INA791A datasheet(28/40 Pages) TI2

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7.4 Layout Example

Alert

IS+

IN+

GND

REF

OUT

Place vias connecting to inner or bottom

layers as close as possible to the device.

The number of vias required depends on

operational current and ambient conditions

Device Bypass Capcitor

TI Device

Adjustable Gain

Resistors

Figure 7-10. INA791x Layout Example

7.5 Layout Guidelines

• This device is specified for current handling of up to 50A over the entire –40°C to +125°C temperature range

using a 2oz copper pour for the input power plane, as well as no external airflow passing over the device.

• The primary current-handling limitation for this device is how much heat is dissipated inside the package.

Efforts to improve heat transfer out of the package and into the surrounding environment improve the ability

of the device to handle currents of up to 50A over a wider temperature range.

• Heat transfer improvements primarily involve larger copper power traces and planes with increased copper

thickness (2oz.), as well as providing airflow to pass over the device. Thermal vias help spread the current

and power dissipated over multiple board layers. The INA791x evaluation module (EVM) features a 2oz

copper pour for the planes, and is capable of supporting 50A at temperatures up to 125°C.

• The bypass capacitor must be placed close to device ground and supply pins, but can be moved farther out if

needed to avoid cutting thermal planes. The recommended value of this bypass capacitor is 0.1µF. Additional

decoupling capacitance can be added to compensate for noisy or high-impedance power supplies.

INA791A, INA791B

SBOSAD1A – MAY 2024 – REVISED JULY 2025

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INA791A Datasheet(PDF) 28 Page - Texas Instruments