ADC

C

VREF

VSS

VDD

5 V

3.3 V

R

OPAx325

Input

+

±150

±125

±100

±75

±50

±25

0

25

50

75

100

125

150

±3

±2

±1

0

1

2

3

V

C003

V

V

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Design

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.

OPA325, OPA2325, OPA4325

SBOS637D – OCTOBER 2016 – REVISED JUNE 2019

OPAx325

Precision, 10-MHz, Low-Noise, Low-Power, RRIO, CMOS Operational Amplifiers

1

1 Features

1

•

Precision with zero-crossover distortion:

–

Low offset voltage: 150 μV (maximum)

–

High CMRR: 114 dB

–

Rail-to-rail I/O

•

Wide bandwidth: 10 MHz

•

Quiescent current: 650 μA/ch

•

Single-supply voltage range: 2.2 V to 5.5 V

•

Low input bias current: 0.2 pA

•

Low noise: 9 nV/

√Hz at 10 kHz

•

Slew rate: 5 V/μs

•

Unity-gain stable

2 Applications

•

High-Z sensor signal conditioning

•

Transimpedance amplifiers

•

Test and measurement equipment

•

Programmable logic controllers (PLCs)

•

Motor control loops

•

Communications

•

Input, output ADC, and DAC buffers

•

Active filters

Offset Voltage vs Input Common-Mode Voltage

3 Description

The OPA325, OPA2325, and OPA4325 (OPAx325)

are precision, low-voltage complementary metal-oxide

semiconductor

(CMOS)

operational

amplifiers

optimized for very low noise and wide bandwidth,

while operating on a low quiescent current of only

650 μA.

The OPAx325 feature a linear input stage with zero-

crossover distortion that delivers excellent common-

mode rejection ratio (CMRR) of typically 114 dB over

the entire input range. The input common-mode

range extends 100 mV beyond the negative and

positive supply rails. The output voltage typically

swings within 10 mV of the rails.

The zero-crossover distortion, combined with wide

bandwidth (10 MHz), high slew rate (5 V/µs), and low

noise (9 nV/

√Hz), make the OPAx325 a very good

successive-approximation register (SAR) analog-to-

digital converter (ADC) input driver amplifier. In

addition, the OPAx325 have a wide supply-voltage

range from 2.2 V to 5.5 V, with excellent power-

supply rejection ratio (PSRR) over the entire supply

range, making the device an excellent choice for

precision, low-power applications that run directly

from batteries without regulation.

The OPA325 (single-channel version) is available in

the SOT23-5 package. The OPA2325 (dual-channel

version) is offered in SO-8 and MSOP-8 packages.

The OPA4325 (quad-channel version) is available in

TSSOP-14 package.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

OPA325

SOT-23 (5)

2.90 mm × 1.60 mm

OPA2325

SOIC (8)

4.90 mm × 3.91 mm

VSSOP (8)

3.00 mm × 3.00 mm

OPA4325

TSSOP (14)

5.00 mm × 4.40 mm

(1) For all available packages, see the package option addendum

at the end of the data sheet.

The OPAx325 as an ADC Driver Amplifier