Texas Instruments OPA355NA/3KG4

Overview

OPA355NA/3KG4 from Texas Instruments is a single-channel, high-speed CMOS operational amplifier optimized for video and wideband signal conditioning. It delivers 450 MHz unity-gain bandwidth, 200 MHz gain-bandwidth product, rail-to-rail output swing within 100 mV of rails, 5.8 nV/√Hz input voltage noise, and 3 pA input bias current - enabling precision, low-distortion amplification in 2.5 V to 5.5 V single-supply systems such as composite video buffers and photodiode transimpedance stages.

For engineers reviewing the OPA355NA/3KG4 datasheet, OPA355NA/3KG4 pinout, OPA355NA/3KG4 application, or OPA355NA/3KG4 equivalent, key selection criteria include its 100 ns enable time, 30 ns disable time, thermal shutdown protection at 160°C, differential gain/phase error of 0.02%/0.05°, and support for output multiplexing via high-impedance shutdown state.

Technical Context

The OPA355NA/3KG4 implements a voltage-feedback CMOS architecture with unity-gain stability and Class AB output stage, supporting stable operation from G = 1 to G ≥ 10. Its input common-mode range extends 100 mV below V– and up to 1.5 V below V+, enabling ground-referenced inputs in single-supply configurations.

It integrates a digital enable control pin referenced to V– (or ground in single-supply), delivering 3.4 µA shutdown current per channel and fast 100 ns enable / 30 ns disable transitions. Thermal shutdown activates at 160°C junction temperature and resets at 140°C, protecting against sustained overloads.

Key Specifications

Pinout & Package

OPA355NA/3KG4 is packaged in an 8-pin SOIC (D package) with 4.90 mm × 3.91 mm body size, rated for –40°C to +125°C operation. The package supports standard surface-mount reflow and provides adequate thermal dissipation (θJA = 125°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA355NA/3KG4, OPA356IDBVR trades shutdown capability for lower noise, while LMH6629MA/NOPB offers extreme bandwidth at significantly higher power and cost - making OPA355NA/3KG4 the optimal balance for video, TIA, and ADC buffer roles requiring fast enable/disable and thermal safety.

Availability

OPA355NA/3KG4 is available at Aetrix Electronics and suitable for video processing, photodiode transimpedance amplification, and ADC input buffering requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for OPA355NA/3KG4 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in high-performance op amps and precision signal chain solutions.

The OPA355NA/3KG4 belongs to TI's OPAx355 family of high-speed CMOS op amps, designed specifically for video, optical networking, and wideband instrumentation applications demanding low noise, rail-to-rail output, and integrated power management.

FAQ

What is the operating supply voltage range for the OPA355NA/3KG4?

The OPA355NA/3KG4 operates from 2.5 V to 5.5 V total supply voltage, with recommended conditions specifying 2.7 V to 5.5 V. It supports both single-supply (e.g., 3.3 V or 5 V) and split-supply (±1.25 V to ±2.75 V) configurations. Absolute maximum supply is 7.5 V between V+ and V–; exceeding this risks permanent damage. The OPA355NA/3KG4 maintains specified performance across the full –40°C to +125°C temperature range within this voltage window.

Does the OPA355NA/3KG4 support rail-to-rail input operation?

No, the OPA355NA/3KG4 does not support rail-to-rail input. Its input common-mode voltage range extends from V– – 0.1 V to V+ – 1.5 V, meaning it includes ground in single-supply use but cannot accept signals within 1.5 V of V+. However, the output is rail-to-rail - swinging within 100 mV of both supply rails under 150 Ω load. This asymmetry makes the OPA355NA/3KG4 ideal for ground-referenced inputs driving rail-limited outputs, such as in ADC input stages or video line drivers.

How does the ENABLE pin function on the OPA355NA/3KG4?

The ENABLE pin (Pin 8) controls power state: logic HIGH (≥2 V) enables normal operation with 8.3 mA quiescent current; logic LOW (≤0.8 V) disables the amplifier, reducing current to 3.4 µA and placing the output in high-impedance state. The pin has an internal 100-kΩ pullup to V+, so leaving it open defaults to enabled. Enable and disable times are 100 ns and 30 ns respectively - fast enough for time-division multiplexing. In split-supply use, thresholds reference V–, not ground.

What is the thermal shutdown behavior of the OPA355NA/3KG4?

The OPA355NA/3KG4 incorporates thermal shutdown that activates at 160°C junction temperature, disabling the amplifier to prevent damage. Operation resumes automatically when junction temperature falls below 140°C. This hysteresis prevents oscillation near trip point. The feature protects against sustained overloads, poor heatsinking, or ambient temperature excursions. Thermal resistance is θJA = 125°C/W for the SOIC-8 package, so power dissipation above ~40 mW in still air may trigger shutdown without PCB copper thermal relief.

Can the OPA355NA/3KG4 drive a 50 Ω load effectively?

The OPA355NA/3KG4 is characterized for 150 Ω and 1 kΩ loads, delivering 75 MHz 0.1-dB flatness and 100 MHz small-signal bandwidth at G = 2 into 150 Ω. While it can source ±60 mA continuously (supporting short 50 Ω pulses), sustained 50 Ω driving causes significant output voltage droop and increased distortion due to limited output current and thermal constraints. For robust 50 Ω interface, a dedicated line driver or buffer stage is recommended - the OPA355NA/3KG4 is best applied with ≥100 Ω loads or AC-coupled 50 Ω termination.