Amplifiers Provide Flexible Bandwidth, Gain Control, Input Voltage

The unique architecture of the VCA82x family of integrated wideband variable-gain amplifiers provides designers with a highly flexible combination of bandwidth, gain, and analog input voltage. The VCA821 and VCA824 offer the industry’s largest bandwidth of 420 MHz for a gain of 10 V/V, which is over 300% larger than comparable devices, according to the company. They also provide the fastest slew rate of 2500 V/µs, which is 40% faster than what is available today. The VCA820 and VCA822, meanwhile, offer a competitive 150-MHz bandwidth and slew rate of 1700 V/µs. The amplifiers give users the ability to set the maximum gain anywhere from 0 dB (1 V/V) to 40 dB (100 V/V) with external resistors. An externally supplied gain voltage can then be varied dynamically to implement a greater than 40-dB gain adjust range. Designers can also choose between linear gain in dB/V or V/V. The amplifiers are pin-compatible for easy upgrading to higher bandwidth and to allow switching between dB/V and V/V. The VCA82x amplifiers are available today in a SOIC-14 or MSOP-10 package. Suggested resale pricing in quantities of 100 is $4.35 for the VCA820 and VCA822, and $5.20 for the VCA821 and VCA824. Samples and evaluation modules (DEM-VCA-SO-1B and DEM-VCA-MSOP-1A) are also available. TEXAS INSTRUMENTS INC., Dallas, TX. (800) 477-8924.