OPA991, OPA2991, OPA4991
SBOS969E – OCTOBER 2019 – REVISED MAY 2021
OPAx991 40-V Rail-to-Rail Input/Output, Low Offset Voltage, Low Noise Op Amp
1 Features
3 Description
•
•
•
•
•
•
•
•
•
•
Low offset voltage: ±125 µV
The OPAx991 family (OPA991, OPA2991, and
OPA4991) is a family of high voltage (40-V) general
purpose operational amplifiers. These devices offer
exceptional DC precision and AC performance,
including rail-to-rail input/output, low offset (±125 µV,
typ), low offset drift (±0.3 µV/°C, typ), low noise (10.5
nV/√ Hz and 1.8 µVPP), and 4.5-MHz bandwidth.
Low offset voltage drift: ±0.3 µV/°C
Low noise: 10.8 nV/√ Hz at 1 kHz
High common-mode rejection: 130 dB
Low bias current: ±10 pA
Rail-to-rail input and output
Wide bandwidth: 4.5 MHz GBW
High slew rate: 21 V/µs
High capacitive load drive: 1 nF
MUX-friendly/comparator inputs
– Amplifier operates with differential inputs up to
supply rail
– Amplifier can be used in open-loop or as
comparator
Low quiescent current: 560 µA per amplifier
Wide supply: ±1.35 V to ±20 V, 2.7 V to 40 V
Robust EMIRR performance: EMI/RFI filters on
input and supply pins
Differential and common-mode input voltage range
to supply rail
Unique features such as differential and common-
mode input-voltage range to the supply rail, high
output current (±75 mA), high slew rate (21 V/µs),
high capacitive load drive (1 nF), and shutdown
functionality make the OPAx991 a robust, high-
performance operational amplifier for high-voltage
industrial applications.
•
•
•
The OPAx991 family of op amps is available in
micro-size packages (such as X2QFN, WSON, and
SOT-553), as well as standard packages (such as
SOT-23, SOIC, and TSSOP), and is specified from
–40°C to 125°C.
•
Device Information
2 Applications
PART NUMBER (1)
PACKAGE
BODY SIZE (NOM)
2.90 mm × 1.60 mm
2.90 mm × 1.60 mm
2.00 mm × 1.25 mm
4.90 mm × 3.90 mm
2.90 mm × 1.60 mm
3.00 mm × 4.40 mm
3.00 mm × 3.00 mm
2.00 mm × 2.00 mm
2.00 mm × 1.50 mm
8.65 mm × 3.90 mm
5.00 mm × 4.40 mm
3.00 mm × 3.00 mm
2.00 mm × 2.00 mm
•
•
•
•
•
•
•
Low-power audio preamplifier
Multiplexed data-acquisition systems
Test and measurement equipment
ADC driver amplifiers
SAR ADC reference buffers
Programmable logic controllers
High-side and low-side current sensing
SOT-23 (5)
OPA991
SOT-23 (6)
SC70 (5)
SOIC (8)
SOT-23-8 (8)
TSSOP (8)
VSSOP (8)
WSON (8)
X2QFN (10)
SOIC (14)
OPA2991
OPA4991
TSSOP (14)
WQFN (16)(2)
X2QFN (14)
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
(2) Package is preview only.
Analog Inputs
REF3140
RC Filter
OPA375
RC Filter
Bridge Sensor
Thermocouple
Reference Driver
Gain Network
Gain Network
OPA991
+
MUX509
REF
+
OPA991
VINP
Gain Network
Antialiasing
Filter
OPA991
+
ADS8860
Current Sensing
Photo
VINM
Detector
LED
High-Voltage Multiplexed Input
High-Voltage Level Translation
VCM
Optical Sensor
OPAx991 in a High-Voltage, Multiplexed, Data-Acquisition System
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. UNLESS OTHERWISE NOTED, this document contains PRODUCTION
DATA.