Datasheet

OPA354-Q1
OPA2354-Q1
www.ti.com ....................................................................................................................................................... SBOS492A –JUNE 2009–REVISED AUGUST 2009
Power Dissipation
Power dissipation depends on power-supply voltage, signal and load conditions. With dc signals, power
dissipation is equal to the product of output current times the voltage across the conducting output transistor,
V
S
– V
O
. Power dissipation can be minimized by using the lowest possible power-supply voltage necessary to
assure the required output voltage swing.
For resistive loads, the maximum power dissipation occurs at a dc output voltage of one-half the power-supply
voltage. Dissipation with ac signals is lower. Application bulletin AB-039 (SBOA022), Power Amplifier Stress and
Power Handling Limitations, explains how to calculate or measure power dissipation with unusual signals and
loads, and can be found at www.ti.com.
Any tendency to activate the thermal protection circuit indicates excessive power dissipation or an inadequate
heatsink. For reliable operation, junction temperature should be limited to 150°C, maximum. To estimate the
margin of safety in a complete design, increase the ambient temperature until the thermal protection is triggered
at 160°C. The thermal protection should trigger more than 35°C above the maximum expected ambient condition
of the application.
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