Light sensor helps save backlight power

AMI Semiconductor has developed an ambient light sensor for electronics displays and automotive applications.

AMI Semiconductor has developed an ambient light sensor for electronics displays and automotive applications.

Emulating the human eye, the AMIS-74980x sensor provides an output proportional to ambient light, which allows the display controller to adjust the brightness and contrast.

This not only helps reduce eyestrain from glare and reflection, but also controls power dissipation and minimises frequent battery recharges or replacements in portable devices.

Using AMI Semiconductor's proprietary CMOS image sensing technology, the AMIS-74980x ambient light sensor provides design flexibility and cost savings for devices with illuminated displays.

It is an ideal savings solution for use in cellphones, PDAs and handheld displays, LCD monitors, portable DVD players, notebook PCs, large format LED displays, and MP3 players.

In automotive applications, it is well suited for in-car entertainment video systems, GPS displays, headlamps, rear-view mirrors and dashboards.

AMI Semiconductor's AMIS-74980x family of ambient light sensors performs equally well with light sources ranging from natural sunlight to fluorescent, conventional incandescent and halogen lamps.

An important feature of the AMIS-74980x is its low dark current, enabling the display controller to adjust the brightness of the display even in low light-level environments.

"The AMIS-74980x family of ambient light sensors, with its lower cost and small form factor, benefits price- and size-sensitive mobile applications", said Jon Stoner, CTO of AMI Semiconductor.

"The family offers multiple output options, programmability, an innovative way of lowering dark current, and low power consumption, which aids system designers in product development and improves the battery life of handheld devices and battery-operated consumer appliances".

Traditionally, sending text messages via cellphones or instant messages from PDAs causes the display to remain on for long periods of time, which rapidly drains battery life.

With the introduction of AMI Semiconductor's ambient light sensor, consumers can communicate in a wider variety of lighting environments for longer periods of time.

Because the AMIS-74980x is an analogue/digital output device, it features performance over the 3.0 to 3.6V supply voltage range, operating frequency of 10-100kHz, and the 0 to 70C temperature range.

The AMIS-74980x is currently available from AMI Semiconductor.

The digital version of AMIS-74980x is priced at US $0.75 in quantities of 10,000.

The analogue version is priced at $0.55 in quantities of 10,000.

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