Analog Devices Inc. LT6221IS8#PBF

Overview

LT6221IS8#PBF from Analog Devices (formerly Linear Technology) is a single, rail-to-rail input and output precision operational amplifier optimized for low-power, high-speed signal conditioning in 3V–5V systems. It delivers 60MHz gain-bandwidth product, 20V/µs slew rate, <350µV input offset voltage, 1mA quiescent current per amplifier, and rail-to-rail output swing within 10mV of either supply rail - enabling high-fidelity buffering and driving of ADC inputs in portable instrumentation.

For engineers reviewing the LT6221IS8#PBF datasheet, LT6221IS8#PBF pinout, LT6221IS8#PBF application, or LT6221IS8#PBF equivalent, key selection criteria include guaranteed –40°C to +85°C operation, SO-8 standard op amp pinout compatibility, low 10nV/√Hz input voltage noise, and robust input common-mode range extending beyond both rails - critical for sensor front-ends and precision analog data acquisition.

Technical Context

The LT6221IS8#PBF employs a dual-input-stage architecture (PNP + NPN differential pairs) that automatically transitions between stages across the full input common-mode range (–40°C to +85°C), ensuring consistent bias current behavior and no phase reversal when driven beyond the rails. Its output stage uses complementary Class AB topology to sustain ±50mA peak output current while maintaining rail-to-rail swing under load.

Internally compensated for unity-gain stability, the device achieves 60MHz GBW with 102dB CMRR and 105dB PSRR at DC, supporting high-accuracy closed-loop configurations in noisy industrial environments. The SO-8 package features thermally enhanced layout with VS– connected to exposed pad (in DFN variants) - though not applicable to this SO-8 variant - and supports stable operation down to 2.2V total supply.

Key Specifications

Pinout & Package

LT6221IS8#PBF is housed in an 8-lead plastic SO (Small Outline) package with industry-standard op amp pinout and JEDEC MS-012AC footprint. Thermal resistance θ_JA = 190°C/W (on 2-layer board with minimal copper).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT6221IS8#PBF, OPA350UA trades 22MHz bandwidth for lower noise, while AD8605ARZ improves DC accuracy at the cost of slew-limited transient response - making LT6221IS8#PBF optimal for wideband, rail-to-rail, industrial-temperature signal conditioning where balanced AC/DC performance is essential.

Availability

LT6221IS8#PBF is available at Aetrix Electronics and suitable for industrial automation, portable medical devices, and test & measurement equipment requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LT6221IS8#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors.

The LT6221 belongs to Linear's precision high-speed op amp family, designed specifically for applications demanding simultaneous rail-to-rail operation, low power, wide bandwidth, and guaranteed performance across –40°C to +85°C.

FAQ

What is the maximum operating supply voltage for LT6221IS8#PBF?

The absolute maximum total supply voltage (VS+ to VS–) for LT6221IS8#PBF is 12.6V. Operation above this rating risks permanent damage. For reliable long-term use, Analog Devices specifies continuous operation up to 12.6V, with full parametric performance guaranteed from 2.2V to 12.6V. At 12.6V, quiescent current remains within 1.5mA max across –40°C to +85°C.

Does LT6221IS8#PBF support true rail-to-rail input common-mode range?

Yes, LT6221IS8#PBF supports true rail-to-rail input common-mode range: its inputs operate from VS– to VS+, including both supply rails. This is achieved via dual PNP/NPN input stages that auto-switch across the range. Input current remains below 150nA max across the full range, and no phase reversal occurs even when inputs exceed the rails by ±10mA (within Absolute Maximum Ratings).

Can LT6221IS8#PBF drive heavy capacitive loads directly?

LT6221IS8#PBF is not unity-gain stable into large capacitive loads without isolation. Datasheet testing shows >40% overshoot with 100pF load and no series resistor. For loads >50pF, a series output resistor (ROS = 10Ω–50Ω) is required to maintain stability. With ROS = 20Ω, it drives 1000pF with <5% overshoot - critical for driving ADC input capacitors or long PCB traces.

What is the guaranteed input offset voltage specification for LT6221IS8#PBF over temperature?

For LT6221IS8#PBF (I-grade, –40°C to +85°C), the input offset voltage is guaranteed ≤700µV max at VCM = 0V and ≤2000µV max at VCM = VS. Typical VOS is <350µV at 25°C. The part exhibits <7.5µV/°C drift (S5 package), and matching between channels is ≤1200µV over temperature - verified per datasheet Table 5 (–40°C to +85°C conditions).

Is LT6221IS8#PBF pin-compatible with standard SO-8 op amps like LM358 or TL072?

LT6221IS8#PBF uses the industry-standard SO-8 op amp pinout (VOUT, –IN, +IN, VS–, NC, NC, VS+, NC), making it mechanically compatible with LM358 and TL072 footprints. However, it is not functionally drop-in: LT6221IS8#PBF is single-channel (vs. dual LM358/TL072), requires no external compensation, and has different biasing - PCB layout reuse is possible, but schematic review and stability validation are mandatory before substitution.