JAJSH51C August 2000 – March 2024 BUF634
PRODUCTION DATA
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, VS – VO. Power dissipation can be minimized by using the lowest possible power supply voltage necessary to provide 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. The Power Amplifier Stress And Power Handling Limitations application bulletin explains how to calculate or measure power dissipation with unusual signals and loads.
Any tendency to activate the thermal protection circuit indicates excessive power dissipation or an inadequate heat sink. For reliable operation, limit the junction temperature to 150°C, maximum. To estimate the margin of safety in a complete design, increase the ambient temperature until the thermal protection is triggered. The thermal protection triggers more than 45°C greater than the maximum expected ambient condition of your application.