OPAx863A High-Precision, 105-MHz, Rail-to-Rail Input/Output Amplifiers

1 Features

• Gain-bandwidth product: 50 MHz

• High precision

– Input offset voltage: 95 µV (maximum)

– Offset drift: 1.2 µV/°C (maximum)

• Low power

– Quiescent current: 800 µA/ch (typical)

– Supply voltage: 2.7 V to 12.6 V

• Input voltage noise: 6.3 nV/√Hz

• Slew rate: 100 V/µs

• Rail-to-rail input and output

• HD2 and HD3: –129 dBc and –138 dBc at 20 kHz

(2-VPP)

• Operating temperature range:

–40°C to +125°C

• Additional features:

– Overload power limit

– Output short-circuit protection

2 Applications

• Low-power SAR and ΔΣ ADC driver

• ADC reference buffer

• Low-side current sensing

• Photodiode TIA interface

• Inductive sensing

• Battery-powered instrumentation

• Gain and active filter stages

3 Description

The OPA863A and OPA2863A devices (OPAx863A)

are low-power, unity-gain stable, rail-to-rail input

and output, voltage-feedback operational amplifiers.

These devices are trimmed in package to offer high-

precision performance with a maximum input offset

voltage of 95 μV and offset drift of 1.2 μV/

℃ for high

accuracy measurements over temperature.

Consuming only 800 µA per channel, the OPAx863A

offer a gain-bandwidth product of 50 MHz, slew rate of

100 V/µs, and a voltage noise density of 6.3 nV/√Hz.

The rail-to-rail input stage with 2.7-V supply operation

is useful in portable, battery-powered applications.

The rail-to-rail input stage is well matched for gain-

bandwidth product and noise across the full input

common-mode voltage range, enabling excellent

performance with wide-input dynamic range.

The OPAx863A include overload power limiting to limit

the increase in IQ with saturated outputs, thereby

preventing excessive power dissipation in power-

conscious, battery-operated systems. The output

stage is short-circuit protected, making these devices

conducive to ruggedized environments.

Device Information

PART NUMBER(1)

CHANNEL COUNT

PACKAGE(2)

OPA863A

Single

DBV (SOT-23, 5)

OPA2863A

Dual

DSN (USON, 10)

(1)

See the Device Comparison Table.

(2)

For more information, see Section 11.

ADS7057

14-bit

2.5 MSPS

R

S

+

–

3.3 V

AVDD

OPAx863A

C

CB

C

FILT

REF1933

3.3-V

Reference

5V

R

F

R

G

Z

OUT

Sensor

3.3 V

R

S

OPAx863A as a Precision SAR ADC Input Driver

Input Offset Drift (

V/C)

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

0

4

8

12

16

20

Precision Performance With Low Input-Offset-

Voltage Drift

OPA863A, OPA2863A

SBOSA95D – MAY 2022 – REVISED DECEMBER 2023

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.