Instrumentation amplifier runs
down to 1.8V
Analog Devices has released the industry's first instrumentation amplifier to offer high precision at voltages as low as 1.8V
Analog Devices has released the industry's first instrumentation amplifier (in-amp) to offer high precision at voltages as low as 1.8V. Because previous generations of in-amps operated only as low as 2.7V, 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.
Optimised 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.
'The growing at-home medical monitoring market is driving the demand for high precision, portable products that operate at voltages as low as 1.8V', said Steve Sockolov, Product Line Director for Precision Amplifiers at Analog Devices.
'With the introduction of the AD8553, ADI is extending the company's proven expertise in developing highly accurate, low-noise in-amps to +1.8V applications'.
'Prior to the AD8553, lower voltage systems could only achieve high levels of precision performance by using discrete solutions that required additional trimming, consumed more board space, and were extremely costly and difficult to implement'.
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 1.8V targets portable medical devices, particularly those intended for at-home, noninvasive 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 gauges, 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 basestation control systems.
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 to +5.5V.
In shutdown mode, the total supply current is reduced to less than 4uA.
With low offset voltage of 25uV maximum, offset voltage drift of 0.1uV/C maximum and voltage noise of only 0.7uV peak-peak (0.1 to 10Hz), 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 at least 120dB min at a gain of 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 convertors, such as ADI's AD7466, AD7687 and AD7942.
Fully specified over the industrial temperature range of -40 to +85C, the AD8553 is sampling now with production quantities available in September 2005.
The device is packaged in 10-lead MSOPs and is priced at $1.30 per unit in 1000-piece quantities.
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