AD8639ARZ-REEL7

Overview

The AD8639ARZ-REEL7 is a dual-channel, wide-bandwidth auto-zero operational amplifier manufactured by Analog Devices Inc. It features rail-to-rail output swing and operates on single supplies from 5 V to 16 V or dual supplies from ±2.5 V to ±8 V. The device achieves high precision with a maximum offset voltage of 9 μV and an offset drift of 0.04 μV/°C. Key electrical parameters include a gain bandwidth product of 1.5 MHz, a slew rate of 2 V/μs at 16 V, and a supply current of 1.3 mA per amplifier. It offers a typical CMRR of 133 dB and PSRR of 143 dB.

Feature Summary

• Utilizes a patented ping-pong auto-zero topology that combines chopping and auto-zeroing to minimize low-frequency noise and digital switching artifacts without requiring external filtering capacitors.
• Provides rail-to-rail output swing capability, allowing the signal to utilize the full dynamic range between the power supply rails to maximize signal-to-noise ratio.
• Delivers ultrahigh DC precision through extremely low input offset voltage and minimal temperature drift across the extended industrial operating range.

Applications

• Pressure and position sensors
• Strain gage amplifiers
• Medical instrumentation
• Thermocouple amplifiers
• Precision current sensing

Procurement Notes

Verify the specific package type against the ordering suffix, as the AD8639 series includes MSOP, SOIC, and LFCSP variants. Confirm the automotive qualification status if required for your application, as standard and qualified versions may differ. Ensure the reel quantity matches your production needs and check for moisture sensitivity level requirements during storage and handling.

Selection Notes

Select this component when high DC accuracy and low drift are critical but cost constraints prohibit expensive chopper-stabilized alternatives. It is suitable for applications requiring wide bandwidth combined with zero-drift performance. Consider the input voltage range limitations; it is not rail-to-rail input, so ensure signals stay within specified common-mode limits to prevent phase reversal.

Part Context

This part belongs to the AD8638/AD8639 family of auto-zero amplifiers. While the AD8638 is a single-channel version, the AD8639 provides two channels in one package. The 'ARZ' suffix typically denotes the 8-lead SOIC package variant, distinguishing it from other physical form factors available within the same functional family.

Replacement Considerations

Direct replacements within the same family include the AD8638 for single-channel applications. For different packages, verify pin compatibility with other AD8639 variants such as the MSOP or LFCSP versions before substitution.

FAQ

Does the AD8639 feature rail-to-rail inputs?

No, the AD8639 does not have rail-to-rail inputs. Care must be taken to ensure the input common-mode voltage remains within the specified range to avoid output phase reversal.

How does the auto-zero topology affect noise performance?

The patented ping-pong arrangement reduces both low-frequency 1/f noise and the noise energy at the chopping frequency, providing a wide noise-free bandwidth without the need for additional external filtering.