Analog Devices' announced two, voltage-feedback amplifiers, the AD8057 (single) and AD8058 (dual). These devices offer a bandwidth and slew rate typically found in current-feedback amplifiers at prices normally associated with lower performance amplifiers. This balance of cost and performance makes them well-suited for many high-speed applications and reduces the need to qualify a variety of specialty amplifiers.

At just $0.79 for the single AD8057 and $1.47 for the dual AD8058 in 10k quantities, these new amplifiers provide a wide bandwidth of 325 MHz (G= +1), voltage noise of 7nV/Hz, and a total harmonic distortion of just 85 dB @ 5 MHz. They offer the noise and distortion performance required for high-end video systems as well as the dc-performance parameters rarely found in high-speed amplifiers. Additionally, the AD8057/58 are low-power amplifiers (22 mW on +5 V supply) with a wide supply range from 3 V to 10 V. Additional information on the AD8057/8 can be found at www.analog.com.

The combination of performance, size, power and cost advantages of the AD8057 and AD8058 makes them very well-suited for variety of consumer and industrial applications. Furthermore, the AD8057/58 allow engineers to combine the ease-of-use of voltage feedback amplifiers with the performance of current-feedback amplifiers at price points that compete with discrete transistor designs in high-volume applications.

The news here is that Analog Devices have managed to produce a voltage-feedback amplifier (VFA) that looks like a current-feedback product in its specs. A VFA is more easily designed into a circuit by the majority of users. The parts are also priced at commodity levels and many users would have problems designing a discrete solution with as good a performance at anything like these prices. The 325-MHz gain-bandwidth product and noise voltage are particularly nice.

Both these parts will sell extremely well and ADI need to produce a triple version quickly. As noted, the AD8057 is priced at $0.79 and the AD8058 at $1.47 in 10 k-piece lots.