INA849 datasheet(32/52 Pages) TI

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9.1.4 Thermal Effects due to Power Dissipation

The INA851 dissipates approximately 180 mW of power under quiescent conditions at a ±15-V supply voltage.

The internal resistor network and output load drive causes an additional power dissipation that depends on

the input signal. The small silicon area of the INA851 causes the internal circuitry to experience temperature

gradients that can adversely affect the electrical performance.

Precision parameters, such as offset voltage, linearity, common-mode rejection ratio, and total harmonic

distortion, can be impacted as a result of these thermal effects in the silicon. The thermal gradient particularly

affects the performance of low-frequency input signals with higher gains (> 10) and large output voltage

variation. Figure 9-2 shows that the thermal effect can be minimized by lowering the supply voltage, if the

application permits.

To properly dissipate heat from the INA851, connect the thermal pad with sufficient thermal vias to a large

copper plane that is connected to the negative supply, VS–. A thorough PCB layout is of key importance (see

also Section 9.4).

Output Voltage (V)

-8

-6

-4

-2

-300

-250

-200

-150

-100

-50

100

150

200

250

300

350

400

450

500

VS =

Figure 9-2. Linearity vs Supply Voltage for G = 1000

INA851

SBOS999A – MARCH 2022 – REVISED OCTOBER 2022

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INA849 Datasheet(PDF) 32 Page - Texas Instruments