ADA4638-1ARZ

Overview

The ADA4638-1ARZ is a single-channel, high-voltage precision zero-drift amplifier manufactured by Analog Devices Inc. in an 8-lead SOIC package. It operates from a single supply of 4.5 V to 30 V or dual supplies of ±2.25 V to ±15 V. Key electrical specifications include a maximum input offset voltage of 12.5 μV and a drift of 0.08 μV/°C over the extended industrial temperature range (-40°C to +125°C). The device features a gain-bandwidth product of 1.5 MHz, a slew rate of 1.5 V/μs, and a low supply current of 0.95 mA. It provides rail-to-rail output swing with high CMRR (142 dB) and PSRR (143 dB), ensuring minimal error from common-mode and power supply variations.

Feature Summary

• Utilizes a patented combination of auto-zeroing and chopping techniques to achieve ultralow offset voltage and negligible drift across wide temperature ranges.
• Features rail-to-rail output capability that maximizes signal-to-noise ratio while maintaining no output phase reversal within specified input limits.
• Provides high DC accuracy through exceptional common-mode rejection and power supply rejection ratios, correcting errors caused by voltage swings.

Applications

• Electronic weigh scales
• Pressure and position sensors
• Strain gage amplifiers
• Medical instrumentation
• Thermocouple amplifiers

Procurement Notes

Verify the specific ordering suffix ARZ confirms the 8-lead SOIC package variant when sourcing. Ensure the component meets RoHS compliance requirements for your assembly process. Confirm availability status directly with authorized distributors as stock levels fluctuate. Validate that the intended operating voltage range aligns with the 4.5 V to 30 V specification before finalizing procurement.

Selection Notes

Select this amplifier for applications requiring high DC precision without the need for external calibration due to its zero-drift architecture. It is suitable for systems needing rail-to-rail output swing to maximize dynamic range. Consider the 8-lead SOIC package for standard surface-mount assembly processes. Evaluate the 1.5 MHz bandwidth against your signal frequency requirements to ensure adequate performance.

Part Context

The ADA4638-1 belongs to Analog Devices' Zero-Drift Op Amp portfolio, designed for high-precision applications where large error sources are intolerable. It complements other devices like the AD8638 and ADA4528-1 but offers higher voltage operation up to 30 V. The family utilizes advanced modulation techniques to eliminate 1/f noise and offset drift, making it distinct from traditional chopper-stabilized amplifiers.

Replacement Considerations

Check datasheets for pin-compatible alternatives such as the ADA4638-1ACPZ if LFCSP packaging is required. Verify that substitute parts maintain similar offset voltage and drift specifications to ensure circuit accuracy is preserved.

FAQ

Does the ADA4638-1 exhibit output phase reversal?

No, the ADA4638-1 is designed to prevent output phase reversal provided that both inputs are maintained within the supply voltages.

What is the input common-mode voltage range?

The input common-mode voltage range includes the lower supply rail, allowing operation down to 0 V relative to the negative supply.