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Cmos Voltage Comparator Touts 50,000:1 Improvement In Sensor Input Signal Detection

Unrivaled design breakthrough enables application of next generation sensor technology
SUNNYVALE, CA October 20, 2004 - Advanced Linear Devices, Inc. (ALD), the design innovation leader in analog semiconductors, announces today an ultra-sensitive, high-performance EPAD® analog voltage comparator. Designated the ALD2321, the first in this family of products is destined to revolutionize the field of small signal detection for practical sensor applications in defense, security, process control and a wide range of other industries.

Designed to reduce input loading effects that cause linearity errors and typically limit the resolution and sensitivity of many critical sensors, ALD's Voltage Comparator features a unique front-end stage with an input-signal power specification of only 0.004 pW (0.2 mV x 20 pA). Compared to current technology, which ranges from 200 - 1000 pW, circuit designers can realize a 50,000:1 improvement in small signal threshold detection, thereby expanding the useful range of many existing and new analog sensors that generate very low, sub-millivolt output signals.

The low input power design is achieved through the use of EPAD® Technology for electronically minimizing the input offset voltage and high impedance, insulated gate MOSFET transistors, which subsequently drive the input amplifier stage by controlling the input gate voltage. Other pertinent features include low power supply current - 110µA, 3 to 11 Vdc power supply, dual complementary (push-pull) outputs, 50mA output sink current, and 30 TTL load fanout.

For mission-critical applications that depend on highly advanced sensors with signals that are difficult to detect, ALD delivers the only voltage comparator capable of providing the signal detection to complete the mission. This makes them ideal for sensitive instrumentation in mobile platforms and the increasing need to detect trace molecular amounts of chemical, biological and radioactive elements. Other applications include power supply voltage monitors, photodiode sensors, and relay or LED drivers.
As sensors have become more sophisticated, signal amplification is usually required to take advantage of their full output range.

Historically, sensor advancements have exceeded the capacity of supporting analog circuitry to render the full range of their sensitivity unattainable - until now. ALD has reinvented the analog voltage comparator to capture and process the faintest signals for high performance applications. Signals that previously required preprocessing and amplification can now be directly processed by ALD voltage comparators.

"ALD has taken a standard component and turbo-charged it to make it a state-of-the-art analog device," said Robert L. Chao, President and CEO of Advanced Linear Devices. "By doing so, ALD has taken a fresh look at the basic functions that these devices perform and breathed new life into them, enabling voltage comparators to meet the wide range of signal detection demands from a new generation of sensors."

Although voltage comparators aren't new technology, ALD has taken a creative approach to improving these important analog components. ALD has embedded several discrete functions into a single CMOS chip - the resulting circuit is unmatched in its precision. The ALD dual voltage comparator simultaneously delivers the lowest input bias current and lowest input/offset voltage available in a single chip. The chip supports applications demanding low level signal detection with high source impedance. The ALD2321 EPAD Voltage Comparator is available now in sample quantities from Mouser Electronics. Pricing is $3.06 - $4.57 depending on the grade required.

About EPAD®
EPAD® is an acronym for Electrically Programmable Analog Device - a patented and trademarked technology developed by ALD to precisely trim a variety of CMOS analog integrated circuit elements at the die or packaged level. EPAD® is a proven design and manufacturing technology first conceived by ALD almost twenty years ago. This technology has been steadily improved over the years. Once trimmed, the device voltage and current characteristics are stored indefinitely in the chip even when the power to the chip is removed. Programming or trimming is achieved through a series of software controlled voltage bursts to a floating gate structure.

About E-TRIM™
E-trim is an automated ALD developed process for fine tuning MOSFET circuit elements using EPAD technology. These MOSFET elements are integrated on ALD2321 dual voltage comparators for trimming the input offset voltage (Vos). At near completion of the manufacturing cycle, this MOSFET device(s) is called upon to perform a computer-automated calibration, or "e-trim". At that point, any accrued residue device errors are measured and corrected to specification.

About Advanced Linear Devices, Inc. Advanced Linear Devices, Inc. (ALD) is a design innovation leader in analog semiconductors specializing in the development and manufacture of precision CMOS linear integrated circuits, including analog switches, A/D converters and chipsets, voltage comparators, operational amplifiers, analog timers, and conventional and EPAD MOSFET transistors. Most standard functions are also available as ASIC cells for the development of customized integrated circuits.

ALD was founded in 1985 with a commitment to bridge the technology gaps by providing analog semiconductor solutions to the challenges facing OEM design engineers in the industrial controls, military, automotive, security, and medical instrumentation markets. ALD is headquartered in Sunnyvale, CA. with distributors throughout the U.S. and Europe.
Download Data Sheet ALD2321A/ALD2321B/ALD2321