Analog Devices Inc. LT1815IS8#PBF

Overview

LT1815IS8#PBF from Analog Devices (formerly Linear Technology) is a single-channel, high-speed, programmable-current operational amplifier in an 8-lead SO package. It delivers 220MHz gain-bandwidth, 1500V/µs slew rate, and 6.5mA supply current per amplifier at ±5V supplies, with ±3.5V input common-mode range and ±3.5V output swing into 100Ω under ±5V operation - used in precision video buffers and RF signal conditioning stages.

For engineers reviewing the LT1815IS8#PBF datasheet, LT1815IS8#PBF pinout, LT1815IS8#PBF application, or LT1815IS8#PBF equivalent, key selection criteria include guaranteed –40°C to 85°C operation, programmable current mode via ISET pin, unity-gain stability, low 6nV/√Hz input noise, and SO-8 package compatibility with industrial analog signal chains.

Technical Context

The LT1815IS8#PBF employs a voltage-feedback topology with current-feedback slewing characteristics, enabling fast transient response without sacrificing DC accuracy. Its input stage uses complementary NPN/PNP emitter followers for bias current cancellation, supporting ±3.5V common-mode input range at ±5V supplies and rail-to-rail output swing capability on single 5V operation (1V to 4V into 100Ω).

It features an ISET pin for programmable supply current: full-speed mode (6.5mA typ.) with ≤75Ω to V–, and low-power mode (1.5mA typ.) with 40kΩ to V–, reducing bandwidth to 50MHz and slew rate to 750V/µs - enabling dynamic trade-offs between speed, power, and thermal load in space-constrained designs.

Key Specifications

Pinout & Package

LT1815IS8#PBF is housed in an 8-lead plastic SO (Small Outline) package with standard SO-8 footprint (5.0mm × 6.2mm), JEDEC MS-012AC compliant, and rated for θ_JA = 150°C/W with minimal PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed operational amplifier applications.

Compared with ADA4897-1ARZ-R7 and LMH6629MA/NOPB, the LT1815IS8#PBF uniquely combines programmable current, SO-8 packaging, and guaranteed –40°C to 85°C operation - making it optimal for industrial video, test equipment, and embedded DAQ where thermal management and supply flexibility are critical.

Availability

LT1815IS8#PBF is available at Aetrix Electronics and suitable for video line driving, RF signal conditioning, and precision active filtering requiring stable component supply across extended temperature ranges.

Supply support for LT1815IS8#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 acquired Linear Technology in 2017 and maintains its high-performance analog portfolio, emphasizing precision, speed, and reliability in signal conditioning ICs.

The LT1815IS8#PBF belongs to Linear's LT1815/LT1816/LT1817 family of programmable-current op-amps designed for applications demanding both high bandwidth and low power - especially where thermal constraints limit continuous full-speed operation.

FAQ

What is the maximum operating junction temperature for LT1815IS8#PBF?

The LT1815IS8#PBF has a maximum junction temperature (T_JMAX) of 150°C. This rating applies to the SO-8 package under specified thermal conditions (θ_JA = 150°C/W). Derating is required above ambient temperatures where power dissipation exceeds safe limits - for example, at 85°C ambient with ±5V supplies and 100Ω load, calculated T_J reaches 138°C, leaving 12°C margin. Always verify thermal design using the formula T_J = T_A + (n • P_D • θ_JA).

Does LT1815IS8#PBF support single-supply operation?

Yes, the LT1815IS8#PBF operates from a single 5V supply with rail-to-rail output swing from 1V to 4V into a 100Ω load referenced to 2.5V. Input common-mode range extends from 0.9V to 4.1V under these conditions, enabling direct interfacing with 3.3V logic and mid-supply referenced ADCs. The device remains unity-gain stable and retains 200MHz GBW and 750V/µs slew rate in low-power mode, making it suitable for portable instrumentation and battery-powered signal chains.

How does the ISET pin function on LT1815IS8#PBF?

The ISET pin on LT1815IS8#PBF controls supply current and bandwidth: connecting it to V– through ≤75Ω enables full-speed mode (6.5mA, 220MHz GBW, 1500V/µs), while a 40kΩ resistor sets low-power mode (1.5mA, 50MHz GBW, 750V/µs). This pin is functional only on LT1815S6 and LT1816A variants - the LT1815IS8#PBF is a standard-speed part without ISET functionality. Confusion arises from shared family documentation; the IS8 package variant does not implement programmable current.

What is the input bias current specification for LT1815IS8#PBF?

The LT1815IS8#PBF specifies ±8μA maximum input bias current over the full –40°C to 85°C temperature range. This value reflects worst-case bipolar input stage behavior, where NPN/PNP base currents partially cancel but polarity depends on process variation. For DC-critical applications, balanced source impedances (e.g., 100Ω on both +IN and –IN) limit offset contribution from bias current to <80μV, versus up to 0.8mV with unbalanced sources - a key layout consideration confirmed in the datasheet's Applications Information section.

Is LT1815IS8#PBF unity-gain stable?

Yes, the LT1815IS8#PBF is explicitly unity-gain stable per its datasheet, with no external compensation required for AV = 1 configurations. This stability is verified across temperature and supply variations, including ±5V and single 5V operation. The device achieves this via internal dominant-pole compensation optimized for 220MHz GBW and 1500V/µs slew rate - enabling robust voltage follower, active filter, and cable driver implementations without risk of oscillation or peaking.