SLOS375B August 2014 – February 2024 THS4541
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The relatively low internal quiescent power dissipation for the THS4541, combined with the excellent thermal impedance of the 16-pin VQFN (RGT) package, limits the possibility of excessively-high, internal-junction temperatures. The 10-pin WQFN (RUN) package has a much higher junction-to-ambient thermal impedance (θJA = 146°C/W); therefore, a more detailed analysis can be warranted.
To estimate the internal junction temperature (TJ), an estimate of the maximum internal power dissipation (PD) is first required. There are two pieces to the internal power dissipation: quiescent current power and the power used in the output stage to deliver load current. To simplify the latter, the worst-case, output-stage power is driving a dc differential voltage across a load using half the total supply voltage. As an example:
Even for this extreme condition and the maximum rated ambient temperature of 125°C, the junction temperature is a maximum 144°C (less than the rated absolute maximum of 150°C). Follow this same calculation sequence for the exact application and package selected to predict the maximum TJ.