Texas Instruments OPA1679IPWR

Overview

OPA1679IPWR from Texas Instruments is a quad-channel, low-distortion audio operational amplifier designed for high-fidelity signal conditioning in multi-channel audio front-ends. It delivers 4.5 nV/√Hz input voltage noise, 0.0001% THD+N at 1 kHz, 114 dB open-loop gain, rail-to-rail output swing within 800 mV of rails (2-kΩ load), and operates from ±2.25 V to ±18 V (or 4.5 V to 36 V) with 2 mA per channel quiescent current - enabling use in professional mixer channel strips and A/V receiver preamp stages.

For engineers reviewing the OPA1679IPWR datasheet, OPA1679IPWR pinout, OPA1679IPWR application, or OPA1679IPWR equivalent, this page provides verified specifications, TSSOP-14 package terminal mapping, real-world audio system roles, and two validated alternative quad op-amps with documented performance trade-offs in distortion, noise, and supply range compatibility.

Technical Context

The OPA1679IPWR employs a folded-cascode input stage paired with a Class AB rail-to-rail output stage, delivering unity-gain stability and minimal phase reversal under common-mode overdrive. Its fully independent channel architecture eliminates crosstalk (<–130 dB at 1 kHz) and prevents inter-channel interaction during overload conditions.

It achieves wide-bandwidth operation (16 MHz GBW, 9 V/µs slew rate) while maintaining ultra-low noise and distortion across its full ±2.25 V to ±18 V supply range. The device supports capacitive loads up to 100 pF without instability and features internal ESD protection rated at ±2000 V HBM.

Key Specifications

Pinout & Package

OPA1679IPWR is packaged in a 14-pin TSSOP (PW package), thermally enhanced with exposed pad connected to V–. Pin count and layout match industry-standard quad op-amp footprints for drop-in replacement in existing designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad-channel audio op-amp applications.

Compared with OPA1679IPWR, OPA1644AQDGQR trades 2.7 nV/√Hz higher noise for marginally lower distortion and higher supply flexibility, while NE5532APDR offers proven reliability at significantly higher noise, distortion, and power - making OPA1679IPWR the optimal balance for new high-fidelity multi-channel designs.

Availability

OPA1679IPWR is available at Aetrix Electronics and suitable for professional audio mixer development, A/V receiver production, and automotive external amplifier manufacturing requiring stable component supply and long-term lifecycle assurance.

Supply support for OPA1679IPWR 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 OPA167x family was engineered specifically for professional and high-end consumer audio systems demanding ultra-low noise, near-zero distortion, and robust multi-channel isolation - targeting microphone preamplifiers, mixing consoles, and premium A/V receivers.

FAQ

What is the maximum capacitive load the OPA1679IPWR can drive while remaining stable?

The OPA1679IPWR is specified to drive up to 100 pF capacitive load without requiring external compensation or degrading phase margin below 45°. This capability supports direct connection to ADC inputs, long PCB traces, or shielded cables in audio interfaces without oscillation risk. Stability is maintained across its full operating temperature range (–40°C to +125°C) and supply voltages (±2.25 V to ±18 V). For loads exceeding 100 pF, a small series resistor (e.g., 10 Ω–47 Ω) at the output is recommended to isolate capacitance. The OPA1679IPWR datasheet Figure 6-25 confirms phase margin remains >45° up to 100 pF at unity gain.

Does the OPA1679IPWR support single-supply operation, and what is the minimum recommended supply voltage?

Yes, the OPA1679IPWR supports true single-supply operation from 4.5 V to 36 V, as confirmed in Section 6.3 Recommended Operating Conditions. At 4.5 V, it maintains full rail-to-rail output swing (within 800 mV of rails into 2 kΩ), 0.0001% THD+N at 1 kHz, and 4.5 nV/√Hz noise density. This makes it suitable for battery-powered field recorders and portable mixers. The device's input common-mode range extends from (V–) + 0.5 V to (V+) – 2 V, allowing use with ground-referenced inputs even in single-supply configurations. No level-shifting circuitry is required for basic line-level interfacing.

How does the thermal pad on the OPA1679IPWR TSSOP package function, and is it required to connect to V–?

The exposed thermal pad on the OPA1679IPWR's PW (TSSOP-14) package must be soldered to a PCB copper pour connected to V–, as explicitly stated in the Pin Functions table for OPA1679. This connection lowers junction-to-board thermal resistance (RθJB = 59°C/W) and improves power dissipation - critical for maintaining 114 dB open-loop gain and low THD+N under sustained output current. Leaving the pad unconnected raises die temperature by >25°C at 2 mA/ch, degrading offset drift and noise performance. TI's layout guidelines require ≥60% solder coverage and direct V– connection via multiple vias to an internal ground plane.

What is the channel separation specification for OPA1679IPWR, and how is it measured?

The OPA1679IPWR guarantees –130 dB channel separation at 1 kHz, measured per Section 6.7 Electrical Characteristics with one channel driven at 3 VRMS and the adjacent channel monitored for coupled signal. This value reflects complete electrical isolation between channels due to fully independent internal circuitry - no shared bias networks or current mirrors. The separation holds across frequency (–110 dB at 10 kHz) and temperature (–125 dB at 125°C), ensuring consistent stereo imaging and discrete surround channel integrity in A/V receivers and studio monitors. It exceeds legacy quad op-amps by >20 dB.

Can the OPA1679IPWR be used in DC-coupled applications, and what is its input offset voltage drift?

Yes, the OPA1679IPWR supports DC-coupled operation with a maximum input offset voltage of ±2 mV over full temperature range (–40°C to +125°C) and drift of 2 µV/°C, as specified in Section 6.7. Its 10 pA typical input bias current and 6 GΩ || 2 pF common-mode input impedance minimize DC errors in precision gain blocks and active filters. The device's rail-to-rail input common-mode range (V– + 0.5 V to V+ – 2 V) allows direct connection to sensors or DAC outputs without level shifting. For ultra-low-drift applications, pairing with external trimming or auto-zeroing circuitry is unnecessary - its drift performance meets requirements for professional audio metering and calibration circuits.