AD8642ARZ

Overview

The AD8642ARZ is a dual-channel, low-power precision JFET operational amplifier manufactured by Analog Devices Inc. It features rail-to-rail output capability and operates on single supplies from 5 V to 26 V or dual supplies from ±2.5 V to ±13 V. The device offers 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. It provides a gain bandwidth product of 3 MHz and a slew rate of 2 V/μs at 5 V, or 3.5 MHz and 3 V/μs at ±13 V. The component is housed in an 8-lead SOIC package and functions within an extended industrial temperature range of −40°C to +125°C.

Feature Summary

• JFET input architecture providing extremely low input bias current for high impedance signal interfacing.
• Rail-to-rail output stage enabling full dynamic range utilization in single-supply systems.
• Unity-gain stability with no phase reversal when driven beyond the common-mode input range.
• Capacitive load drive capability supporting loads exceeding 500 pF without oscillation.

Applications

• Photodiode amplifiers
• Precision current sensing
• Line- or battery-powered instruments
• Medical instrumentation
• Industrial controls

Procurement Notes

Verify that the ordering suffix ARZ corresponds to the 8-lead Standard Small Outline Package (R-8) configuration. Confirm RoHS compliance status indicated by the Z suffix. Ensure the procurement specification matches the required operating temperature range of −40°C to +125°C. Validate pinout alignment against the specific datasheet revision prior to PCB layout finalization.

Selection Notes

Select this component for applications requiring low power consumption alongside high DC precision. The JFET input stage is optimal for sources with high output impedance. Verify that the required gain bandwidth product and slew rate meet the AC performance specifications of the target circuit design.

Part Context

This part belongs to the AD864x family of low power, rail-to-rail output, precision JFET amplifiers. The AD8642 variant specifically integrates two independent amplifier channels within a single package. The family shares core electrical characteristics including low offset voltage and low noise density, differentiated primarily by channel count and available package options.

Replacement Considerations

AD8642ARMZ: Dual-channel version in 8-lead MSOP package.

FAQ

Does the AD8642ARZ exhibit phase reversal when the input voltage exceeds the supply rails?

No, the device is designed with no phase reversal characteristics even when driven beyond the common-mode input range.

What is the maximum capacitive load the AD8642ARZ can drive stably?

The outputs remain stable with capacitive loads of more than 500 pF.