Analog Devices Inc. AD622ANZ

Overview

AD622ANZ from Analog Devices is a low-cost, monolithic instrumentation amplifier with unity-gain capability and programmable gain (2–1000) via a single external resistor. It features 125 µV max input offset voltage, 800 kHz bandwidth at G=10, 1.2 V/µs slew rate, and operates from ±2.6 V to ±15 V supplies. It is used in transducer interface circuits requiring high common-mode rejection and stable DC performance.

For engineers reviewing the AD622ANZ datasheet, AD622ANZ pinout, AD622ANZ application, or AD622ANZ equivalent, key selection criteria include gain accuracy (0.15% at G=1), input bias current (5 nA max), RTI noise (0.6 µV p-p, 0.1–10 Hz, G=10), CMRR (98 dB at G=10), and PDIP-8 package compatibility with legacy layouts.

Technical Context

The AD622ANZ implements a modified three-op-amp architecture with laser-trimmed internal 25.25 kΩ gain resistors, enabling precise gain setting via RG between Pins 1 and 8. Its bipolar input stage (Q1/Q2) delivers low input bias current and stable offset drift (1.0 µV/°C).

Gain is defined as G = 1 + (50.5 kΩ / RG); for G=1, RG is left open. The REF pin provides user-adjustable output offset, while internal protection tolerates ±60 mA input current - critical for industrial sensor interfaces with mismatched power domains.

Key Specifications

Pinout & Package

AD622ANZ is housed in an 8-lead plastic dual in-line package (PDIP, N-8), compliant with JEDEC MS-001, with 0.300-inch body width and 0.100-inch lead pitch. Thermal resistance θ_JA = 95°C/W in free air.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar instrumentation amplifier applications.

Compared with AD8221ARZ and AD8226ARMZ, the AD622ANZ offers the best balance of cost, ease of use (unity-gain no-resistor operation), and industrial-grade ruggedness - including ±60 mA input fault tolerance and PDIP-8 availability for serviceability - without sacrificing essential DC and AC performance for mainstream process monitoring.

Availability

AD622ANZ is available at Aetrix Electronics and suitable for industrial process controls, transducer interface modules, and low-cost data acquisition systems requiring stable component supply across extended temperature ranges (–40°C to +85°C) and long production lifecycles.

Supply support for AD622ANZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The AD622ANZ belongs to Analog Devices' instrumentation amplifier product line, engineered for cost-sensitive industrial and sensor interface applications where reliability, ease of design-in, and proven performance outweigh ultra-high-precision requirements.

FAQ

What is the maximum gain achievable with AD622ANZ, and how is it set?

The AD622ANZ supports gains from 1 to 1000. Gain = 1 requires no external resistor (RG pins left open). For higher gains, a single resistor RG is connected between Pins 1 and 8, calculated as RG = 50.5 kΩ / (G − 1). At G = 1000, RG = 51.1 Ω yields nominal gain; the AD622ANZ datasheet specifies 0.50% max gain error under these conditions.

Does AD622ANZ require external capacitors for stability, and what layout practices improve its CMRR?

No external compensation capacitors are required for stability - the AD622ANZ is unity-gain stable. To maximize CMRR, match impedances seen by +IN and –IN pins (e.g., equal RFI filter resistors), use NPO/COG capacitors for input filtering, minimize parasitic resistance at the REF pin, and avoid ground loops by routing REF separately from power grounds. These practices directly preserve the AD622ANZ's specified 98 dB CMRR at G=10.

Can AD622ANZ operate from a single supply, and what are the input/output voltage limitations?

The AD622ANZ is specified for dual supplies only (±2.6 V to ±15 V); it is not characterized for true single-supply operation. Input common-mode range is –VS + 1.9 V to +VS – 1.2 V (e.g., –13.1 V to +13.8 V at ±15 V), and output swing is –VS + 1.2 V to +VS – 1.4 V into 10 kΩ. For single-rail systems, consider the AD8226 or AD8421 instead - the AD622ANZ requires symmetric rails for guaranteed specs.

How does the REF pin function in AD622ANZ, and what drive capability does it need?

The REF pin sets the output's zero-reference level: V_OUT = G × (V_+IN – V_–IN) + V_REF. It has 20 kΩ input resistance and accepts voltages from –VS + 1.6 V to +VS – 1.6 V. Because 50–60 µA flows into REF, it must be driven by a low-impedance source (e.g., op-amp buffer or precision DAC). Unbuffered connections cause gain-dependent offset errors - a key design consideration for accurate calibration in AD622ANZ-based systems.

Is AD622ANZ RoHS-compliant, and what is its package type and thermal performance?

Yes, AD622ANZ is RoHS-compliant (indicated by the "Z" suffix). It uses an 8-lead PDIP package (N-8) with JEDEC MS-001 outline. Its thermal resistance is θ_JA = 95°C/W in free air. This allows continuous operation at up to +85°C ambient when dissipating ≤650 mW - well within its 1.5 mA max supply current at ±15 V (22.5 mW typical dissipation), ensuring robust thermal margin in enclosed industrial enclosures.