6 Detailed Description

6.1 Overview

The OPAx397 is a family of low offset, low-noise e-trim operational amplifiers (op amps) that uses a proprietary

offset trim technique. These op amps offer ultra-low input offset voltage and drift and achieve excellent input and

output dynamic linearity. The OPAx397 operate from 1.7V to 5.5V, are unity-gain stable, and are designed for a

wide range of general-purpose and precision applications.

The amplifiers feature state-of-the-art CMOS technology and advanced design features that help achieve

extremely low input bias current, wide input and output voltage ranges, high loop gain, and low, flat output

impedance in small package options. The OPAx397 strengths also include 13MHz bandwidth, 4.4nV/√Hz noise

spectral density, and low 1/f noise. These features make the OPAx397 an exceptional choice for interfacing with

sensors, photodiodes, and high-performance analog-to-digital converters (ADCs).

6.2 Functional Block Diagram

V

BIAS1

BIAS1

V

BIAS2

BIAS2

+IN

±IN

Class AB

Class AB

Control

Control

Circuitry

Circuitry

OUT

OUT

Ví

Ví

(Ground)

(Ground)

V+

V+

Reference

Reference

Current

Current

OPA397, OPA2397, OPA4397

SBOSA02A – AUGUST 2021 – REVISED APRIL 2025

www.ti.com

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