Differential Amp Pairs With High-Res ADCs

Introduced as the industry's first single-chip differential amplifier capable of driving 14-bit a/d converters at 70 MHz, the AD8351 supports 10-bit distortion performance at speeds up to 240 MHz. These performance levels are said to be accomplished via the company's proprietary eXtra Fast complementary bipolar and silicon-on-insulator manufacturing process. Users can adjust the common-mode voltage and set the gain from 0 dB to 26 dB, voltage gains from 1 through 20, via a single resistor. The device provides a bandwidth of 2.2 GHz with a gain of 12 dB. Noise spectral density is specified as 2.2 nV/rt-Hz, second and third order harmonic distortion as -79/-81 dBc at 70 MHz, and slew rate as 11 kV/µs. The amplifier operates on a 3V or 5V power supply and draws 27 mA of quiescent current. Operating over a temperature range from -40°C to +85°C, the device is specified at the common IF frequencies of 10, 70, 140, and 240 MHz. Available in a 10-pin microSOIC package, price is $3.69/1,000. ANALOG DEVICES, INC., Wilmington, MA. (800) 262-5643.