AD8638ARJZ-REEL

Overview

The AD8638ARJZ-REEL is a single-channel, auto-zero operational amplifier manufactured by Analog Devices Inc. in a 5-lead SOT-23 surface-mount package. It operates on a single supply of 5 V to 16 V or dual supplies of ±2.5 V to ±8 V. Key electrical parameters include a maximum offset voltage of 9 μV, a typical gain bandwidth product of 1.5 MHz, and a maximum supply current of 1.3 mA per amplifier. The device features rail-to-rail output swing, low input bias current (40 pA max), and high common-mode rejection ratio (133 dB typical). It is specified for operation across an extended industrial temperature range from -40°C to +125°C.

Feature Summary

• Utilizes a patented auto-zeroing topology to achieve extremely low offset voltage and drift without requiring external capacitors.
• Provides rail-to-rail output swing to maximize signal-to-noise ratio within the available supply voltage range.
• Greatly reduces digital switching noise typically found in chopper-stabilized amplifiers through optimized internal architecture.

Applications

• Pressure and position sensors
• Strain gage amplifiers
• Medical instrumentation
• Thermocouple amplifiers

Procurement Notes

Verify that the ordering suffix REEL corresponds to the reel packaging format required for your assembly line. Confirm the specific pinout configuration matches the 5-lead SOT-23 layout defined in the datasheet. Ensure the component meets the RoHS compliance standards applicable to your manufacturing region before finalizing procurement.

Selection Notes

Select this component when high DC precision is required alongside low power consumption in a compact footprint. The SOT-23 package offers space savings compared to larger packages but exhibits slightly higher offset voltage drift than SOIC versions. Consider the 1.5 MHz bandwidth and slew rate for applications requiring moderate speed with high accuracy.

Part Context

The AD8638 is part of the AD8638/AD8639 family of wide bandwidth, auto-zero amplifiers featuring rail-to-rail output swing. While the AD8638 provides a single channel, the AD8639 variant offers dual channels in similar packages. Both share the same core technology designed to combine low cost with high accuracy and low noise.

Replacement Considerations

The AD8638ARZ serves as a direct functional replacement offering identical specifications in an 8-lead SOIC package. Verify that the target PCB footprint can accommodate the larger SOIC dimensions if substituting the SOT-23 version.

FAQ

Does the AD8638 require external capacitors for its auto-zero function?

No, the AD8638 utilizes an internal topology that eliminates the need for external capacitors to perform auto-zeroing.

What is the maximum input bias current specification?

The maximum input bias current is 40 pA at 25°C, though it may increase to 250 pA at the upper limit of the operating temperature range.