1 Features
• Low noise: 4.5 nV/√Hz at 1 kHz
• Low distortion: 0.0001% at 1 kHz
• High open-loop gain: 114 dB
• High common-mode rejection: 110 dB
• Low quiescent current:
– 2 mA per channel
• Low input bias current: 10 pA (typical)
• Slew rate: 9 V/μs
• Wide gain bandwidth: 16 MHz (G = 1)
• Unity-gain stable
• Rail-to-rail output
• Wide supply range:
– ±2.25 V to ±18 V, or 4.5 V to 36 V
• Single, dual, and quad-channel versions
• Available packages:
– Single: SOIC-8, SOT-23
– Dual: SOIC-8, small SON-8, VSSOP-8
– Quad: Small QFN-16, SO-14, TSSOP-14
• Temperature range: –40°C to +85°C

2 Applications
• Professional microphones and wireless systems
• Professional audio mixer/control surface
• Guitar amplifier and other music instrument
amplifier
• A/V receiver
• Automotive external amplifier

3 Description
The single-channel OPA1677, dual-channel
OPA1678, and quad-channel OPA1679 (OPA167x)
op amps offer higher system-level performance over
legacy op amps commonly used in audio circuitry.
The OPA167x amplifiers achieve a low 4.5-nV/√Hz
noise density and low distortion of 0.0001% at 1 kHz,
which improves audio signal fidelity. These devices
also offer rail-to-rail output swing to within 800 mV
with a 2-kΩ load, which increases headroom and
maximizes dynamic range.
To accommodate the power-supply constraints of
many types of audio products, the OPA167x operate
over a very-wide supply range of ±2.25 V to ±18 V
(or 4.5 V to 36 V) on only 2 mA of supply current.
These op amps are unity-gain stable and have
excellent dynamic behavior over a wide range of load
conditions, allowing the OPA167x to be used in many
audio circuits.
The OPA167x amplifiers use completely independent
internal circuitry for lowest crosstalk and freedom from
interactions between channels, even when overdriven
or overloaded.