Analog Devices Inc. OP297GPZ

Overview

OP297GPZ from Analog Devices is a dual low-bias-current precision operational amplifier in an 8-lead PDIP package, delivering 50 μV max input offset voltage, 0.6 μV/°C max drift, and 100 pA max input bias current at 25°C. It operates from ±2 V to ±20 V supplies and supports high-accuracy signal conditioning in strain gage amplifiers and thermocouple interfaces.

For engineers reviewing the OP297GPZ datasheet, OP297GPZ pinout, OP297GPZ application, or OP297GPZ equivalent, key selection criteria include guaranteed picoamp-level bias current over temperature, 120 dB minimum CMRR, 2000 V/mV minimum open-loop gain, and compatibility with low-voltage battery-powered systems requiring long-term DC stability.

Technical Context

The OP297GPZ employs a super-beta input stage with bias current cancellation to maintain sub-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, ensuring high linearity in closed-loop gains up to 1000×.

Common-mode rejection remains ≥114 dB over frequency (1 Hz–1 MHz) and supply voltage (±2.5 V–±20 V), while power supply rejection stays ≥108 dB across the same range. Input resistance is 500 GΩ common-mode and 30 MΩ differential, enabling ultra-high-impedance sensor interfacing without guard-ring dependency in many layouts.

Key Specifications

Pinout & Package

OP297GPZ is housed in an 8-lead plastic dual in-line package (PDIP, N-8, P-Suffix), with 0.300-inch body width, 0.100-inch lead pitch, and through-hole mounting compatible with standard PCB footprints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OP2177ARZ and AD8628ARZ, OP297GPZ uniquely balances PDIP availability, ±2 V supply capability, and guaranteed sub-450 pA bias current across −40°C to +85°C - making it the only choice for ruggedized, through-hole, wide-temperature precision analog front-ends.

Availability

OP297GPZ is available at Aetrix Electronics and suitable for strain gage amplifiers, thermocouple signal conditioners, and battery-powered precision data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for OP297GPZ 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 Norwood, MA, with design centers worldwide and ISO 9001-certified manufacturing.

The OP297 product line was engineered for high-precision, low-power, wide-temperature analog signal conditioning - specifically targeting instrumentation, sensor interfaces, and portable test equipment where bias current stability and DC accuracy outweigh raw speed.

FAQ

What is the maximum input bias current specification for OP297GPZ over its full operating temperature range?

The OP297GPZ guarantees ≤450 pA input bias current per amplifier across −40°C to +85°C, as specified in Table 2 of the Rev. G datasheet. This value is measured at V_CM = 0 V and represents the worst-case bound for both inputs. Unlike FET-input op amps, this picoamp-level performance is maintained across temperature due to its super-beta input stage with active bias cancellation - critical for long-term integrators and high-impedance sensor nodes.

Does OP297GPZ support operation from ±2 V supplies, and what are the implications for output swing?

Yes, OP297GPZ is fully specified for operation from ±2 V supplies (i.e., total 4 V). Under these conditions, the output swing is guaranteed to be ≥±13 V into 10 kΩ load when powered from ±15 V, but at ±2 V, typical swing is ≥±1.0 V - sufficient for low-voltage rail-to-rail sensing in portable medical or IoT devices. The input common-mode range extends to within 1 V of either rail, enabling direct interface with 0–3.3 V ADC references without level shifting.

How does the OP297GPZ compare to FET-input op amps in terms of input bias current versus temperature?

OP297GPZ maintains ≤450 pA input bias current over −40°C to +85°C, whereas typical FET-input op amps start near 100 pA at 25°C but double every 10°C - reaching >1 nA above 85°C. This exponential degradation makes FET devices unsuitable for high-temperature integrators or log amplifiers. OP297GPZ's super-beta bipolar input with cancellation delivers stable picoamp behavior, verified in Figure 8 of the datasheet, making it the preferred solution for military and automotive under-hood applications.

Can OP297GPZ drive capacitive loads, and what is the maximum stable capacitance?

Yes, OP297GPZ exhibits excellent capacitive load tolerance: Figure 27 in the Rev. G datasheet shows stable small-signal transient response with 1000 pF load at unity gain. No external compensation is required up to this value. For loads >1000 pF, series isolation resistance (e.g., 10–100 Ω) at the output is recommended to maintain phase margin. This capability simplifies filter design in anti-aliasing and reconstruction stages without sacrificing precision.

Is OP297GPZ RoHS compliant, and what does the 'Z' suffix indicate in the ordering code?

Yes, OP297GPZ is RoHS compliant - the 'Z' suffix explicitly denotes compliance with EU Directive 2011/65/EU (RoHS 2), confirmed in the Ordering Guide on page 14 of the Rev. G datasheet. The 'P' suffix indicates plastic DIP packaging (N-8), and 'GP' denotes the commercial-grade temperature range (−40°C to +85°C) with guaranteed performance per the OP297G grade. All OP297GPZ units shipped by Aetrix Electronics carry full RoHS documentation and material declarations.