OPA2991IDSGR datasheet(32/78 Pages) TI

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8 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

8.1 Application Information

The OPAx991 family offers excellent DC precision and AC performance. These devices operate up to 40-V

supply rails and offer true rail-to-rail input/output, low offset voltage and offset voltage drift, as well as 4.5-MHz

bandwidth and high output drive. These features make the OPAx991 a robust, high-performance operational

amplifier for high-voltage industrial applications.

8.2 Typical Applications

8.2.1 Low-Side Current Measurement

Figure 8-1 shows the OPA991 configured in a low-side current sensing application. For a full analysis of the

circuit shown in Figure 8-1 including theory, calculations, simulations, and measured data, see TI Precision

Design TIPD129, 0-A to 1-A Single-Supply Low-Side Current-Sensing Solution.

–

7.5 k

LOAD

360 k

LM7705

5 V

OUT

SHUNT

OPA991

100 m

Figure 8-1. OPA991 in a Low-Side, Current-Sensing Application

8.2.1.1 Design Requirements

The design requirements for this design are:

• Load current: 0 A to 1 A

• Output voltage: 4.9 V

• Maximum shunt voltage: 100 mV

OPA991, OPA2991, OPA4991

SBOS969F – OCTOBER 2019 – REVISED JANUARY 2022

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Product Folder Links: OPA991 OPA2991 OPA4991

OPA2991IDSGR Datasheet(PDF) 32 Page - Texas Instruments