1 Features
1• Superior Sound Quality
• True JFET Input Operational Amplifier
With Low Input Bias Current
• Low Noise: 5.1 nV/√Hz at 1 kHz
• Ultralow Distortion: 0.00005% at 1 kHz
• High Slew Rate: 20 V/μs
• Unity Gain Stable
• No Phase Reversal
• Low Quiescent Current:
1.8 mA per Channel
• Rail-to-rail Output
• Wide Supply Range: ±2.25 V to ±18 V
• Single, Dual, and Quad Versions Available

2 Applications
• Professional Audio Equipment
• Analog and Digital Mixing Consoles
• Broadcast Studio Equipment
• High-End A/V Receivers
• High-End Blu-ray™ Players

3 Description
The OPA1641 (single), OPA1642 (dual), and
OPA1644 (quad) series are JFET-input, ultralow
distortion, low-noise operational amplifiers fully
specified for audio applications.
The OPA1641, OPA1642, and OPA1644 rail-to-rail
output swing allows increased headroom, making
these devices ideal for use in any audio circuit.
Features include 5.1-nV/√Hz noise, low THD+N
(0.00005%), a low input bias current of 2 pA, and low
quiescent current of 1.8 mA per channel.
These devices operate over a very wide supply
voltage range of ±2.25 V to ±18 V. The OPA1641,
OPA1642, and OPA1644 series of operational
amplifiers are unity-gain stable and provide excellent
dynamic behavior over a wide range of load
conditions.
The dual and quad versions feature completely
independent circuitry for lowest crosstalk and
freedom from interactions between channels, even
when overdriven or overloaded.
The OPA1641, OPA1642, and OPA1644 are
specified from –40°C to +85°C. SoundPlus™