Differential drivers optimized for driving ADCs from DC to 100 MHz.

For example, the ADA4937-1 has 16-bit performance up to 40 MHz, 14-bit performance up to 70 MHz and 12-bit performance up to 100 MHz. In applications such as wireless infrastructure equipment, the improved ADC performance translates into higher data rates with fewer errors. When used
in data-acquisition systems, the new driver ICs allow the ADCs to provide more accurate data collection at faster speeds, resulting in higher system throughout and overall performance.

Lower distortion levels allow designers to maintain the quality of key ADC performance characteristics, including spurious-free dynamic range and signal-to-noise ratio, leading directly to improved system performance, said Jim Doscher, product line director, High-Speed Linear Products, Analog Devices, Inc. The drivers also make it very easy to level shift the signal to match the input range of the ADC without ac coupling, preventing the loss of low-frequency information.

The ADA4937-1 and ADA4938-1 ADC drivers combine the low noise and distortionlevels required to drive the high-speed ADCs found in today's wirelessinfrastructure and instrumentation equipment. Ideal for single 3-V to 5-V power supplies, the ADA4937-1 achieves an industry-best distortion
of -120/-102 dBc at 10 MHz, -98/-100 dBc at 40 MHz and -84/-90 dBc at 70 MHz. The ADA4938-1 works over a 5-V to 10-V supply range and achieves industry leading distortion of -112/-108 dBc at 10 MHz, -96/-93 dBc at 30 MHz and -79/-81 dBc at 50 MHz in dual supply applications. The ultra-low
distortion of the ADA4937-1 and ADA4938-1 is achieved through the use of ADI 's XFCB-3, a proprietary and specialized silicon germanium (SiGe) silicon-on-insulator (SOI) process technology.

The devices also feature an internal common-mode feedback architecture, which allows the output common-mode voltage to be controlled by an externally applied voltage. This bridges any gap between the output range of the component before the ADC and the input range of the ADC, eliminating the
need for ac coupling, and making the drivers well suited for dc coupled applications such as data-acquisition instruments and baseband communications systems.

The ADA4937-1 and ADA4938-1 are sampling now with full production scheduled for April, 2007 and June, 2007, respectively. The devices are priced at $3.79 per unit in 1,000-piece quantities in a 3 mm × 3 mm LFCSP (lead frame chip scale package) and are specified over an operating temperature range of
0 degrees C to + 85 degrees C.