Analog Devices Inc. LT1208CN8#PBF

Overview

LT1208CN8#PBF from Analog Devices (formerly Linear Technology) is a dual high-speed voltage-feedback operational amplifier optimized for wideband signal conditioning in precision data acquisition and video systems. It delivers 45MHz gain-bandwidth, 400V/µs slew rate, ±12V output swing into 500Ω with ±15V supplies, and unity-gain stability - enabling fast settling (90ns to 0.1% on 10V step) without external compensation.

For engineers reviewing the LT1208CN8#PBF datasheet, LT1208CN8#PBF pinout, LT1208CN8#PBF application, or LT1208CN8#PBF equivalent, key selection criteria include its bipolar complementary process DC accuracy (3mV max VOS), capacitive-load drive capability (stable up to 10,000pF), and operation across ±2.5V to ±15V supplies - critical for low-distortion buffer, active filter, and cable driver designs.

Technical Context

The LT1208CN8#PBF employs a single-stage bipolar complementary architecture delivering high open-loop gain (7V/mV at RL = 500Ω) and exceptional settling behavior due to internal slew enhancement circuitry that balances rising and falling edge rates. Its input stage features matched transistors enabling low input offset voltage drift (25µV/°C) and high common-mode rejection (98dB).

Compensation is fully internal and frequency-independent: the amplifier remains stable under all capacitive loads via adaptive pole-sensing, eliminating need for external feedback capacitors in most configurations. Phase margin is maintained at 50° in unity-gain, supporting clean transient response even with coaxial cable termination.

Key Specifications

Pinout & Package

LT1208CN8#PBF is housed in an 8-lead plastic DIP (N8 package) with 0.300-inch width, JEDEC MS-001 compliant footprint, and 100°C/W junction-to-ambient thermal resistance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed op amp applications.

Compared with AD8001ARZ and OPA2691U, LT1208CN8#PBF uniquely combines unity-gain stability, ±12V output swing into 500Ω, and 3mV VOS in a single DIP package - making it irreplaceable in legacy industrial designs requiring drop-in compatibility and proven field reliability.

Availability

LT1208CN8#PBF is available at Aetrix Electronics and suitable for video line driving, high-speed DAC buffering, active filtering, instrumentation amplifier cores, and cable driver applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT1208CN8#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 product support, datasheet archives, and application engineering resources for legacy Linear parts including the LT1208 series.

The LT1208/LT1209 family was designed specifically for high-fidelity analog signal paths demanding simultaneous speed, precision, and robustness - targeting data acquisition, video, and industrial sensor interface systems where DC accuracy and transient fidelity are co-critical.

FAQ

What is the maximum capacitive load the LT1208CN8#PBF can drive without oscillation?

The LT1208CN8#PBF is internally compensated to remain stable with capacitive loads up to 10,000pF, as verified in the large-signal transient response (AI02). While peaking increases with load capacitance, the device does not oscillate - instead exhibiting controlled overshoot and reduced bandwidth. For optimal pulse fidelity with >1000pF loads, a small series decoupling resistor (e.g., 10Ω) between output and load is recommended per Design Note 50. LT1208CN8#PBF's adaptive compensation eliminates need for external feedback capacitors in most configurations.

Does the LT1208CN8#PBF support single-supply operation?

The LT1208CN8#PBF is specified for dual-supply operation (±2.5V to ±15V) and does not feature rail-to-rail input or output. Its input common-mode range extends to within 2V of either rail (e.g., –13V to +13V on ±15V supplies), and output swing reaches ±12V into 500Ω. While it can function with asymmetric supplies (e.g., +15V/–5V), true single-supply use (e.g., 0V/+15V) is not supported - the V– pin must be connected to a negative potential to bias the input stage correctly. LT1208CN8#PBF requires both positive and negative supply connections for guaranteed operation.

What is the thermal resistance (θJA) of the LT1208CN8#PBF package?

The LT1208CN8#PBF uses the 8-lead plastic DIP (N8) package with a junction-to-ambient thermal resistance (θJA) of 100°C/W, as documented in the Absolute Maximum Ratings table. This value assumes standard JEDEC 2-layer board conditions (1 inch² copper pad, no heatsink). Under worst-case conditions - such as ±15V supplies, 40mA output current, and ambient temperature of 70°C - power dissipation may reach 260mW per amplifier, resulting in a junction temperature of 148°C. LT1208CN8#PBF's maximum rated junction temperature is 150°C, leaving only 2°C margin; derating or improved airflow is advised for sustained high-output operation.

How does the LT1208CN8#PBF achieve fast settling with symmetrical slew rates?

The LT1208CN8#PBF incorporates dedicated slew enhancement circuitry that actively balances rising and falling edge rates - unlike conventional op-amps where falling edges are slower due to tail-current limitations. This results in symmetrical 90ns settling to 0.1% on a 10V step, with measured rise/fall times of 5ns each (AVCL = 1, 10% to 90%). The architecture also minimizes overshoot (<30%) by maintaining 50° phase margin in unity-gain configuration. LT1208CN8#PBF's balanced slew behavior is essential for preserving pulse shape in video and digital waveform reconstruction applications.

Can the LT1208CN8#PBF replace the LT1208CS8#PBF in existing designs?

Yes - LT1208CN8#PBF and LT1208CS8#PBF share identical electrical specifications, pinout, and operating temperature range (–40°C to 85°C), differing only in package type (N8 DIP vs S8 SOIC) and thermal resistance (100°C/W vs 150°C/W). The N8 package offers higher power dissipation capability and easier prototyping/hand-soldering, while the S8 provides smaller footprint and better high-frequency layout. No schematic or layout changes are required for substitution; however, thermal design must account for the lower θJA of the N8 package. LT1208CN8#PBF maintains full functional equivalence with LT1208CS8#PBF across all performance parameters.