Dual op-amp tuned for audio: low input voltage noise, low total harmonic distortion, and a rail-to-rail output, on a modest 2.25 to 5.5 V single supply. That makes it a good active filter, line driver, and headphone-buffer front end for portable and line-level audio where a classic NE5532 needs more supply and headroom. Both amplifiers share the standard dual SOIC-8 pinout. A low-cost, low-distortion audio dual for battery and single-supply designs.

Pinout

Pin	Name	Type	Function
1	OUT A	output	Output of channel A op-amp. Rail-to-rail output stage swings within 800 mV of the supply rails into a 2-kΩ load.
2	-IN A	input	Inverting input of channel A op-amp. High-impedance input, typical input bias current 10 pA.
3	+IN A	input	Noninverting input of channel A op-amp. High-impedance input, typical input bias current 10 pA.
4	V-	power_in	Negative (lowest) power supply. Operates from -18 V to 0 V in split-supply mode or tied to GND in single-supply operation (total supply 4.5 V to 36 V).
5	+IN B	input	Noninverting input of channel B op-amp. High-impedance input, typical input bias current 10 pA.
6	-IN B	input	Inverting input of channel B op-amp. High-impedance input, typical input bias current 10 pA.
7	OUT B	output	Output of channel B op-amp. Rail-to-rail output stage swings within 800 mV of the supply rails into a 2-kΩ load.
8	V+	power_in	Positive (highest) power supply. ±2.25 V to ±18 V split, or 4.5 V to 36 V single-supply with V- at GND. Quiescent current ~2 mA per channel.

Key specifications

Parameter	Value
Type	Dual audio op-amp
Input noise	4.5 nV/rtHz
THD+N	0.00006% (typ)
Gain-bandwidth	16 MHz
Output	Rail-to-rail
Supply	2.25-5.5 V
Package	SOIC-8

Ordering variants

Same part, different packaging or reel option.

OPA1678IDR (SOIC-8)
OPA1678IDGKR (VSSOP-8)
OPA1679IDR (quad, SOIC-14)

CAD (KiCad official)

Symbol: Amplifier_Operational:OPA1678 (KiCad official)
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Texas Instruments datasheet (56 pp, sha256 4072daad4ebc4ec9, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF