Colour sensor provides precise measurement on darker colours

A member of the ams JENCOLOR family of colour sensors, the AS73211 provides enhanced optical characteristics because of its filter-on-glass technology. It offers light and colour measurements closely matching a typical human eye’s perception of light, as defined by the industry-standard CIE 1931 tri-stimulus model of human eye function.

The new sensor measures colour accurately at light levels from 0.4 lux up to 208 klux - a wide dynamic range of 250,000,000:1, enabling effective operation in widely varying lighting conditions, from moonlight to bright sunshine.

The high sensitivity of the AS73211 makes it particularly suitable for precise measurements of dark objects and materials, such as black pixels on a display screen, dark skin, black paint or soil, even in low light conditions.

The sensor’s 24-bit integrated light-to-digital converter offers the ability to configure the conversion time in a range from 125µs-16s, allowing users to adjust operation for optimal balance between speed of measurement and precision.

The AS73211’s low power consumption and an automatic power-down mode support use in low energy and handheld applications.

Applications which will benefit from the high performance and small size of the AS73211 include:

• Medical and high end professional displays, for white colour balancing and display colour management
• Spotlights, projection systems and video wall modules, for control of power LEDs
• Professional hair and skin tone analysers
• Professional and industrial colour picking and matching equipment
• Aviation display and lighting controls - a single AS73211 can support feedback control over the entire output range from full brightness to deeply dimmed

In these and other applications, the AS73211’s integrated silicon interference filter provides stable performance over time and temperature, and with no further calibration required for the lifetime of the end product.

The very high performance of the device is due in part to the unusually large sensing area on the surface of the chip. Because of the advanced electrical and optical design of the device, however, ams is able to house it in a compact 16-lead QFN package which is also highly resistant to the effects of exposure to ultraviolet radiation.

The stable thermal characteristics of the filter mean that ams is able to qualify the AS73211 for operation over a wide temperature range of -40°C to 125°C. Internal compensation based on readings from the AS73211’s integrated temperature sensor ensure that the accuracy of colour measurement is maintained over the entire operating temperature range.

“With the introduction of the AS73211, ams is extending its portfolio of XYZ sensors to address the requirements of high end consumer and industrial devices. A unique ams design featuring a large detector area and an integrated 24-bit light-to-digital converter has produced a sensor with the highest sensitivity and widest dynamic range of any XYZ sensor on the market,” said Markus Busz, Marketing Manager at ams.