New Industry Products

40-V Amplifier Improves System Performance and Efficiency

June 16, 2014 by Jeff Shepard

Analog Devices, Inc. today introduced the industry's fastest operational amplifier for driving heavy loads at high voltage and high output current, including piezoelectric transducers, PIN diodes, laser diodes, power FETs, coils and CCDs. The 40-V ADA4870 amplifier delivers over 1A of output current at more than twice the slew rate (2500 V/νs) of competing high output-power amplifiers, enabling applications including higher accuracy, high-intensity focused ultrasound (HIFU) for medical equipment and higher efficiency envelope tracking solutions in small-cell base stations and military radios.

"We recently introduced an industry leading, highly efficient envelope tracking product line aimed at small-cell RF transmitters that must deal with complex waveforms, such as LTE," said Dave McIntosh, general manager, KCB Signal Solutions. "We developed one of our key compact circuits using Analog Devices’ ADA4870 amplifier, the only device with the ability to amplify our high-speed current and voltage waveforms while driving a low impedance load. The ADA4870 allows us to provide envelope tracking power amps with efficiencies exceeding that of class A/B and Doherty solutions."

In HIFU equipment used for medical treatment and procedures, the ADA4870 provides wide bandwidth (52 MHz) and high slew rate to facilitate the high-voltage pulses necessary to drive the piezoelectric transducer, increasing accuracy and replacing large, costly discrete solutions. In small-cell base stations and compact military radios, the ADA4870 improves power efficiency and extends battery life by assisting with the drive of the power amplifier’s (PA) low impedance bias control to track the envelope of the RF signal, only using as much power for the PA as needed to pass the signal.

In addition to HIFU and RF envelope tracking, the fast ADA4870 can be used to improve the driving of various high-capacitive and low-resistive loads including extending the bandwidth of high-voltage function generators and increasing automated test equipment drive capability and testing speeds, all while reducing solution size and cost. The ADA4870 is specified for operation from -40 to +85 degrees C. In lots of 1,000 pieces, the unit price is $8.50 for these 20-lead PSOP devices.