AD8639ARMZ-REEL

Overview

The AD8639ARMZ-REEL is a dual-channel, wide bandwidth, auto-zero operational amplifier manufactured by Analog Devices Inc. It features rail-to-rail output swing and low noise characteristics with a maximum supply voltage of 16 V. The device operates on single supplies from 5 V to 16 V or dual supplies from ±2.5 V to ±8 V. Key electrical parameters include a typical offset voltage of 3 μV, an input bias current of 75 pA at 16 V, and a gain-bandwidth product of 1.5 MHz. It provides high common-mode rejection ratio (CMRR) and power supply rejection ratio (PSRR), ensuring precision in demanding environments.

Feature Summary

• Utilizes a patented ping-pong auto-zero topology that combines chopping and auto-zeroing to minimize digital switching noise without requiring external filtering capacitors.
• Delivers extremely low offset voltage and drift across the extended industrial temperature range, maintaining high accuracy over time and thermal variations.
• Features rail-to-rail output capability to maximize signal-to-noise ratio and system dynamic range within the available supply voltage limits.

Applications

• Pressure and position sensors
• Strain gage amplifiers
• Medical instrumentation
• Thermocouple amplifiers
• Automotive sensors

Procurement Notes

Verify the specific REEL suffix against the manufacturer's official ordering guide to confirm package type and tape-and-reel specifications. Ensure compatibility with surface-mount assembly processes for the MSOP-8 footprint. Confirm automotive qualification status if required for the target application environment.

Selection Notes

Select this component when high DC precision and low drift are critical requirements. The dual-channel configuration allows for cost-effective implementation of differential sensing circuits. Consider the 1.5 MHz bandwidth for applications requiring moderate speed alongside ultra-low offset performance.

Part Context

The AD8639 is part of the AD8638/AD8639 family of auto-zero amplifiers designed for high-precision applications. It serves as the dual-channel counterpart to the single-channel AD8638. Both devices share identical electrical characteristics but differ in channel count and physical packaging options.

Replacement Considerations

Direct functional equivalents within the same series include the AD8638 for single-channel applications. Other packages such as SOIC or LFCSP may be used if pinout compatibility is verified through the manufacturer's outline dimensions.

FAQ

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

No, the AD8639 utilizes an internal auto-zero topology that does not require external capacitors for operation.

What is the input voltage range limitation for the AD8639?

The inputs are not rail-to-rail; they must remain within the specified common-mode voltage range, typically requiring at least 2 V headroom below the positive supply to prevent output phase reversal.