ADA4937 and ADA4938 differential amplifiers from Avnet
Analog Devices, Inc. has extended its family of innovative differential amplifiers by introducing two new devices with distortion levels 10 dB lower than competing driver ICs. The ADA4937-1 and ADA4938-1 differential drivers are optimised for driving high performance 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 allows 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. The drivers also make it easy to level shift the signal to match the input range of the ADC without ac coupling, preventing the loss of low-frequency information.
About the ADA4937 and ADA4938 ADC drivers
The ADA4937-1 and ADA4938-1 ADC drivers combine the low noise and distortion levels required to drive the high-speed ADCs found in today’s wireless infrastructure and instrumentation equipment. Ideal for single 3-V to 5-V power supplies, the ADA4937-1 achieves a distortion of –120/–102 dBc at 10 MHz, –98/–100 dBc at 40 MHz and –84/–90 dBc at70 MHz.
The ADA4938-1 works over a 5-V to 10-V supply range and achieves 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 specialised silicon germanium (SiGe) silicon-on-insulator (SOI) process technology.
The ADA4937 and ADA4938 ADC Drivers, available from Avnet, 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.
27-Feb-2007