AD8642ARMZ

Overview

The AD8642ARMZ is a dual-channel, low-power precision JFET input operational amplifier manufactured by Analog Devices Inc. It features rail-to-rail output capability and operates within an extended industrial temperature range of -40°C to +125°C. Key electrical specifications include a maximum supply current of 250 µA per amplifier, a maximum input bias current of 1 pA, and a maximum offset voltage of 750 µV. The device supports single-supply operation from 5 V to 26 V or dual-supply operation from ±2.5 V to ±13 V. It exhibits a gain-bandwidth product of 3 MHz, a slew rate of 2 V/µs at 5 V supply, and unity-gain stability without phase reversal.

Feature Summary

• Features extremely low input bias current suitable for high-impedance signal sources
• Provides rail-to-rail output swing in single-supply systems
• Maintains stability with capacitive loads exceeding 500 pF
• Operates without phase reversal across the full common-mode voltage range

Applications

• Photodiode amplifiers
• Precision current sensing
• Medical instrumentation
• Battery-powered instruments
• Portable audio equipment

Procurement Notes

Verify the package type matches the required footprint, as the AD8642 series includes SOIC and MSOP variants. Confirm RoHS compliance status indicated by the 'Z' suffix. Ensure the ordering suffix corresponds to the desired tape-and-reel quantity if applicable. Cross-reference the specific part number against the manufacturer's official ordering guide to validate availability and exact pinout configuration.

Selection Notes

Select this component when low power consumption and high DC precision are critical requirements. The JFET input stage minimizes loading effects on high-impedance sensors. Consider the MSOP package for space-constrained designs requiring surface-mount assembly. Evaluate thermal resistance characteristics if operating near the upper temperature limits.

Part Context

The AD8642ARMZ belongs to the AD8641/AD8642/AD8643 family of low-power, precision JFET amplifiers. While sharing core electrical performance characteristics such as low bias current and rail-to-rail output, the AD8642 specifically provides two channels in an 8-lead Mini Small Outline Package (MSOP). This distinguishes it from the single-channel AD8641 and the quad-channel AD8643.

Replacement Considerations

The AD8642ARZ serves as a direct functional replacement offering identical electrical specifications but utilizes an 8-lead Standard Small Outline Package (SOIC) instead of the MSOP form factor.