New Analog Devices Instrumentation Amplifier Delivers Precision Performance To Low-Voltage Applications

Analog Devices AD8553

Unmatched combination of high accuracy, low noise, and low price makes ADI's AD8553 in-amp ideal for portable medical devices and low-voltage industrial and communications applications.

Analog Devices Inc. has released the industry's first instrumentation amplifier (in-amp) to offer high precision at voltages as low as 1.8 V. Because previous generations of in-amps operated only as low as 2.7 V, many ultra low-voltage applications, such as medical monitoring devices, could not benefit from the combination of precision performance, low-noise operation and reduced pricing offered by in-amps. For applications where precision is crucial, in-amps magnify small signals while rejecting large amounts of noise that can interfere with the accuracy of measurements. Optimized for a broad range of industrial, communications and medical applications that require low-voltage operation, the AD8553 provides significant performance advantages at half the price of competing solutions.
AD8553 instrumentation amplifier
Medical, Industrial and Communications Applications
The AD8553 provides superior performance to a variety of low-voltage medical, industrial and communications applications. A power-saving shutdown mode that extends battery life combined with low-noise operation at 1.8 V targets portable medical devices, particularly those intended for at-home, non-invasive patient use such as blood pressure and glucose monitors. High-performance hospital equipment such as electrocardiogram monitors and defibrillators, and industrial applications such as strain gages, weigh scales, and pressure sensors benefit from the high precision and high CMRR (common mode rejection ratio). The AD8553's high dc accuracy is also of benefit to low-side current sensing and other monitoring functions in communications base station control systems.

About the AD8553
The AD8553 precision in-amp features very high CMRR even at low gains, low offset and low offset drift for the highest dc accuracy, low-noise operation and low-voltage operation from +1.8 V to +5.5 V. In shutdown mode, the total supply current is reduced to less than 4 microamps.

With low offset voltage of 25 microvolts max, offset voltage drift of 0.1 microvolts/degrees C max and voltage noise of only 0.7 microvolts p-p (0.1 Hz to 10 Hz), the AD8553 is ideal for applications where error sources cannot be tolerated. Unlike many in-amps, parasitic resistance in series with the Vref pin does not degrade performance, allowing the AD8553 to attain very high CMRR performance of 120 dB min at G=100 without using a buffer amplifier to drive the Vref pin. The rail-to-rail output of the AD8553 makes it ideal for driving and buffering converters, such as ADI's AD7466, AD7687 and AD7942.

Pricing and Availability
Fully specified over the industrial temperature range of -40 degrees C to +85 degrees C, the AD8553 is sampling now with production quantities available in September 2005. The device is packaged in 10-lead MSOP and is priced at $1.30 per unit in 1,000-piece quantities.