Analog Devices Inc. LT1881ACN8#PBF

Overview

LT1881ACN8#PBF from Analog Devices (acquired Linear Technology) is a dual rail-to-rail output, picoamp-input precision operational amplifier in an 8-lead PDIP package. It delivers 50 μV max input offset voltage, 200 pA max input bias current, and rail-to-rail output swing within 40 mV of V– and 220 mV of V+, operating from 2.7 V to 36 V total supply. It is used in thermocouple amplifiers and photo-current sensing where ultra-low input error and high impedance interface are critical.

For engineers reviewing the LT1881ACN8#PBF datasheet, LT1881ACN8#PBF pinout, LT1881ACN8#PBF application, or LT1881ACN8#PBF equivalent, key selection factors include guaranteed 0°C to 70°C operation, A-grade precision matching (ΔVOS ≤ 125 μV), stability with 1000 pF capacitive loads at unity gain, and compatibility with single-supply battery-powered systems requiring sub-100 μV DC accuracy.

Technical Context

The LT1881ACN8#PBF implements a precision bipolar input stage with on-chip input bias current cancellation, enabling ultralow 200 pA max IB while maintaining low noise (14 nV/√Hz) and high open-loop gain (>500 V/mV into 10 kΩ). Its rail-to-rail output stage uses complementary common-emitter followers for low saturation voltage across temperature.

It supports both single-supply (e.g., 5 V, 0 V) and split-supply (±15 V) operation, with input common-mode range limited to V– +1.0 V to V+ –1.0 V. Channel separation exceeds 120 dB at 1 kHz, ensuring minimal crosstalk in dual-channel instrumentation signal conditioning.

Key Specifications

Pinout & Package

LT1881ACN8#PBF is housed in an 8-lead plastic dual in-line package (PDIP), narrow body (0.300"), with JEDEC MS-001 compliant footprint. Thermal resistance θ_JA = 130°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision op amp applications.

Compared with LT1881CS8#PBF, the LT1881ACN8#PBF offers lower thermal resistance and through-hole mounting for lab validation, while OPA2188AIDR trades higher power and no PDIP for orders-of-magnitude lower drift - making LT1881ACN8#PBF optimal for cost-sensitive, medium-precision, through-hole instrumentation.

Availability

LT1881ACN8#PBF is available at Aetrix Electronics and suitable for thermocouple amplifiers, bridge transducer conditioners, and battery-powered precision measurement systems requiring stable component supply across production lifecycles.

Supply support for LT1881ACN8#PBF 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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through the acquisition of Linear Technology in 2017.

The LT1881 family belongs to ADI's precision op amp product line, designed specifically for high-accuracy DC-coupled signal conditioning in instrumentation, industrial sensing, and medical diagnostics where picoamp input bias and microvolt offset are essential.

FAQ

What is the maximum input bias current specification for LT1881ACN8#PBF over its operating temperature range?

The LT1881ACN8#PBF has a maximum input bias current of 200 pA at 0°C to 70°C ambient temperature, with typical value of 100 pA. This specification is guaranteed for the "A" grade version and applies across the full specified temperature range - critical for preserving accuracy in high-impedance sensor interfaces where even 100 pA can induce significant error.

Does LT1881ACN8#PBF support single-supply operation, and what is its minimum supply voltage?

Yes, LT1881ACN8#PBF supports true single-supply operation down to 2.7 V total supply (e.g., 2.7 V to GND). Its rail-to-rail output stage swings to within 40 mV of GND and 220 mV of V+, enabling full-scale signal utilization in 3.3 V and 5 V systems - a key advantage over older precision op amps requiring dual supplies for comparable DC accuracy.

What is the guaranteed input offset voltage for LT1881ACN8#PBF, and how does it compare to the standard LT1881CN8#PBF?

The LT1881ACN8#PBF guarantees a maximum input offset voltage of 50 μV at 0°C to 70°C, whereas the standard LT1881CN8#PBF is rated at 80 μV max. This tighter 50 μV spec reflects factory trimming and makes LT1881ACN8#PBF suitable for applications demanding higher initial DC accuracy - such as 16-bit data acquisition without software calibration.

Can LT1881ACN8#PBF drive a 1000 pF capacitive load in unity-gain configuration without oscillation?

Yes, LT1881ACN8#PBF is explicitly characterized and guaranteed stable with up to 1000 pF capacitive load in unity-gain follower configuration - a key differentiator from earlier precision op amps like LT1884. This allows direct connection to long cables, piezoelectric sensors, or ADC input capacitors without external isolation resistors or compensation networks.

What is the pin-compatible alternative to LT1881ACN8#PBF in surface-mount packaging?

The LT1881ACS8#PBF is the direct surface-mount equivalent of LT1881ACN8#PBF - sharing identical A-grade electrical specifications (50 μV VOS max, 200 pA IB max), same pinout, and functional compatibility, but housed in an 8-lead SOIC (S8) package instead of PDIP. No circuit redesign is needed beyond footprint adaptation.