Analog Devices Inc. AD623BR

Overview

AD623BR from Analog Devices is a rail-to-rail output, single- or dual-supply instrumentation amplifier with gain programmable from 1 to 1000 via one external resistor. It delivers 800 kHz bandwidth at G = 1, 35 nV/√Hz input-referred voltage noise, and 0.05% max gain error (G = 1) in medical transducer signal conditioning circuits.

For engineers reviewing the AD623BR datasheet, AD623BR pinout, AD623BR application, or AD623BR equivalent, this page provides verified specifications, package mapping, functional pin roles, real-world use cases, and validated alternative options for low-power precision amplification in constrained supply environments.

Technical Context

The AD623BR implements a three-op-amp instrumentation architecture with internal laser-trimmed thin-film resistors enabling high CMRR (up to 110 dB at G = 100) and stable gain accuracy across temperature. Its input stage supports common-mode voltages down to 150 mV below ground on single supply, and its output buffer delivers rail-to-rail swing with <0.5 V headroom at ±5 V supplies.

Gain is set by a single external resistor (RG) connected between pins 1 (−RG) and 8 (+RG), where G = 1 + (100 kΩ/RG). The REF pin (pin 5) allows precise output common-mode level control independent of gain setting, supporting level-shifting in mixed-signal systems.

Key Specifications

Pinout & Package

AD623BR is supplied in an 8-lead SOIC package (R-8), conforming to industry-standard pinout for drop-in compatibility with legacy instrumentation amplifier designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8422ARMZ and INA333AIDR, the AD623BR uniquely balances programmable gain (1–1000), rail-to-rail output, and sub-600 µA quiescent current-making it optimal for portable, multi-sensor systems requiring design flexibility and low power.

Availability

AD623BR is available at Aetrix Electronics and suitable for low-power medical instrumentation, transducer interfaces, thermocouple amplifiers, and industrial process controls requiring stable component supply across extended temperature ranges.

Supply support for AD623BR 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 AD623 product line was engineered for precision signal conditioning in resource-constrained environments-delivering rail-to-rail output, single-supply operation, and programmable gain without sacrificing accuracy or noise performance.

FAQ

What is the maximum gain achievable with AD623BR, and how is it set?

The AD623BR supports a gain range of 1 to 1000, set by a single external resistor (RG) connected between pins 1 (−RG) and 8 (+RG), using the formula G = 1 + (100 kΩ/RG). At G = 1000, RG = 100 Ω; the AD623BR datasheet specifies 0.35% max gain error at this setting. No internal trimming is required-the AD623BR achieves this range inherently through its laser-trimmed resistor network and three-op-amp topology.

Does AD623BR support true single-supply operation with input signals below ground?

Yes, the AD623BR accepts input common-mode voltages as low as 150 mV below the negative supply rail (−VS − 0.15 V), enabling operation with inputs referenced to ground on a single +5 V supply. This eliminates the need for a negative bias supply when amplifying AC-coupled or bipolar sensor outputs such as piezoelectric accelerometers or certain thermopile configurations. The AD623BR maintains specified CMRR and gain accuracy across this extended range.

What is the typical quiescent current of AD623BR, and how does it vary with supply voltage?

The AD623BR draws 305–480 µA in single-supply mode and 375–550 µA in dual-supply mode, with a maximum of 550 µA across temperature. Quiescent current remains stable across its full supply range (2.7–12 V single or ±2.5 V to ±6 V dual); it does not scale with supply voltage. This consistent low power draw makes the AD623BR especially suitable for always-on battery-powered instrumentation where predictable current consumption is critical for runtime estimation.

Can AD623BR drive standard 10 kΩ ADC inputs while maintaining 0.01% settling accuracy?

Yes, the AD623BR settles to 0.01% in 20 µs at G = 10 into a 10 kΩ load with a 4 V step, per the Rev. G datasheet. Its rail-to-rail output stage delivers full swing with minimal overshoot, and its 0.3 V/µs slew rate ensures monotonic settling. When paired with SAR ADCs such as the AD7980 or ADS8860, the AD623BR meets timing requirements without external buffering-reducing component count and board space in compact data acquisition modules.

How does the REF pin (pin 5) function in AD623BR, and what voltage range can it accept?

The REF pin on the AD623BR sets the output common-mode voltage with unity gain and ±0.02% accuracy. It accepts any voltage between −VS and +VS, allowing precise level-shifting-for example, biasing the output to 1.65 V for a 3.3 V ADC. The AD623BR's REF input has 100 kΩ impedance and draws ≤60 µA, enabling direct drive from precision voltage references (e.g., ADR3425) or buffered DAC outputs without loading error. This feature decouples gain setting from output centering.