Analog Devices Inc. AD8223ARZ-R7

Overview

AD8223ARZ-R7 from Analog Devices is a single-supply, rail-to-rail output instrumentation amplifier with gain set by one external resistor (5–1000 V/V), 30 nV/√Hz input-referred voltage noise at 1 kHz (G = 1000), 25 nA max input bias current, and 500 μA max quiescent current. It operates from +3 V to +24 V single supply and supports low-power medical instrumentation and thermocouple amplification.

For engineers reviewing the AD8223ARZ-R7 datasheet, AD8223ARZ-R7 pinout, AD8223ARZ-R7 application, or AD8223ARZ-R7 equivalent, key selection criteria include its 150 mV below negative rail input common-mode range, ±0.1% gain error (G = 5), 125 kHz small-signal bandwidth (G = 5, single supply), and SOIC-8 package compatibility with industry-standard layouts.

Technical Context

The AD8223ARZ-R7 implements a modified 3-op-amp architecture with PNP input buffers enabling input voltages down to 150 mV below ground and rail-to-rail output swing. Its gain stage uses an external resistor across −RG/+RG pins to set precise gain via G = 5 + (80 kΩ/R_G), while the third-stage differential amplifier provides fixed ×5 gain and common-mode rejection.

Internal node voltage limits require verification using combined CM + differential signal constraints per Figure 18–21; the REF pin serves as output reference with ≤5 Ω source impedance recommended for optimal CMRR, and ESD-protected inputs tolerate ±0.3 V beyond supply rails without damage.

Key Specifications

Pinout & Package

AD8223ARZ-R7 is packaged in an 8-lead SOIC (R) with standard industry pinout and 1.27 mm lead pitch. Thermal resistance θ_JA = 155°C/W in typical PCB layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8223ARZ-R7, AD8420ARMZ delivers superior noise and CMRR at higher quiescent current and reduced supply flexibility, while INA333AIDRGT offers exceptional dc precision within narrow voltage rails but sacrifices input common-mode range and low-voltage operation headroom.

Availability

AD8223ARZ-R7 is available at Aetrix Electronics and suitable for low-power medical instrumentation, industrial thermocouple interfaces, and battery-powered data acquisition systems requiring stable component supply and long-term lifecycle support.

Supply support for AD8223ARZ-R7 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Wilmington, MA.

The AD8223 belongs to Analog Devices' precision instrumentation amplifier product line, engineered for low-power, single-supply operation in medical, industrial, and sensor interface applications where rail-to-rail output and sub-ground input capability are critical.

FAQ

What is the minimum single-supply voltage required for stable operation of the AD8223ARZ-R7?

The AD8223ARZ-R7 operates stably from +3 V to +24 V on single supply. At +3 V, it maintains rail-to-rail output swing (0.01 V to +2.5 V into 10 kΩ), 125 kHz bandwidth at G = 5, and 500 μA max quiescent current. Operation below +3 V is not characterized and may result in degraded CMRR, bandwidth, or output swing - always verify performance under actual load and temperature conditions for AD8223ARZ-R7.

Can the AD8223ARZ-R7 be used with a grounded thermocouple without external biasing?

Yes. The AD8223ARZ-R7 supports input common-mode voltages down to (−V_S) − 0.15 V, enabling direct connection of grounded thermocouples when −V_S = 0 V (single supply). This eliminates the need for input biasing resistors or level-shifting op amps. For optimal performance, keep REF pin source impedance below 5 Ω and use matched input filtering to preserve CMRR in AD8223ARZ-R7 thermocouple circuits.

What is the maximum gain error specification for the AD8223ARZ-R7 at G = 100?

At G = 100, the AD8223ARZ-R7 exhibits a maximum gain error of 0.3% (typical 0.10%) over temperature (−40°C to +85°C) with no external resistor tolerance contribution. This value excludes errors introduced by the external gain resistor R_G; total system gain error must include R_G tolerance and temperature coefficient. The AD8223ARZ-R7's internal resistor matching ensures minimal drift - 50 ppm/°C for G > 5 - making it suitable for stable gain calibration in AD8223ARZ-R7-based systems.

Does the AD8223ARZ-R7 require external capacitors on its supply pins?

Yes. The AD8223ARZ-R7 requires local decoupling: 0.1 μF ceramic and 10 μF tantalum capacitors placed close to Pins 4 (−VS) and 7 (+VS). These minimize supply-induced noise and prevent oscillation under varying load conditions. Without proper decoupling, PSRR degrades above 10 kHz and large-signal settling time increases significantly. Always route decoupling caps directly to the AD8223ARZ-R7 supply pins with short, low-inductance traces.

How does the REF pin affect output common-mode voltage in the AD8223ARZ-R7?

The AD8223ARZ-R7 output voltage is defined as V_OUT = G(V_IN+ − V_IN−) + V_REF, so the REF pin directly sets the output common-mode level. Driving REF with a precision voltage (e.g., V_S/2) centers the output for single-supply ADC interfacing. Source impedance to REF must be ≤5 Ω; higher impedances degrade CMRR due to interaction with the internal 50 kΩ resistor network. Never exceed −V_S − 0.3 V or +V_S + 0.3 V on the REF pin to avoid ESD diode conduction in AD8223ARZ-R7.