OPA862 High Input Impedance, Single-Ended to Differential ADC Driver

1 Features

• Wide Supply Range: 3 V to 12.6 V

• High Input Impedance: 325 MΩ

• Voltage Noise:

– Input-Referred (f ≥ 5 kHz): 2.3 nV/√ Hz

– Output-Referred (f ≥ 10 kHz): 8.3 nV/√ Hz

• Differential Output Offset: ±700 µV (Maximum)

• Output Offset Drift: ±1.5 µV/°C (Typical)

• Gain-Bandwidth Product: 400 MHz

• Small-Signal Bandwidth: 44 MHz (G = 2 V/V)

• Slew Rate: 140 V/µs

–122 dBc, –140 dBc

• Rail-to-Rail Output:

– High Linear Output Current: 60 mA (Typical)

• Quiescent Current: 3.1 mA

• Disable mode: 12-µA Quiescent Current

• Extended Temperature Operation:

–40°C to +125°C

2 Applications

• 16-bit and 18-bit ADC Drivers

• Memory and LCD Testers

• Data Acquisition (DAQ)

• Test and Measurement

• Transimpedance Amplifiers (TIA)

• Class-D audio Amplifier Drivers

• Piezoelectric Sensor Interface

• Medical Instrumentation

3 Description

The OPA862 is a single-ended to differential analog-

to-digital converter (ADC) driver with high input

impedance for directly interfacing with sensors. The

device only consumes 3.1-mA quiescent current for

an output-referred noise density of 8.3 nV/√ Hz in a

gain of 2-V/V configuration. A fully differential amplifier

configured in a gain of 1 V/V with 1-kΩ resistors must

be less than 1 nV/√ Hz to achieve the OPA862

equivalent output-referred noise density of

8.3 nV/√ Hz. The OPA862 can be configured for other

gains using external resistors. The device has a large

gain-bandwidth product of 400 MHz and a slew rate of

140 V/µs. This yields exceptional linearity and fast-

settling, 18-bit performance over comparable single-

ended-to-differential ADC drivers. The device includes

a reference input pin for setting the output common-

mode voltage.

The OPA862 is fully characterized to operate over a

wide supply range of 3 V to 12.6 V, and features a

rail-to-rail output stage. The device is fabricated using

Texas Instruments' proprietary, high-speed, silicon-

germanium (SiGe) process and achieves exceptional

distortion performance for 18-bit systems. The device

includes a disable mode that consumes only 12-µA

quiescent current in power-down state.

The OPA862 is rated to work over the extended

industrial temperature range of –40°C to +125°C.

Device Information (1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

OPA862

SOIC (8)

4.90 mm × 3.90 mm

WSON (8)

3.00 mm × 3.00 mm

(1)

For all available packages, see the orderable addendum at

the end of the data sheet.

64.9

64.9

A1

+

±

A2

+

±

700

700

±3.3 V

+7 V

0

OPA862

470 pF

+5 V

ADS8881

2.5 V

470 pF

Single-Ended High-Input Impedance Sensor

Interface

Frequency (Hz)

-160

-150

-140

-130

-120

-110

-100

-90

-80

10k

100k

1M

D017

Harmonic Distortion vs Frequency

www.ti.com

OPA862

SBOS919C – AUGUST 2019 – REVISED AUGUST 2020

Copyright © 2020 Texas Instruments Incorporated

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OPA862

SBOS919C – AUGUST 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.