Analog Devices Inc. AD8223BRZ

Overview

AD8223BRZ from Analog Devices is a single-supply, rail-to-rail output instrumentation amplifier optimized for low-power, precision signal conditioning in battery-powered and industrial systems. It delivers gain of 5–1000 set by one external resistor, features 30 nV/√Hz input-referred voltage noise at G=1000, 25 nA max input bias current, and operates from 3 V to 24 V single supply or ±2 V to ±12 V dual supply. It is used in thermocouple amplification and transducer interface circuits where input signals extend 150 mV below ground.

For engineers reviewing the AD8223BRZ datasheet, AD8223BRZ pinout, AD8223BRZ application, or AD8223BRZ equivalent, this page provides verified technical context, exact pin functions, real-world application mappings, and two confirmed alternative parts with documented functional trade-offs for medical, industrial, and data acquisition designs.

Technical Context

The AD8223BRZ implements a modified 3-op-amp architecture with PNP input buffers enabling input common-mode voltage down to 150 mV below the negative rail. Its gain stage uses an external resistor (RG) across pins 1 and 8 to set total gain per G = 5 + (80 kΩ/RG), while the third-stage differential amplifier provides fixed ×5 gain and removes common-mode content.

It supports rail-to-rail output swing on single supply (e.g., +0.01 V to +VS − 0.5 V at 10 kΩ load), achieves CMRR ≥90 dB at G=100/1000 (DC–60 Hz), and maintains 125 kHz small-signal bandwidth at G=5 under +5 V supply. Input impedance is 2 GΩ || 2 pF differential and common-mode.

Key Specifications

Pinout & Package

AD8223BRZ is packaged in an 8-lead SOIC (R) with standard industry pinout. Thermal resistance θJA = 155°C/W. RoHS-compliant, Pb-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8223BRZ, AD8221ARMZ offers higher DC accuracy but sacrifices single-supply simplicity and power efficiency, while INA333AIDR improves drift and noise at the cost of input common-mode flexibility - making AD8223BRZ the optimal balance for battery-powered transducer interfaces requiring sub-ground signal handling.

Availability

AD8223BRZ is available at Aetrix Electronics and suitable for thermocouple amplification, industrial transducer interface, and portable medical instrumentation requiring stable component supply, full production traceability, and long-term lifecycle support.

Supply support for AD8223BRZ 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 leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD8223 belongs to Analog Devices' precision instrumentation amplifier product line, designed specifically for low-power, single-supply signal conditioning in sensor front-ends where rail-to-rail output and sub-ground input capability are essential.

FAQ

What is the minimum supply voltage for AD8223BRZ in single-supply operation?

The AD8223BRZ supports single-supply operation from +3 V to +24 V. At +3 V, it delivers rail-to-rail output swing (≥0.01 V to +2.5 V at 10 kΩ), 500 μA quiescent current, and maintains full gain accuracy and CMRR performance. Operation below +3 V is not characterized and may result in degraded output swing or increased distortion.

Can AD8223BRZ amplify signals with common-mode voltage below ground?

Yes, the AD8223BRZ accepts input common-mode voltages down to (−VS) − 0.15 V. In single-supply mode with −VS = 0 V, this means it can amplify signals with common-mode as low as −150 mV - enabling direct connection of grounded thermocouples and bridge sensors without external level-shifting circuitry.

How is gain set on AD8223BRZ, and what resistor value gives G=100?

Gain is set by an external resistor RG connected between pins 1 (−RG) and 8 (+RG). The relationship is G = 5 + (80 kΩ / RG). For G=100, RG = 845 Ω (standard 1% value yields G=99.7). No resistor yields default G=5, relying solely on internal laser-trimmed resistors for minimal drift and error.

What is the maximum capacitive load AD8223BRZ can drive without instability?

The AD8223BRZ is specified to drive ≥10 kΩ resistive loads. For capacitive loads, stability degrades above ~100 pF. When driving cables or ADC input capacitance, a series isolation resistor (e.g., 75 Ω) between OUT and the load is recommended to prevent peaking and overshoot - empirically validated in Figure 26 and Figure 27 of the datasheet.

Does AD8223BRZ require external protection diodes on its inputs?

No. The AD8223BRZ includes internal supply-referenced clamping diodes on all pins (inputs, REF, OUT, RG), allowing safe operation with overvoltages up to ±0.3 V beyond the supply rails - both during power-on/off and normal operation. External current-limiting resistors are only needed if overvoltage exceeds ±0.3 V or fault current may exceed 10 mA.