STMicroelectronics, a world leader in CMOS image sensor technology, has introduced a leading-edge solution for mobile phone cameras. Consisting of the VS6552 CMOS Image Sensor module and the STV0974E Mobile Imaging DSP (Digital Signal Processor), the new mobile camera kit offers image quality equivalent to CCD (Charge Coupled Device) image sensors without the well-known disadvantages of CCD technology*.
Designed for high volume manufacturing while maintaining very high levels of reliability, the new solution is the result of a radical system level approach to imaging in mobile phone applications, combined with a new CMOS process, known as HCMOS7i, which has been designed for exceptional light sensitivity, and an advanced imaging DSP based on a high performance, fully pipelined architecture.
"The VS6552 is the result of concurrent engineering of the CMOS imaging process, of the sensor design and of the optical stack," said Marc Vasseur, General Manager of ST's Imaging Division. "ST unique mastery of the whole imaging chain allows it to make the optimal trade-offs required to produce a world-class image quality within the demanding low power consumption, EMC and cost constraints inherent in mobile phone applications."
The VS6552 is the first device to be fabricated in ST's new HCMOS7i process and outperforms all previous ST sensors by delivering VGA images at light levels as low as 1 Lux**. Combined with a high quality optical stack and operating at a full rate of 30 frames per second, this 10 x 8 x 6 mm small optical module (SmOP) delivers high image and video quality even under extreme low-light conditions. Minimum illumination is less than 1 Lux (0 dB SNR with F2.8 lens) and dark current is 30 electron/s at 25 degrees C. Its LVDS-based serial video interface is engineered to minimize EMC (Electro-Magnetic Compatibility) effects, ensuring seamless camera integration even close to radio areas. The interface supports future higher resolutions, with a choice of low-cost socket or flexible circuit attachment methods.
Housed in a 56TFBGA 6 x 6 mm lead-free package, the STV0974E Mobile Imaging DSP is a complete mobile digital still camera processor, incorporating sensor control and signal conditioning, image enhancement, image cropping and scaling, viewfinder generation and image capture, including JPEG file generation. Targeting MMS (Multimedia Messaging Service), the device simplifies both short video clips and limited file size image capture. As an alternative to the classic ITU-R 601/656 8-bit parallel video interface, the 8-bit MCU host interface with up to 10 Kbyte FIFO allows camera integration in legacy, cost-sensitive mobile environments. The STV0974E supports 8 and 16-bit RGB output formats for direct viewfinder on the phone's LCD, while an RGB dithering option allows for a high quality viewfinder on displays with color depth as low as 4096 colors.
The chipset requires a 2.5 to 3.0V analog and 1.8V digital power supplies and a single 6 to 26MHz clock to operate. Internal power supply and clock management functions result in a 30 micro-amps current in standby mode, and maximum 170mW while streaming VGA JPEG at 30 frames per second.
Ideal for use in Camera/MMS mobile phones, Bluetooth and WiFi mobile cameras, PDAs and other portable terminals, the chipset is currently available in engineering samples and is supported by USB 2.0 Demonstration and Evaluation kits. Volume production is scheduled for March 2004.
ST has been shipping millions of CMOS camera phone solutions for over a year and has built an extensive experience in the assembly and testing of optical modules in its Singapore plant.