Texas Instruments OPA1604AID

Overview

OPA1604AID from Texas Instruments is a quad-channel, bipolar-input audio operational amplifier optimized for ultra-low-noise, ultra-low-distortion signal conditioning in professional audio front-ends and precision analog playback paths. It delivers 2.5nV/√Hz input voltage noise density, 0.00003% THD+N at 1kHz, 20V/μs slew rate, and rail-to-rail output swing within 600mV of supply rails into 2kΩ - enabling high-fidelity headphone drivers and line-level preamplifier stages.

For engineers reviewing the OPA1604AID datasheet, OPA1604AID pinout, OPA1604AID application, or OPA1604AID equivalent, this page provides verified electrical specifications, SO-14 package layout, dual-supply design guidance (±2.25V to ±18V), channel separation performance (–130dB at 1kHz), and real-world audio system integration constraints including capacitive load isolation and input protection limits.

Technical Context

The OPA1604AID employs fully independent bipolar input circuitry per channel to eliminate crosstalk and maintain stability under overdrive or overload conditions. Its unity-gain stable architecture supports noninverting, inverting, and buffer configurations without external compensation.

It features matched internal transistor pairs for low offset voltage (±0.1mV typical), high open-loop gain (120dB), and wide bandwidth (35MHz GBW at G = +1), while maintaining ultralow distortion across the full audio band (20Hz–20kHz) with 3VRMS output into 2kΩ.

Key Specifications

Pinout & Package

OPA1604AID is housed in a 14-pin SOIC (SO-14) package with standard 1.27mm pitch, compatible with automated PCB assembly and thermal management via exposed copper pour under the body.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar audio operational amplifier applications.

Compared with OPA1604AID, OPA1612AIDR offers superior noise performance but sacrifices channel count and increases power draw, while NE5532AP trades significant audio fidelity for broader legacy compatibility and lower unit cost - making OPA1604AID the optimal balance of quad-channel density, studio-grade linearity, and thermal efficiency in new high-fidelity designs.

Availability

OPA1604AID is available at Aetrix Electronics and suitable for professional audio equipment, broadcast studio infrastructure, and high-end A/V receivers requiring stable component supply with guaranteed long-term manufacturability and TI's extended product lifecycle support.

Supply support for OPA1604AID 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 leadership in high-performance audio signal chain components.

The OPA1604AID belongs to TI's SoundPlus™ audio op amp family, engineered specifically for professional and consumer audio systems demanding vanishingly low noise, distortion, and crosstalk across full temperature and supply ranges.

FAQ

What is the maximum capacitive load the OPA1604AID can drive without oscillation?

The OPA1604AID requires isolation from capacitive loads exceeding 100pF. When driving >100pF (e.g., long cables or ADC input capacitance), a 50Ω series resistor must be placed between OUTx and the load. This maintains phase margin and prevents overshoot or ringing, as confirmed by Figure 19 in the SBOS474B datasheet. The OPA1604AID itself does not include internal isolation; external RC damping is mandatory for stability.

Does the OPA1604AID support single-supply operation?

Yes, the OPA1604AID operates from a single supply (e.g., +5V to +36V total) provided the input common-mode voltage remains within (V–) + 2V to (V+) – 2V and output swing stays within the rail-to-rail limits. For example, with +12V and GND rails, inputs must stay between 2V and 10V, and outputs swing from 0.6V to 11.4V into 2kΩ. Decoupling and reference biasing must be implemented per Section 8.2.2 of the datasheet.

How does the OPA1604AID handle input overvoltage conditions?

The OPA1604AID integrates back-to-back input diodes that clamp differential input voltage to ±0.7V. If an input ramp exceeds the amplifier's slew rate, these diodes conduct - limiting current to 10mA maximum. Exceeding this risks damage. TI recommends adding a series input resistor (RI) to enforce this limit, especially in unity-gain buffer configurations with fast-rising signals, as detailed in Figure 32 and Section 8.3.1.

Is the OPA1604AID pin-compatible with other TI quad op amps like the OPA4134?

No, the OPA1604AID is not pin-compatible with OPA4134 or OPA4227. Its SO-14 pinout (with dedicated V–, NC, and four full channel sets) differs from the OPA4134's 14-pin layout (which uses pins 4 and 11 for V– and V+, respectively, and lacks NC). Substitution requires PCB redesign. Always verify pin mapping against the specific package drawing - OPA1604AID uses TI's SO-14 "D" package marking "O1604A".

What thermal considerations apply to the OPA1604AID in continuous operation?

At ±15V supply and full output swing into 2kΩ, the OPA1604AID dissipates ~180mW per channel. Its SO-14 θJA is 92.8°C/W, so junction temperature rise is ~16.7°C above ambient. To maintain reliability, keep ambient ≤70°C and use ≥1cm² copper pour under the IC. Avoid placing heat sources nearby, and confirm thermal performance using TI's thermal metrics report SPRA953 - especially ψJB (39.3°C/W) for board-level conduction.