Analog Devices Inc. LT1028CS8#PBF

Overview

LT1028CS8#PBF from Analog Devices (formerly Linear Technology) is an ultralow-noise, high-speed precision operational amplifier optimized for low-source-impedance signal conditioning. It delivers 0.85nV/√Hz voltage noise at 1kHz, 50MHz gain-bandwidth product, 11V/µs slew rate, ±11.5V output swing into 2kΩ, and 0.1µV/°C typical offset drift - enabling use in photodiode transimpedance amplifiers, audio preamps, and sensor front-ends where thermal and voltage noise dominate system SNR.

For engineers reviewing the LT1028CS8#PBF datasheet, LT1028CS8#PBF pinout, LT1028CS8#PBF application, or LT1028CS8#PBF equivalent, key selection criteria include verified 10Hz–1kHz voltage noise density, guaranteed gain-bandwidth and slew rate over 0°C to 70°C, SO-8 package thermal resistance (θ_JA = 140°C/W), and compatibility with ±15V supplies in precision analog signal chains.

Technical Context

The LT1028CS8#PBF employs a high-bias-current bipolar input stage (≈1mA collector current per side) to achieve sub-1nV/√Hz voltage noise - lower than the thermal noise of a 50Ω resistor. Its architecture avoids JFET inputs to preserve voltage noise performance while maintaining 25nA max input bias current via precision cancellation circuitry.

This design enables stable operation at unity-gain (–1) without external compensation, supports rail-to-rail output swing within ±1.5V of rails under load, and integrates on-chip V_OS trim terminals for post-mount calibration - distinguishing it from the +1-stable LT1128 variant and older OP-27/OP-37 families.

Key Specifications

Pinout & Package

LT1028CS8#PBF is housed in an 8-lead plastic SOIC (S8) package with JEDEC MS-012AC footprint, 1.27mm lead pitch, and θ_JA = 140°C/W. The exposed pad is not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA1612AIDR and LT1037CN8#PBF, LT1028CS8#PBF uniquely balances sub-1nV/√Hz 1kHz noise, 50MHz GBW, and on-chip offset trim - making it optimal for high-speed, low-noise DC-coupled applications where both wideband and low-frequency fidelity are required.

Availability

LT1028CS8#PBF is available at Aetrix Electronics and suitable for photodiode transimpedance amplifiers, high-fidelity audio preamplifiers, and infrared detector signal chains requiring stable component supply across extended production cycles.

Supply support for LT1028CS8#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 full production and technical support for legacy Linear op amps including the LT1028 series.

The LT1028 product line was engineered specifically for ultralow-noise, high-speed precision analog signal conditioning - targeting applications where voltage noise, gain-bandwidth, and DC accuracy jointly determine system resolution.

FAQ

What is the maximum operating temperature range for LT1028CS8#PBF?

The LT1028CS8#PBF is specified for 0°C to 70°C ambient operation (Commercial grade). Its absolute maximum junction temperature is 150°C, and thermal resistance θ_JA is 140°C/W in the SO-8 package - requiring careful attention to PCB copper area and airflow in high-power-density layouts. Derating curves in the datasheet confirm stable operation up to 70°C ambient with ±15V supplies.

Does LT1028CS8#PBF require external compensation for unity-gain stability?

No, LT1028CS8#PBF is internally compensated for stable operation at inverting gain of –1 without external components. However, for non-inverting configurations or capacitive loads exceeding 100pF, a 15–30pF capacitor between pins 5 and 6 (OVER-COMP to V+) is recommended to maintain phase margin above 45° and prevent peaking in transient response.

Can LT1028CS8#PBF be used with single-supply operation?

LT1028CS8#PBF is designed for dual-supply operation (±4.5V to ±22V) and does not support true single-supply operation. Its input common-mode range extends to ±11V with ±15V supplies, but the output cannot swing to either rail - limiting usefulness in 0–5V or 0–3.3V systems. For single-supply applications, consider rail-to-rail alternatives like ADA4898-1.

How is input offset voltage trimmed in LT1028CS8#PBF?

LT1028CS8#PBF features two dedicated V_OS TRIM pins (pins 4 and 8) that accept a 1kΩ potentiometer wired between V+ and V–. Adjusting the wiper changes differential input bias to null offset voltage without degrading drift performance - unlike resistor-based trimming methods. The datasheet confirms this method introduces only (V_OS/300) µV/°C additional drift, preserving precision over temperature.

Is LT1028CS8#PBF pin-compatible with OP-27 or OP-37 op amps?

Yes, LT1028CS8#PBF uses the standard 8-pin SOIC footprint and pinout of OP-27/OP-37/OP-07, allowing direct socket replacement in existing designs. However, its higher supply current (8mA vs 4mA) and different noise profile require verification of thermal and power supply margins. No PCB changes are needed, but layout review is advised for high-frequency stability.