OPA1637 High-Fidelity, Low-Noise, Fully-Differential, Burr-Brown™ Audio

Operational Amplifier

1 Features

• Low input voltage noise: 3.7 nV/√Hz at 1 kHz

• Low THD + N: –120 dB at 1 kHz

• Low supply current: 950 µA at ±18 V

• Input offset voltage: ±200 µV (maximum)

• Input bias current: 2 nA (maximum)

• Low bias current noise: 400 fA/√Hz at 10 Hz

• Gain-bandwidth product: 9.2 MHz

• Differential output slew rate: 15 V/µs

• Wide input and output common-mode range

• Wide single-supply operating range: 3 V to 36 V

• Low supply current power-down feature: < 20 µA

• Overload power limit

• Current limit

• Package: 8-pin VSSOP

• Temperature range: –40°C to +125°C

2 Applications

• Professional audio mixer or control surface

• Professional microphones and wireless systems

• Professional speaker systems

• Professional audio amplifier

• Soundbar

• Turntable

• Professional video camera

• Guitar and other instrument amplifier

• Data aquisition (DAQ)

3 Description

The OPA1637 is a low-noise, low total harmonic

distortion (THD), fully differential, Burr-Brown™ Audio

operational amplifier that easily filters and drives fully

differential, audio signal chains.

The OPA1637 also converts single-ended sources to

differential outputs required by high-fidelity analog-to-

digital converters (ADCs). Designed for exceptional

low noise and THD, the bipolar super-beta inputs yield

a very low noise figure at very-low quiescent current

and input bias current. This device is designed for

audio circuits where low power consumption is

required along with excellent signal-to-noise ratio

(SNR) and spurious-free dynamic range (SFDR).

The OPA1637 features high-voltage supply capability,

allowing for supply voltages up to ±18 V. This

capability allows high-voltage differential signal chains

to benefit from the improved headroom and dynamic

range without adding separate amplifiers for each

polarity of the differential signal. Very-low voltage and

current noise enables the OPA1637 for use in high-

gain configurations with minimal impact to the audio

signal noise.

The OPA1637 is characterized for operation over the

wide temperature range of –40°C to +125°C, and is

available in an 8-pin VSSOP package.

Device Information (1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

OPA1637

VSSOP (8)

3.00 mm × 3.00 mm

(1)

For all available packages, see the package option

addendum at the end of the datasheet.

+

±

5 V

+

±

OPA1637

PD

RISO1

75

RISO2

75

RF1

1 k

CF1

3.3 nF

CF2

3.3 nF

RF2

1 k

CDF

10 nF

ADC

C2

1 µF

C3

1 µF

5 V

±10 V

C5

1 µF

PCM1795

Audio DAC

TPA3251

Class D

Amplifier

± 3.5 V

±10 V 5 V

GND

GND

IOUTL/R+

IOUTL/R±

INPUT_A

INPUT_B

RI2

49

RI1

49

Low-Noise, Low-Power, Fully-Differential Amplifier

Gain Block and Interface

Frequency (Hz)

1

2

3

5

7

10

20

30

50

70

100

100m

1

10

100

1k

10k

100k

D022

Low Input Voltage Noise

www.ti.com

OPA1637

SBOSA00B – DECEMBER 2019 – REVISED AUGUST 2020

Copyright © 2020 Texas Instruments Incorporated

Submit Document Feedback

1

Product Folder Links: OPA1637

OPA1637

SBOSA00B – DECEMBER 2019 – REVISED AUGUST 2020

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.