7 Detailed Description

7.1 Overview

The OPAx376-Q1 family belongs to a new generation of low-noise e-trim operational amplifiers, giving

customers outstanding dc precision and ac performance. Low noise, rail-to-rail input and output, low offset,

and drawing a low quiescent current, make these devices an excellent choice for a variety of precision and

portable applications. In addition, these devices have a wide supply range with excellent PSRR, making the

OPAx376-Q1 a great option for applications that are battery powered without regulation.

7.2 Functional Block Diagram

e-trim

POR

OUT

V+

V-

-IN

+IN

OPAx376

7.3 Feature Description

The OPAx376-Q1 family of precision amplifiers offers excellent dc performance as well as excellent ac

performance. Operating from a single power-supply the OPAx376-Q1 is capable of driving large capacitive

loads, has a wide input common-mode voltage range, and is well-suited to drive the inputs of successive-

approximation response (SAR) analog-to-digital converters (ADCs) as well as 24-bit and higher resolution

converters. Including internal ESD protection, the OPAx376-Q1 family is offered in a variety of industry-standard

packages, including a wafer chip-scale package for applications that require space savings.

7.3.1 Operating Voltage

The OPAx376-Q1 family of amplifiers operate over a power-supply range of 2.2 V to 5.5 V (±1.1 V to ±2.75 V).

Many of the specifications apply from –40°C to +125°C. Parameters that can exhibit significant variance with

regard to operating voltage or temperature are presented in Section 6.8.

7.3.2 Input Offset Voltage and Input Offset Voltage Drift

The OPAx376-Q1 family of e-trim operational amplifiers is manufactured using TI's proprietary trim technology,

a method of trimming internal device parameters during either wafer probing or final testing. Each amplifier is

trimmed in production, thereby minimizing errors associated with input offset voltage and input offset voltage

drift.

7.3.3 Capacitive Load and Stability

The OPAx376-Q1 series of amplifiers may be used in applications where driving a capacitive load is required.

As with all op amps, there may be specific instances where the OPAx376-Q1 can become unstable, leading to

oscillation. The particular op amp circuit configuration, layout, gain, and output loading are some of the factors

to consider when establishing whether an amplifier is be stable in operation. An op amp in the unity-gain (1 V/V)

buffer configuration and driving a capacitive load exhibits a greater tendency to be unstable than an amplifier

operated at a higher noise gain. The capacitive load, in conjunction with the op amp output resistance, creates a

pole within the feedback loop that degrades the phase margin. The degradation of the phase margin increases

as the capacitive loading increases.

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OPA376-Q1, OPA2376-Q1, OPA4376-Q1

SBOS549C – APRIL 2011 – REVISED MARCH 2021

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Product Folder Links: OPA376-Q1 OPA2376-Q1 OPA4376-Q1