OPA1688 - 36V, 10MHz Low Distortion Audio Op Amp | TI
MPN: OPA1688 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.29 | $1.29 |
| 10 | $1.1 | $11.00 |
| 100 | $0.87 | $87.00 |
| 500 | $0.72 | $360.00 |
| 1,000 | $0.58 | $580.00 |
Drop-in alternatives for OPA1688 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
OPA1622
✅ Drop-In📋 Reference alternative (not in catalog)
OPA627
✅ Drop-In✓ In Stock
$7.9 / Unit
View Datasheet →OPA827
✅ Drop-In✓ In Stock
$2.88 / Unit
View Datasheet →OPA2172
⚡ Same Package✓ In Stock
$1.2 / Unit
View Datasheet →OPA1687
⚡ Same Package📋 Reference alternative (not in catalog)
AD8599
✅ Drop-In📋 Reference alternative (not in catalog)
OPA1688 Maximum Ratings & Electrical Characteristics
| Amplifier Type | Audio Operational Amplifier (single) |
| Supply Voltage Range | 4.5 V to 36 V (±2.25 V to ±18 V) |
| Gain Bandwidth Product | 10 MHz |
| Input Voltage Noise Density | 4.5 nV/√Hz |
| Slew Rate | 8 V/µs |
| Quiescent Current | 1.5 mA per amplifier |
| Output Current | ±75 mA |
| Capacitive Load Stability | Up to 1000 pF |
| Input Offset Voltage | 0.5 mV (typical) |
| THD+N | 0.00005% at 1 kHz |
| Output Type | Rail-to-Rail Output |
| Number of Channels | 1 |
| Operating Temperature | -40°C to +85°C |
| Package Options | SOIC-8, WSON-8 |
| Mounting Type | Surface Mount |
OPA1688 Pin Configuration
| Pin 1 | TRIM/N.C. — Offset trim or no connect (package dependent) |
| Pin 2 | IN- — Inverting input |
| Pin 3 | IN+ — Non-inverting input |
| Pin 4 | V- — Negative supply (or GND in single supply) |
| Pin 5 | TRIM/N.C. — Offset trim or no connect (package dependent) |
| Pin 6 | OUT — Rail-to-rail output |
| Pin 7 | V+ — Positive supply (4.5 V to 36 V) |
| Pin 8 | N.C. — No connect (SOIC-8); exposed pad on WSON-8 is V- |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
OPA1688 is suitable for 6 applications: Headphone Amplifiers, Audio DAC Output Buffers, Active Audio Filters, Professional Audio Mixing Consoles, Portable and Battery-Powered Audio, Sensor Signal Conditioning with Audio-Grade Precision.
Headphone Amplifiers
The OPA1688 is explicitly recommended by TI for headphone amplifier circuits thanks to its combination of 4.5 nV/√Hz noise, 0.00005% THD+N at 1 kHz, and ±75 mA output current. In a typical gain stage driving 32 Ω headphones, the rail-to-rail output maximizes swing on 5 V single supplies while the 1000 pF capacitive load stability tolerates headphone cable capacitance directly. Compared with the OPA1622, it runs at only 1.5 mA quiescent current per channel, extending battery life in portable headphone amps.
Recommended
Audio DAC Output Buffers
As an I/V converter or output buffer after audio DACs, the OPA1688's 4.5 nV/√Hz input noise preserves the DAC's dynamic range, and its 10 MHz bandwidth comfortably handles audio-band settling. The ±75 mA drive handles low-impedance line outputs, and 0.00005% THD+N at 1 kHz keeps distortion below audibility thresholds. Its rail-to-rail output allows full-scale signal swing on single-supply 3.3 V or 5 V DAC rails without an external negative supply.
Recommended
Active Audio Filters
Multiple-pole Sallen-Key and multiple-feedback audio filters benefit from the OPA1688's 10 MHz gain-bandwidth, which holds filter corner accuracy at 20 kHz audio frequencies with ample phase margin. The low 0.5 mV typical offset minimizes DC error stacking across cascaded stages, and 1.5 mA quiescent current keeps multi-stage filter power budgets low. Stability with 1000 pF loads permits filter capacitors directly on outputs without isolation resistors.
Recommended
Professional Audio Mixing Consoles
In mixing console line inputs, summing amps, and output drivers, the OPA1688 offers the low noise (4.5 nV/√Hz) and wide 36 V supply range needed for high-headroom professional +24 dBu signal levels on ±18 V rails. THD+N of 0.00005% ensures channel-to-channel crosstalk artifacts stay inaudible, while ±75 mA output current drives long console cabling. Its SoundPlus family consistency simplifies sourcing one op amp across many circuit positions.
Recommended
Portable and Battery-Powered Audio
With 1.5 mA quiescent current per channel and operation down to 4.5 V single supply, the OPA1688 suits battery-powered recorders, Bluetooth speakers, and portable players. The rail-to-rail output extracts maximum swing from a depleting battery, and 1000 pF load stability tolerates cable capacitance in headphone jacks. Compared with higher-power audio drivers like the OPA1622, it sacrifices output current for roughly an order-of-magnitude longer battery runtime.
Recommended
Sensor Signal Conditioning with Audio-Grade Precision
Beyond audio, the OPA1688's 36 V supply tolerance, 0.5 mV offset, and low noise suit conditioning microphone, ultrasonic, and vibration sensors in industrial monitoring. Its 8 V/µs slew rate handles fast transient signals, and -40°C to +85°C operation covers factory environments. Single-supply 24 V industrial rails can be used directly without a dual supply, reducing BOM cost versus ±15 V legacy analog front ends.
Recommended
Recommended Products Summary
Engineering reference data for OPA1688 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | OPA1622 | OPA2172 | AD8599 |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Package | SOIC-8 / WSON-8 | SOIC-8 | SOIC-8 (dual pinout) | SOIC-8 |
| Channels | 1 | 1 | 2 | 1 |
| Supply Range | 4.5 V to 36 V | [DATA_NEEDED] | 4.5 V to 36 V | 2.7 V to [DATA_NEEDED] |
| Output Current | ±75 mA | Higher than OPA1688 | Lower than OPA1688 | [DATA_NEEDED] |
| Noise Density | 4.5 nV/√Hz | Comparable (family) | Comparable | [DATA_NEEDED] |
| Quiescent Current | 1.5 mA/ch | Higher | [DATA_NEEDED] | [DATA_NEEDED] |
| Capacitive Load Stability | 1000 pF | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- Lowest quiescent current in class (vs OPA1622)
- Higher output current than dual-channel parts (vs OPA2172)
- 1000 pF capacitive load stability (vs AD8599)
Design Notes
Place 0.1 µF ceramic decoupling capacitors within 2 mm of the V+ and V- pins, plus a 2.2-10 µF bulk capacitor per supply rail. Use a solid ground plane under the amplifier and keep the feedback resistor network traces short and direct to minimize parasitic capacitance at the inverting node, which can erode phase margin and increase distortion at 20 kHz.
Although the OPA1688 is stable with up to 1000 pF of capacitive load, driving heavier loads (long cables, MOSFET gates) requires a series isolation resistor of 10-50 Ω at the output. Place the resistor inside the feedback loop after the sense point when DC accuracy at the load matters, to avoid degrading output offset and gain accuracy.
Do not exceed the 36 V (±18 V) absolute maximum supply. For single-supply operation near 4.5 V, verify input common-mode range in your configuration: the OPA1688 input is not rail-to-rail, so reference the input signal above ground using bias networks as shown in the TI datasheet typical applications. In gain configurations below gain of 1 buffer stability, check noise-gain compensation.
Compliance Information
SOIC-8 and WSON-8 packages listed as production data by TI. Detailed REACH/halogen declarations available via TI quality portal.
