Onsemi Unveils Image Sensors That Boost Battery Life by 40 Percent
Aimed at Smart Homes and Offices, this new image sensor family promises to blend high performance with ultra-low power draw while moving key functionality from the image processor on to the sensor.
The use of vision systems is rapidly expanding both in consumer and in industrial applications. The rising need for video conferencing cameras, security cameras, machine vision, AR/VR/XR headsets and other vision systems are leading to increasing demand for high performance image sensors.
Many of these applications will require battery or solar power systems which means that low power use is potentially as important as image quality.
The Onsemi Hyperlux LP image sensors
With all that in mind, today Onsemi announced its new Hyperlux LP family of sensors with both power draw and image quality as priorities. The family includes three back-side illuminated (BSI) Stacked CMOS digital image sensors. The sensors have a 1.4 μm pixel size at resolutions of 5 MP (2592 × 1944) for the AR0544, 8.3 MP (3840 × 2160) for the AR0830 and 20 MP (5120 × 3840) for the AR2020. The original Hyperlux family was introduced back in May.
Wake on Motion Within the Image Sensor
All three sensors support in-sensor wake on motion (WOM), which contributes to power savings. The sensors can remain in a standby mode until motion is detected. Many other sensors require the wake on motion logic to reside in the processing side of the device. Doing so requires more power to the sensor even while the main electronics are in low power mode. The new Hyperlux LP sensors have the WOM logic in the sensor allowing it to also be in low power standby along with the rest of the system.
Wake on motion within the sensor for system standby power reduction
By moving the WOM into the sensor, the overall system can be held in low-power mode until motion is detected. The Hyperlux sensors require less than 2 mW standby power and can wake to full power mode in less time than it takes to snap a photo.
Smart Region of Interest Allows for Bandwidth Reduction
The AR2020, 20 MP sensor also has a feature called Smart Region of Interest (SmartROI). SmartROI allows the system to select a smaller area within the sensor. Many applications, such as video conferencing or traffic cameras don’t require the entire image in high resolution.
For example, a traffic camera may need full resolution coverage in the area that shows an intersection, but not in areas adjacent to the road surface. SmartROI will allow designation of that area as being full resolution while the rest can be viewed at a lower resolution to reduce overall system bandwidth requirements.
Bandwidth reduction with SmartROI (Smart Region of Interest)
By cropping the high resolution imagery to the region of interest, applications such as video conferencing or traffic cameras can provide the detail necessary for operation at a significantly reduced bandwidth.
While this is a common feature of vision systems, current systems perform the operation downstream with software. With the AR2020, the region selection and discrimination is handled within the sensor, reducing bandwidth at the start and reducing processing load downstream.
Near Infrared Optimized for Better Low Light Performance
Another important optimization comes in the form of the sensor wavelengths. The sensors are highly sensitive in near infrared, which enhances low light performance.
Better low light performance reduces image noise, allowing for more accurate image processing and reduces the need for external lighting sources when used in dark environments.
Vision is Becoming Ubiquitous
Vision is coming to nearly all electronics devices in the same way that wireless connectivity has. And, as vision becomes ubiquitous, new applications open and existing applications will dramatically expand in scope. The Onsemi Hyperlux LP sensors are designed for low power, high image quality and low-light sensitivity; three of the key requirements for the next generation of vision equipped devices.
By moving key features, such as wake on motion and region of interest focus onto the sensor, the image signal processing load is reduced allowing for more choices in system optimization.
All images courtesy of Onsemi
For battery operated devices the game of low power (or “no power needed”) is for sure an evolution. In terms of R&D where can you get most power saving gains, from battery technology or in silicon design? I ask it that way because there’s a lot of money being spent on making batteries more energy dense, but if silicon can save 40% then why would I need energy dense batteries?