the strobing effect that can occur when the image sampling cycle 'beats' with the pulsed waveform driving LED tail-lights in other vehicles, or illuminated speed-limit signs.
The sensor also has a high dynamic range, substantially exceeding that of the human eye; and it is also the only sensor in its applications space, ON claims, to have ASIL B support. Using a 4-exposure capture cycle to achieve HDR (high dynamic range) the device can reach frame rates of up to 40 fps, and dynamic range of 120 dB.
The LED Flicker Mitigation (LFM) technology in the sensor eliminates high frequency LED flicker from traffic signs and vehicle LED lighting and allows Traffic Sign Reading algorithms to operate in all light conditions. The AR0231AT has a 1 / 2.7 in. (6.82 mm) optical format and a 1928 (horizontal) x 1208 (vertical) active pixel array. It uses 3.0 micron Back Side Illuminated (BSI) pixel with ON Semiconductor's DR-Pix technology, which offers dual conversion gain for improved performance under all lighting conditions. It captures images in linear, HDR or LFM modes, and offers frame-to-frame context switching between modes and has multiple data interfaces including MIPI, parallel and HiSPi. Other features include selectable automatic or user controlled black level control, spread-spectrum input clock support and multiple colour filter array options.
AR0231AT occupies an 11 x 10 mm iBGA-121 package and engineering samples are available now. It has an operating temperature range of -40 to +105C (ambient) and will be fully AEC-Q100 qualified. It will be available in mass production in 2016.
ON Semiconductor; www.onsemi.com