If the device then begins to drive a heavy load, the junction temperature can rise and trip the thermal-shutdown

circuit. Figure 7-9 shows the maximum output voltage versus ambient temperature to avoid exceeding the

Absolute Maximum Ratings in both loaded and unloaded conditions for the SOT23-5 package version of the

OPA591. The curve assumes a typical quiescent current and does not account for any temperature variation of

quiescent current.

7.4.1.2 Creepage and Clearance

When designing and building electrical systems with high voltage, two important concepts to consider are

creepage and clearance. Creepage distance refers to the shortest path that an electric current can take along

the surface of an insulating material, such as a printed circuit board (PCB) or a plastic enclosure. Clearance

distance refers to the shortest distance between two conductive parts, such as wires, terminals, or components,

through the air. Figure 7-11 illustrates creepage and clearance for a typical integrated circuit (IC).

```

PCB

Integrated Circuit

Creepage distance

Clearance distance

Groove

Creepage

Integrated Circuit

PCB

High

Voltage

PCB trace

Potentially

Low Voltage

PCB Trace

Creep

age

High

Voltage

Differentia

l Between

V+ and

V

Top view

Edge View

Creepage

and

Clearance

Figure 7-11. Creepage and Clearance in Integrated Circuits

Several standards exist with creepage and clearance guidance, but how the standards pertain to operational

amplifiers and other integrated circuits is largely left to interpretation and internal requirements. The guidance

distances are significantly affected by pollution degree, maximum voltage, and the underlying application. In

the case of creepage, the comparative tracking index (CTI) rating of the insulating material is a major factor.

Different design techniques exist to improve creepage and clearance if deemed necessary, including adding

PBC grooves, conformal coating, and, or derating the operating voltage.

Texas Instruments offers modern packaging with small dimensions that are designed to minimize PCB area.

However, the requirement to meet any creepage or clearance specifications depends on the designer’s

interpretation and implementation of any relevant IEC or system-level standards. For more information on this

topic, visit the Demystifying Clearance and Creepage Distance for High-Voltage End Equipment document.

www.ti.com

OPA591, OPA2591

SBOSA47A – FEBRUARY 2026 – REVISED SEPTEMBER 2026

Copyright © 2026 Texas Instruments Incorporated

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