Date: 26/02/2009

Quad-channel VGA with 4 on-chip ADC drivers for PET scanners

Analog Devices introduced the AD8264 quad-channel VGA (variable-gain amplifier), an integrated device designed for PET (positron emission tomography) scanners, communication systems, and advanced video equipment. The AD8264 is the four-channel VGA and integrate four ADC (analog-to-digital converter) drivers, enabling to reduce PCB area and simplify layout by replacing eight components with a single device.

Some of the features include:

1. The AD8264 VGA has a single-ended output for wide-bandwidth applications, and auxiliary differential ADC drivers that operate with ADI's data converters.
2. It is also suited for wireless infrastructure equipment where its four DC-coupled channels and gain control allow communication-systems designers to adjust output-signal levels.
3. For advanced broadcast and video-security applications, this VGA improves picture quality by more accurately white-balancing RGB (red-green-blue) signals and better managing gain-trim calibration over the system's life.
4. Each of the AD8264's four linear-in-dB VGA channels has independent gain control.
5. Each channel comprises a high-impedance preamplifier, a high-speed VGA, and a differential output amplifier.
6. The AD8264's pinout provides single-ended output taps directly from the VGAs, which have a -3 dB bandwidth of 235 MHz, and balanced outputs from the 80-MHz output amplifiers.
7. Dual supply operation enables gain control of negative-going pulses such as those that photodiodes, photo-multiplier tubes, and video signal-sources generate.
8. With a 24-dB gain range, the AD8264 features a gain-control interface that provides a precise 20 dB/V linear-in-dB scale.
9. A common gain-control reference for all channels simplifies wiring.
10. The differential gain-control structure accommodates a range of common-mode operating points, simplifying the interface to any analog or digital control source.
11. A VOCM pin sets the common-mode voltage of the differential output stage to match modern single- supply ADCs, and allows for dc level-shift of the output.
12. Power consumption is 125-mW per channel at ±3.3V.
13. Temperature Range: -40°C to +85°C

Availability:
Samples are available now and will be available with full production in March 2009

Package: 40-lead LFCSP
Price: $11.95 each per 1K pieces

For more details go to: www.analog.com