Single-chip signal processors improve image acquisition
The AD9978A and ADDI7004 HD image signal processors enable high-resolution, high-speed sampling of signals from advanced image sensors, while consuming only 280mW and 530mW, respectively. Thus they are suited for DSCs, camcorders, scanners and other imaging systems.
"Until today, high-performance imaging system designers were forced to use multiple high-power components to sample image signals at HD rates," said Stuart Boyd, product line director, digital imaging systems, ADI. "By integrating high-performance signal conditioning circuitry, a 14bit data converter, and a precision timing core into a single HD image acquisition solution, designers can achieve an unequalled combination of speed and accuracy in high-speed, high-resolution digital imaging systems, while eliminating the power dissipation limitations that restrict portability and increase design cost."
The AD9978A and ADDI7004 devices extend ADI's family of AD997x image signal processors for high-speed digital imaging applications. Each channel integrates a complete analogue front-end comprising a black-level clamp, a correlated double sampler, a 10bit variable gain amplifier, and a 14bit ADC. Analog ('ue'?) Devices' Precision Timing core provides adjustments for the CDS and sample-and-hold amplifier clocks with 210ps resolution at 75MHz (ADD9978A) and 217ps at 72MHz (ADDI7004). The AD9978A and ADDI7004 also contain a reduced range LVDS interface for the image-data outputs to increase performance and reduce EMI issues.
The AD9978A and ADDI7004 reduce component count and power consumption without sacrificing performance, dynamically lowering power consumption at lower frequencies to extend battery life. The power consumption of each device is proportional to its sampling frequency. Both high-resolution image signal processors support designers' efforts to standardise their image sensor interface designs across multiple platforms, cutting the need to change or add additional components and reducing overall system cost across several models. Additionally, the AD9978A offers pin-for-pin compatibility with the industry-standard AD9978 14bit CCD signal processor, enabling designers to easily change existing designs to deliver high-end performance.