ADI’s ADA4091-2 dual rail-to-rail op amp delivers industry’s best combination of low offset, low offset drift and wide gain-bandwidth across a variety of sensor inputs, while over-voltage protection circuitry prevents phase-inversion errors.

Norwood, MA (09/17/2008) - Analog Devices, Inc. (ADI), a world leader in semiconductors for signal processing applications and leading developer of amplifier technology, today introduced a highly integrated precision operational amplifier (op amp) with on-chip over-voltage protection circuitry. The ADA4091-2 precision op amp affords industrial equipment designers the industry’s most reliable, accurate, easy-to-use alternative to competing discrete analog input solutions.

“Industrial amplifiers are subject to fault voltages from a variety of sources, including electro-magnetic interference, damaged cabling, lightning strikes and other disturbances on the power grid, incorrect hookups to other system components and power-line surges when power to the system is restored after routine service or equipment upgrades,” said Steve Sockolov, product line director, Precision Signal Processing, Analog Devices. “Such over-voltage conditions can cause phase inversion or damage the amplifier and other circuitry, resulting in system lock-up or outright failure.”

The ADA4091-2 op amp’s performance is fully specified, including the device’s on-chip over-voltage circuitry. This simplifies equipment design and error analysis and results in more consistent output readings in industrial process controls, battery-powered instrumentation, power supply control and protection systems and remote sensors.

By providing localized signal conditioning and the industry’s best combination of low offset, low offset drift and wide gain-bandwidth, the ADA4091-2 delivers precision performance across a variety of sensor inputs, while the over-voltage protection feature prevents phase-inversion errors and excessive input current flows during transient or fault conditions. The performance of competing op amps must be evaluated to compensate for the error effects of discrete over-voltage circuitry on system performance, which adds a layer of complexity and uncertainty to the design process.

By integrating the requisite over-voltage protection circuitry, the ADA4091-2 dual micro-power op amp with rail-to-rail inputs and output allows system designers to reduce the number of external components needed to ensure stable system operation.

The new 1.5-MHz op amp features a low 350-µA-per-channel supply current, a 0.5-V/µs slew rate, and offset voltage of 500 µV max., which assure system accuracy with varied sensor types in harsh operating environments while eliminating the need for cooling fans or other costly thermal management devices. The 36-V ADA4091-2 op amp protects up to 12 V above and below the supply rails at ±15 V and 25 V above and below the supply rails at ±5 V. In an industrial signal chain, the ADA4091-2 is well matched to operate with a range of ADCs (analog-to-digital converters), including ADI’s AD761x and AD763x PulSAR® ADCs and AD7190 and AD7794 sigma-delta ADCs.

Availability and Pricing
The ADA4091-2 is sampling now and will be available in production quantities in November. The ADA4091-2 is housed in an 8-lead LFCSP (lead-frame chip-scale package) and is priced at $1.80 per unit in 1,000-unit quantities. For more information, visit

Analog Devices and Amplifiers
Analog Devices is a world leader in the design and manufacture of amplifiers. Amplifiers along with data converters are the foundation of the company. ADI is recognized by designers as offering the industry’s highest performance and most reliable high-speed, precision, RF, broadband, and instrumentation amplifiers. ADI also offers an extensive portfolio of comparators that are used in a wide variety of applications. For more information, visit

About Analog Devices

Innovation, performance, and excellence are the cultural pillars on which Analog Devices has built one of the longest standing, highest growth companies within the technology sector. Acknowledged industry-wide as the world leader in data conversion and signal conditioning technology, Analog Devices serves over 100,000 customers, representing virtually all types of electronic equipment. Analog Devices is headquartered in Norwood, Massachusetts, with design and manufacturing facilities throughout the world. Analog Devices is included in the S&P 500 Index.

PulSAR is a registered trademark of Analog Devices, Inc.

Editor's Contact Information:

Bob Olson

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