Texas Instruments OPA1688IDRGR

Overview

OPA1688IDRGR from Texas Instruments is a dual-channel, 36-V, rail-to-rail output audio operational amplifier optimized for high-fidelity signal conditioning in professional audio systems. It delivers –109 dB THD+N at 1 kHz into 32 Ω, 10 MHz gain bandwidth, and 8 nV/√Hz input voltage noise, enabling low-distortion headphone and line-level amplification in compact, single-supply designs.

For engineers reviewing the OPA1688IDRGR datasheet, OPA1688IDRGR pinout, OPA1688IDRGR application, or OPA1688IDRGR equivalent, this device supports critical design decisions in high-voltage audio front-ends, DAC output buffering, and low-noise preamplifier stages where supply flexibility (±2.25 V to ±18 V), EMI resilience, and rail-to-rail output swing are mandatory.

Technical Context

The OPA1688IDRGR implements a three-stage amplifier topology with active feedforward gain staging to achieve 10 MHz bandwidth and 8 V/µs slew rate while maintaining < ±0.25 mV offset and ±0.5 µV/°C drift. Its input stage operates from (V–) – 0.1 V to (V+) – 2 V, with full rail-to-rail input capability beyond the top rail at reduced performance.

EMI filtering is integrated on both inputs, delivering >69 dB EMIRR at 2.4 GHz and >114 dB at 5 GHz-critical for wireless coexistence in A/V receivers and DJ equipment. Phase-reversal protection prevents output inversion when inputs exceed common-mode limits, ensuring robust operation in transient-rich audio signal paths.

Key Specifications

Pinout & Package

OPA1688IDRGR is packaged in an 8-pin WSON (DRG) package measuring 3.00 mm × 3.00 mm with wettable flanks, optimized for automated optical inspection and high-density audio PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA1656IDRGR and OPA1662AIDRGR, the OPA1688IDRGR uniquely balances 10-MHz bandwidth, –109-dB THD+N, integrated EMI filtering, and 36-V operation-making it the optimal choice for cost-sensitive, high-reliability professional audio products requiring single-supply flexibility and co-location with wireless subsystems.

Availability

OPA1688IDRGR is available at Aetrix Electronics and suitable for professional audio mixer design, guitar amplifier signal path conditioning, and A/V receiver preamplifier stages requiring stable component supply and consistent parametric performance across production batches.

Supply support for OPA1688IDRGR 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 precision amplifiers and audio signal chain solutions.

The OPA1688IDRGR belongs to TI's SoundPlus™ audio op amp family, engineered specifically for professional and high-end consumer audio applications demanding ultra-low distortion, wide supply range, and robust EMI immunity in real-world electromagnetic environments.

FAQ

What is the maximum supply voltage for OPA1688IDRGR?

The OPA1688IDRGR supports a maximum supply voltage of 36 V in single-supply mode or ±18 V in dual-supply mode. Absolute maximum ratings specify ±20 V (40 V total), but recommended operating conditions limit continuous use to 36 V to ensure long-term reliability and specified performance across temperature. Exceeding 36 V may degrade THD+N and output swing specifications.

Does OPA1688IDRGR support true rail-to-rail input operation?

The OPA1688IDRGR supports rail-to-rail input operation with a common-mode range extending 100 mV beyond the negative rail and to within 2 V of the positive rail under normal conditions. Full rail-to-rail input (including 100 mV beyond the top rail) is possible but results in reduced performance-specifically increased offset voltage and degraded CMRR-as documented in the datasheet's Section 3 Description.

How does the EMI filtering in OPA1688IDRGR improve system-level audio performance?

The integrated EMI filtering in OPA1688IDRGR provides >69 dB rejection at 2.4 GHz and >114 dB at 5 GHz, directly mitigating interference from Wi-Fi, Bluetooth, and cellular radios. This eliminates audible buzz or modulation artifacts in A/V receivers and DJ equipment without requiring external LC filters or board-level shielding-reducing BOM cost and layout complexity while maintaining THD+N < –109 dB.

Can OPA1688IDRGR be used in DC-coupled phono preamplifier designs?

Yes, OPA1688IDRGR is suitable for DC-coupled phono preamplifier stages due to its ±0.25 mV typical input offset voltage and ±0.5 µV/°C max drift. These parameters ensure minimal DC error accumulation across the high-gain RIAA network (typically 40–60 dB), preventing audible hum or thermal drift in turntable applications operating from –40°C to +85°C.

What is the thermal resistance (RθJA) of the OPA1688IDRGR WSON-8 package?

The OPA1688IDRGR in the DRG (WSON-8) package has a junction-to-ambient thermal resistance (RθJA) of 63.2°C/W under standard JEDEC test conditions. This value assumes a 2-layer PCB with 1-in² copper pour under the exposed pad; actual thermal performance improves with enhanced copper area, internal planes, or thermal vias-critical for sustained 36-V operation in compact audio enclosures.