AD8639ACPZ-REEL

Overview

The AD8639ACPZ-REEL is a dual-channel, auto-zero operational amplifier manufactured by Analog Devices Inc. It features rail-to-rail output swing and operates on a single supply of 5 V to 16 V or dual supplies of ±2.5 V to ±8 V. Key electrical parameters include a maximum offset voltage of 9 μV, a maximum input bias current of 75 pA at 5 V operation, and a typical gain bandwidth product of 1.5 MHz. The device provides high common-mode rejection ratio (CMRR) and power supply rejection ratio (PSRR), with a maximum supply current of 1.3 mA per amplifier.

Feature Summary

• Utilizes a patented ping-pong auto-zero topology that combines chopping and auto-zeroing techniques to minimize low-frequency noise and digital switching artifacts without requiring external filtering capacitors.
• Delivers extremely low offset voltage and drift characteristics across the extended industrial temperature range, ensuring stable performance for precision measurement applications.
• Features rail-to-rail output capability that maximizes signal-to-noise ratio by utilizing the full available supply voltage range.

Applications

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

Procurement Notes

Verify the specific package variant against the datasheet ordering guide, as the AD8639 is available in multiple packages including MSOP, SOIC, and LFCSP. Confirm that the REEL suffix corresponds to the required tape and reel packaging format for automated assembly processes. Ensure compatibility with the intended operating temperature range and supply voltage specifications before finalizing procurement.

Selection Notes

Select this component when high DC precision is required alongside low noise performance in space-constrained designs. The dual-channel configuration allows for cost-effective implementation of differential signal conditioning circuits. Consider the 1.5 MHz bandwidth and slew rate for applications requiring moderate speed, while leveraging the auto-zero feature to eliminate the need for manual calibration over temperature variations.

Part Context

The AD8639 belongs to the AD8638/AD8639 family of wide bandwidth, auto-zero amplifiers from Analog Devices. This series is designed to provide the benefits of expensive zero-drift amplifiers at a lower cost. The dual-channel AD8639 complements the single-channel AD8638, offering integrated solutions for multi-channel sensor interfaces within the same automotive-grade and industrial-grade portfolio.

Replacement Considerations

Direct functional replacements within the same family include the AD8638 for single-channel applications. For different channel counts, consider the AD8629 (dual, lower voltage) or AD8630 (quad). Verify pinout compatibility if substituting between package types such as MSOP, SOIC, or LFCSP variants.

FAQ

Does the AD8639 require external capacitors for its auto-zero function?

No, the AD8639 utilizes an internal patented topology that eliminates the need for external capacitors for auto-zeroing or chopping functions.

What is the input voltage range limitation for the AD8639?

The AD8639 is not rail-to-rail input; inputs must be maintained within the specified common-mode range, typically requiring at least 2 V below the positive supply rail to prevent output phase reversal.