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).