Current-sense Amplifier Combines Zero Drift and High Bandwidth

Analog Devices’ AD8218 offers users a flexible, high voltage, zero-drift current-sense amplifier that features industry-leading performance and value.

NORWOOD, Mass – March 9, 2011 - Analog Devices, Inc. (ADI) released for general availability today the newest addition to its popular current-sense-amplifier product line. The AD8218 zero-drift, bi-directional current-sense amplifier offers design engineers a precision current-sense amplifier with the unique combination of high bandwidth and the lowest drift currently available in the market in a low-cost package. Using a proprietary CMOS process, the AD8218 features a zero-drift core that provides an offset drift of ± 100n V/°C over a −40 °C to +125 °C temperature range, while maintaining a typical small signal bandwidth of 500 kHz.

• Download data sheets and view product pages: http://www.analog.com/AD8218
• Order samples: http://www.analog.com/AD8218
• Learn more about high-side current sensing with wide dynamic range: http://www.analog.com/library/analogdialogue/archives/44-12/high_side.pdf
• Find application notes and technical articles about wireless and communications solutions from ADI: http://communications.analog.com/en/segment/cmmn.html

ADI’s newest zero-drift current-sense amplifier has a 20 V/V fixed gain with a maximum ±0.35 percent gain error over the entire temperature range. The AD8218 zero-drift precision amplifier’s input common-mode can vary from 4 V to 80 V and includes a built-in reference for optimal dynamic range in unidirectional current monitoring or the ability to easily offset the output for bidirectional current sensing.

Designed to operate with a wide variety of A/D converters, the AD8218 is designed into numerous high-side current-sensing signal chains, including base station, industrial motor control and computer power management applications. Other precision zero-drift current sense amplifiers in the product family include the AD8217 high resolution, zero-drift current shunt monitor at http://www.analog.com/AD8217 and the AD8219 zero-drift, unidirectional current shunt monitor at http://www.analog.com/AD8219.

AD8218 Zero Drift, Bi-directional Current-Sense Amplifier Key Features

• High common-mode voltage range

• 4 V to 80 V operating
• -0.3 V to 85 V survival

• Buffered output voltage
• Gain = 20 V/V (60 V/V AD8219)
• Wide operating temperature range: −40 °C to +125 °C
• Excellent ac and dc performance

• ±100 nV/°C typical offset drift
• ±50 μV typical offset
• ±5 ppm/°C typical gain drift

• 110 dB typical CMRR at dc

Availability, Pricing and Complementary Components

Complementary components, particularly in base station applications include the ADCMP371 general-purpose comparators, ADUC7026 precision analog micro-controller and ADCMP600 TTL/CMOS comparator