AD8646ARZ

Overview

The AD8646ARZ is a dual-channel, precision CMOS operational amplifier manufactured by Analog Devices. It features rail-to-rail input and output capabilities with a gain bandwidth product of 24 MHz and a slew rate of 11 V/µs. The device operates on a single supply voltage ranging from 2.7 V to 5.5 V, drawing a maximum supply current of 2 mA per amplifier. Key electrical characteristics include a maximum offset voltage of 2.5 mV, an input bias current of 1 pA, and a short-circuit output current of ±120 mA. It is housed in an 8-lead SOIC package and supports an operating temperature range from -40°C to +125°C.

Feature Summary

• Rail-to-rail input and output operation enables full signal swing across the entire supply voltage range.
• Low input bias current of 1 pA minimizes loading effects on high-impedance signal sources.
• High output drive capability provides up to 120 mA short-circuit current for low-impedance loads.
• Unity gain stability ensures reliable performance without external compensation components.

Applications

• Battery-powered instruments
• Multipole filters
• ADC front ends
• Photodiode amplifiers

Procurement Notes

Verify that the specific part number matches the required package type and temperature rating. Confirm RoHS compliance status as indicated by the suffix. Ensure the ordering quantity aligns with the manufacturer's standard packaging options. Cross-reference the datasheet revision to confirm all specifications match the design requirements before finalizing procurement.

Selection Notes

Select this component when a dual-channel amplifier with rail-to-rail I/O is required for single-supply systems. Consider the 24 MHz bandwidth and low noise density for AC applications. Evaluate the 1 pA input bias current suitability for high-impedance sensor interfaces. Verify that the 2.7 V minimum supply voltage meets the system power constraints.

Part Context

The AD8646ARZ belongs to the AD8646/AD8647/AD8648 family of precision amplifiers. While the AD8647 includes a shutdown feature and the AD8648 offers four channels, the AD8646 specifically provides two channels without shutdown functionality. All variants share similar core electrical characteristics, including bandwidth, noise, and offset voltage specifications.

Replacement Considerations

The AD8646ARMZ serves as a direct pin-compatible replacement using an MSOP-8 package instead of the SOIC-8. Both parts share identical electrical specifications and temperature ranges. Designers must verify footprint compatibility during substitution.