Texas Instruments APA100 Stereo Amplifier User Manual


 
Thermal
4-12
As an indication of the importance of keeping the thermal grease layer thin, if
the thermal grease layer increases to 0.002 inch thick, the required heatsink
thermal resistance changes to 2.4°C/W.
The large heatsink used for the APA100 EVM is required for full output power
sine waves over temperature. A smaller heatsink can be used for music, which
requires much less average power.
The heatsink should be tight without bending the board or damaging the IC.
However, there should be slight dimpling of the boards around the screws.
Heatsink screws were tightened with a torque of 1.5 inch−pounds on the
APA100 board. A washer and lock−washer can be used to help secure the
heatsink, but is not required in most applications.