Optical image stabilizer driver IC for smartphone and tablet cameras

With the RAA305170GBM, product developers can bring high performance on par with that of standalone digital cameras to the smartphones or tablet PC camera modules. This level of performance allows smartphones and PCs to meet general consumer demand for camera functionality that enables them to capture high-quality video and still photos without ever missing a good shot, while uploading these videos and still photos to the web immediately without any need for image processing.

In recent years the demand for smartphones has grown rapidly within the mobile phone market, with matching increases both in the number of mobile Internet users and in the variety of applications and content. In addition, as the proportion of video among the images posted on the Internet has grown, consumers have come to demand higher pixel counts and more advanced functionality in their smartphone and tablet PC cameras. This has led to a growing demand in smartphone products market for image stabilization functionality.

Smartphones and tablet cameras need optical image stabilization function because they are susceptible to blurry images caused by shaking. Although low-cost electronic image stabilizers are widely used in smartphone cameras, the stabilization functionality tends to become less adequate as the camera resolution increases. Digital cameras can prevent blurry images caused by shaking through complementary functions such as diaphragm and high-speed shutter. Smartphone cameras, on the other hand, have limited space and they require alternate measure.

The image stabilization technology addresses these quality concerns by aligning the lens with the shaking of the camera, leveraging the technology developed by Renesas, used in compact digital cameras. The technological innovations accumulated in this way are incorporated into this new OIS driver IC, which is capable of three voice coil monitor drivers, as the first product with this capacity for the smartphone and tablet market.

Key Features of the RAA305170GBM: (1) The first OIS driver IC available with three systems of sensor/driver circuits for smart phones, raising the performance of functions such as Image Stabilization AF: Three systems of sensor / driver circuits can independently control three VCM actuators and the corresponding to closed loop control of AF, contributing to high performance of OIS and high-speed AF control.

(2) RL78 CPU core with servo control DSP for high-performance image stabilization using parallel processing: Processing is divided between the RL78, which detects and processes data on lens position gap, and the DSP, which drives the image stabilization lens. This enables excellent image stabilization performance with low power operation by a low clock frequency and with high-speed servo response by the servo control DSP.

(3) Support for actuator noise reduction and thermal drift compensation: The on-chip DSP makes it possible with digital filters to reduce audible noises from actuator operation and to decrease gyro sensor output drift due to temperature variations. In addition, a variety of actuator types can be accommodated, enabling support for stabilization methods such as module tilt, lens tilt, and lens shift.

(4) On-chip flash memory for rapid camera startup so no photo opportunities are missed: The on-chip nonvolatile flash memory eliminates the need to download firmware from an external device. As a result, the CPU startup time following power-on is reduced from the 40 milliseconds with previous Renesas products with no flash memory to only 0.7 msec. for the RAA305170GBM. This means that all opportunities for a good shot will never be missed.

By storing the control firmware and data in flash memory, changes to the product specifications or control parameters can be accommodated through firmware updates and can be updated after the product has entered mass production. It is also possible to store data such as model-specific actuator trimming values in the flash memory, and access this data very efficiently. Renesas plans to actively promote sales and introduce new products in this market and targets to achieve a 50% market share in this product category by 2015.

Product Specifications of the RAA305170GBM: Pricing and Availability: Samples of the RAA305170GBM are available now, priced at US$10.0 per unit. Mass production of the RAA305170GBM is expected to reach a scale of 10,000,000 units per month in March 2014.