AD8627AKS-R2

Overview

The AD8627AKS-R2 is a precision, low-power, single-supply JFET input operational amplifier from Analog Devices. It features rail-to-rail output capability and operates on supply voltages ranging from 5 V to 26 V (single) or ±2.5 V to ±13 V (dual). Key electrical specifications include a maximum offset voltage of 0.5 mV at 25°C, a typical supply current of 630 μA per amplifier, and a gain-bandwidth product of 5 MHz. The device maintains unity gain stability and exhibits no phase reversal near the positive rail. It is housed in a compact 5-lead SC70 surface-mount package.

Feature Summary

• JFET input stage providing ultra-low input bias current for minimal signal loading
• Rail-to-rail output swing maximizing dynamic range in single-supply systems
• True single-supply operation with input common-mode range extending below the negative rail
• Unity gain stable design ensuring robust performance in buffer configurations

Applications

• Photodiode transimpedance amplifiers requiring picoampere-level input currents
• Precision active filters utilizing high-value resistors due to low bias current
• Buffer stages for CMOS DACs and ASICs requiring wide output swing
• Battery-powered instrumentation and portable sensor signal conditioning

Procurement Notes

Verify the specific ordering suffix KS-R2 corresponds to the 5-lead SC70 package configuration. Confirm that the component is supplied in tape and reel format as specified for this package type. Ensure the industrial temperature range rating aligns with your system's environmental requirements. Cross-reference the datasheet revision to confirm all electrical characteristics match your design constraints before finalizing procurement.

Selection Notes

Select this component when low input bias current is critical to minimize errors in high-impedance source applications. The rail-to-rail output allows for maximum signal swing in single-supply environments where traditional op-amps lose headroom. Consider the 5 MHz bandwidth and 5 V/μs slew rate for applications requiring moderate speed. Verify that the 630 μA supply current meets power budget constraints compared to higher-performance but more power-hungry alternatives.

Part Context

The AD8627 is part of the AD862x family, which includes the dual-channel AD8626 and quad-channel AD8625 variants. All members share identical electrical characteristics, including the JFET input stage, low offset voltage, and rail-to-rail output capabilities. The primary distinction lies in the number of amplifiers per package and the available package types, such as SOIC, MSOP, TSSOP, and SC70, allowing designers to optimize board space and channel count.

Replacement Considerations

Direct functional substitutes within the same family include the AD8626 and AD8625, provided the additional channels are acceptable. For pin-compatible replacements in the SC70 package, verify if other manufacturers offer JFET-input op-amps with similar bias current and offset specifications. Ensure any replacement maintains the rail-to-rail output characteristic and single-supply compatibility required by the original design.

FAQ

Does the AD8627 experience phase reversal when input signals approach the positive supply rail?

No, the AD8627 does not experience phase reversal with input signals close to the positive rail, unlike some older single-supply JFET amplifiers.

How does junction temperature affect the input bias current of the AD8627?

Like other JFET input amplifiers, the input bias current of the AD8627 doubles for every 10°C rise in junction temperature.

What is the input common-mode voltage range relative to the supply rails?

The input common-mode voltage extends from 0.2 V below the negative rail (–VS) to 2 V below the positive rail (+VS).