AD8629ARZ

Overview

The AD8629ARZ is a dual-channel, zero-drift operational amplifier featuring rail-to-rail input and output swing. It operates on a single supply from 2.7 V to 5 V or dual supplies of ±1.35 V to ±2.5 V. Key electrical parameters include a gain-bandwidth product of 2.5 MHz, a slew rate of 1 V/µs, and an input offset voltage of 1 µV. The device draws 1 mA of supply current per amplifier and provides a maximum output current of 30 mA. It exhibits low noise density of 22 nV/√Hz at 1 kHz and maintains high CMRR and PSRR of 130 dB.

Feature Summary

• Utilizes a patented combination of auto-zeroing and chopping techniques to achieve ultralow offset voltage and drift while minimizing digital switching noise.
• Features rail-to-rail input and output capabilities, allowing operation across the full supply range without phase reversal when inputs remain within rails.
• Provides extremely low input bias current and eliminates 1/f noise internally, ensuring high precision for DC-coupled measurements.

Applications

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

Procurement Notes

Verify the specific package variant against the ordering guide, as the AD8629 series includes MSOP and SOIC options with different suffixes. Confirm RoHS compliance status via the manufacturer's documentation. Ensure the selected part matches the required temperature range and automotive qualification if applicable to the design specifications.

Selection Notes

Select this component for applications requiring high DC precision with minimal external filtering due to low noise characteristics. Consider the 2.5 MHz bandwidth and fast overload recovery time for systems driving switched-capacitor ADCs. Verify that the supply voltage range aligns with the system's power constraints and that the SOIC-8 package fits the PCB layout requirements.

Part Context

The AD8629ARZ belongs to the AD8628/AD8629/AD8630 family of zero-drift amplifiers manufactured by Analog Devices. This series combines low cost with high accuracy, offering performance previously found only in expensive chopper-stabilized amplifiers. The AD8629 specifically provides two channels in an 8-lead narrow SOIC package, suitable for space-constrained designs requiring dual-channel signal conditioning.

Replacement Considerations

The AD8629ARMZ serves as a pin-compatible alternative in an 8-lead MSOP package. Automotive-grade variants such as the AD8629WARZ are available for qualified applications. Designers should verify that any substitute maintains the same zero-drift topology and electrical specifications to ensure circuit compatibility.