Analog Devices Inc. OP297FSZ-REEL

Overview

OP297FSZ-REEL from Analog Devices is a dual precision operational amplifier optimized for low-bias-current, high-accuracy signal conditioning in battery-powered and high-impedance sensor interfaces. It delivers 50 μV max input offset voltage, 0.6 μV/°C max drift, 100 pA max input bias current at 25°C, 2000 V/mV min open-loop gain, and operates from ±2 V to ±20 V supplies - enabling stable performance in strain gage amplifiers and long-term integrators.

For engineers reviewing the OP297FSZ-REEL datasheet, OP297FSZ-REEL pinout, OP297FSZ-REEL application, or OP297FSZ-REEL equivalent, key selection criteria include verified picoamp-level bias current stability over temperature, guaranteed CMRR ≥120 dB, rail-to-rail input common-mode range (±13 V), and SOIC_N package compatibility with automated SMT assembly for instrumentation-grade analog front-ends.

Technical Context

The OP297FSZ-REEL employs a super-beta bipolar input stage with bias current cancellation, maintaining ≤450 pA input bias current across −40°C to +85°C - unlike FET-input op amps whose bias current doubles per 10°C rise. Its open-loop gain exceeds 2000 V/mV with <0.1 μV p-p 0.1–10 Hz noise, ensuring linearity in high-gain configurations such as photodiode transimpedance stages.

Common-mode rejection remains ≥114 dB up to 100 kHz, and power supply rejection holds ≥114 dB across ±2.5 V to ±20 V operation. The device achieves ±13 V output swing into 10 kΩ at ±15 V supplies while consuming only 625 μA per amplifier - balancing precision, low power, and wide supply flexibility.

Key Specifications

Pinout & Package

OP297FSZ-REEL is housed in an 8-lead SOIC_N (R-8) package per JEDEC MS-012-AA, with 1.27 mm lead pitch, 5.00 mm × 4.00 mm body, and RoHS-compliant matte tin lead finish. Thermal resistance θ_JA = 150°C/W reflects standard PCB mounting with 2 oz copper and minimal thermal relief.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OP2177ARZ-REEL and LTC1052CS8#TRPBF, OP297FSZ-REEL uniquely balances picoamp input bias, 500 kHz bandwidth, and 625 μA supply current in a standard SOIC package - making it the only choice for battery-powered, high-impedance, moderate-bandwidth precision amplification.

Availability

OP297FSZ-REEL is available at Aetrix Electronics and suitable for strain gage amplifiers, thermocouple signal conditioning, and photocurrent monitoring requiring stable component supply across industrial, medical, and test equipment production cycles.

Supply support for OP297FSZ-REEL 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 OP297 product line was designed specifically for precision, low-power, high-input-impedance analog signal conditioning - targeting applications where bias current stability, offset drift, and supply flexibility outweigh raw speed requirements.

FAQ

What is the maximum input bias current specification for OP297FSZ-REEL over temperature?

The OP297FSZ-REEL guarantees ≤450 pA input bias current across its full operating range of −40°C to +85°C, as specified in Table 2 of the Rev. G datasheet. This is achieved via super-beta input transistors with active bias cancellation - distinguishing it from FET-input op amps whose bias current rises exponentially with temperature. At 25°C, the limit is tighter: ≤100 pA. This pA-level stability is essential for long-hold sample-and-hold circuits and high-resistance sensor interfaces where leakage would otherwise dominate error budgets.

Does OP297FSZ-REEL support single-supply operation?

OP297FSZ-REEL does not support true single-supply operation in the conventional sense, as it requires dual ±2 V to ±20 V rails. However, it can be used in single-supply systems via split-rail generation - for example, using a charge pump or dual LDO to derive ±2.5 V from a 5 V rail. Its input common-mode range extends to within 1 V of either rail, and output swings to within 1 V of the rails with 10 kΩ loads, enabling effective utilization of limited headroom. The datasheet explicitly specifies performance only under dual-supply conditions.

What is the recommended PCB layout practice to preserve OP297FSZ-REEL's low-bias-current performance?

To preserve the picoamp-level input bias current of OP297FSZ-REEL, Analog Devices mandates guard ring implementation around both input pins (Pins 2, 3, 6, 7). The guard trace must be driven at the same potential as the input node - grounded for inverting configurations, or tied to the inverting input's common-mode voltage for non-inverting setups. Board surfaces require conformal coating to suppress humidity-induced leakage, and cleaning must remove all ionic residues. Even clean FR-4 exhibits ~100 pA inter-trace leakage, making guarding non-optional for sub-nA accuracy.

How does OP297FSZ-REEL's open-loop gain linearity impact high-gain closed-loop designs?

OP297FSZ-REEL's minimum open-loop gain of 2000 V/mV (2000000 V/V) combined with constant gain linearity - verified over −55°C to +125°C in Figure 30 - ensures predictable closed-loop behavior at gains up to 1000. Unlike op amps with gain compression near rail limits, the OP297FSZ-REEL maintains linear transfer characteristics across its full output swing, reducing harmonic distortion and gain error in precision absolute-value amplifiers and logarithmic converters. This linearity directly enables <0.05% gain error without trimming in 100× instrumentation amplifier topologies.

Is OP297FSZ-REEL pin-compatible with other dual op amps in SOIC-8 packages?

OP297FSZ-REEL uses the industry-standard 8-lead SOIC_N (R-8) footprint per JEDEC MS-012-AA, matching physical dimensions and lead pitch (1.27 mm) of common dual op amps like the OP2177ARZ-REEL and AD8628ARZ-REEL. However, pin function differs: OP297FSZ-REEL places V− on Pin 4 and V+ on Pin 8, whereas many dual op amps (e.g., LM358) place V+ on Pin 8 and V− on Pin 4 - requiring schematic and layout verification. No functional or electrical pin compatibility is claimed; substitution demands full circuit validation.